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BACKGROUND: The impact of renin-angiotensin system blockade (RASB) on the incidence of end-stage renal disease (ESRD) remains unclear in IgA nephropathy (IgAN). METHODS: This study assessed associations between RASB treatment and the incidence of ESRD in IgAN using propensity score approaches. We retrospectively analyzed 1273 patients with IgAN biopsied between 1979 and 2010. Propensity scores were calculated using logistic regression. Associations between RASB and ESRD were examined using a Cox regression model adjusted by inverse probability of treatment weighted, regression, stratification and matching. RESULTS: During follow-up (median 5.1 years), 130 patients developed ESRD. With Cox regression adjusted by inverse probability of treatment weighted, RASB use was significantly associated with a lower risk of ESRD (hazard ratio 0.58; 95 &#37; confidence interval 0.42-0.80). Significant associations were observed for other propensity score-based approaches. In stratified analysis, a beneficial association between RASB and ESRD was observed in patients ≥35 years, with hypertension, reduced estimated glomerular filtration rate (<60 mL/min/1.73 m2), mesangial proliferation and segmental glomerulosclerosis (P for interaction <0.05), and tended to be greater in patients with proteinuria (≥1.0 g/24 h), extracapillary proliferation and receiving methylprednisolone pulse therapy (P for interaction <0.10). CONCLUSION: Treatment with RASB was associated with a lower incidence of ESRD in the real-world practice of IgAN.

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BACKGROUND: Hemodialysis patients who receive vitamin D receptor activator (VDRA) reportedly have better survival after infection than those who do not. However, the optimal route of its administration for minimizing death from infection remains unclear. METHODS: This prospective cohort study aimed to compare the effectiveness of oral versus intravenous VDRA regarding infection-related mortality in 3372 hemodialysis patients. Eligible subjects were divided into the following three groups by route of administration of VDRA: oral (n = 1868), intravenous (n = 492) and not administered (n = 1012). The effect of VDRA on infection-related mortality was examined using a Cox regression model with propensity score-based adjustments. RESULTS: During follow-up (median, 4.0 years), 118 study patients died of infection. There was a significantly lower incidence of death from infection in subjects who received intravenous VDRA than in those who did not receive VDRA; however, oral VDRA did not significantly reduce the risk of mortality from infection compared with those who did not receive VDRA [hazard ratio (HR) for intravenous VDRA, 0.16; 95&#37; confidence interval (CI), 0.10-0.25, and HR for oral VDRA, 0.78; 95&#37; CI, 0.60-1.01]. Direct comparison between the oral and intravenous VDRA groups showed that the intravenous group had significantly better survival than the oral group (HR, 0.39; 95&#37; CI, 0.27-0.62). CONCLUSIONS: Treatment with intravenous VDRA more effectively reduces the incidence of mortality from infection than oral VDRA in hemodialysis patients.

DOI： 10.1093/ndt/gfw205

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BACKGROUND: Serum bilirubin has been recognized as a novel endogenous antioxidant. The aim of our study was to evaluate the impact of serum bilirubin on kidney prognosis in IgA nephropathy (IgAN). METHODS: We followed retrospectively 694 patients with IgAN diagnosed by renal biopsy between 1982 and 2010. The risk factors for developing end-stage renal disease (ESRD) were estimated using a Cox proportional hazard model. Predictive performance between models with or without serum bilirubin was evaluated by calculating the net reclassification improvement (NRI) and integrated discrimination improvement (IDI). RESULTS: Seventy-seven patients developed ESRD during the median 4.9 years of follow-up. Estimated glomerular filtration rate, proteinuria and histological severity were inversely related to bilirubin levels. In multivariate analysis, serum bilirubin was an independent risk factor for ESRD (hazard ratio for every 0.1 mg/dL decrease in serum bilirubin, 1.18; 95 &#37; CI, 1.04-1.33). The incidence rate of ESRD decreased linearly with the increases in bilirubin levels (P for trend <0.01). When bilirubin was incorporated into a model with conventional ESRD risk factors, the NRI and IDI were 0.281 (P = 0.02) and 0.019 (P = 0.01), respectively. CONCLUSIONS: We demonstrated that lower bilirubin levels were significantly associated with higher risk of ESRD in IgAN. In addition, bilirubin provided incremental predictive value in the risk assessment for progression of IgAN beyond that provided by standard risk factors.

DOI： 10.1007/s10157-015-1096-0

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BACKGROUND AND OBJECTIVES: The risk assessment for developing ESRD remains limited in patients with IgA nephropathy (IgAN). The aim of this study was to develop and validate a prediction rule for estimating the individual risk of ESRD in patients with IgAN. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 698 patients with IgAN diagnosed by renal biopsy at Kyushu University Hospital (derivation cohort) between 1982 and 2010 were retrospectively followed. The Oxford classification was used to evaluate the pathologic lesions. The risk factors for developing ESRD were evaluated using a Cox proportional hazard model with a stepwise backward elimination method. The prediction rule was verified using data from 702 patients diagnosed at Japanese Red Cross Fukuoka Hospital (validation cohort) between 1979 and 2002. RESULTS: In the derivation cohort, 73 patients developed ESRD during the median 4.7-year follow-up. The final prediction model included proteinuria (hazard ratio [HR], 1.30; 95&#37; confidence interval [95&#37; CI], 1.16 to 1.45, every 1 g/24 hours), estimated GFR (HR, 0.84; 95&#37; CI, 0.74 to 0.96, every 10 ml/min per 1.73 m(2)), mesangial proliferation (HR, 1.85; 95&#37; CI, 1.10 to 3.11), segmental sclerosis (HR, 3.21; 95&#37; CI, 1.37 to 7.51), and interstitial fibrosis/tubular atrophy (T1: HR, 5.30; 95&#37; CI, 2.63 to 10.7; T2: HR, 20.5; 95&#37; CI, 9.05 to 46.5) as independent risk factors for developing ESRD. To create a prediction rule, the score for each variable was weighted by the regression coefficients calculated using the relevant Cox model. The incidence of ESRD increased linearly with increases in the total risk scores (P for trend <0.001). Furthermore, the prediction rule demonstrated good discrimination (c-statistic=0.89) and calibration (Hosmer-Lemeshow test, P=0.78) in the validation cohort. CONCLUSIONS: This study developed and validated a new prediction rule using clinical measures and the Oxford classification for developing ESRD in patients with IgAN.

DOI： 10.2215/CJN.03480413

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BACKGROUND: The association between microscopic hematuria (MH) and albuminuria in patients with chronic kidney disease (CKD) caused by diabetes and hypertension remains unclear. METHODS: The Fukuoka Kidney disease Registry Study is a Japanese multicenter prospective cohort study of 4476 patients with non-dialysis-dependent CKD. In this cohort, we conducted a cross-sectional study in 994 patients with diabetic nephropathy and hypertensive nephrosclerosis. Patients were divided into three groups according to erythrocyte count in urine sediment [T1: < 5/high power field (HPF); T2: 5-9/HPF; T3: ≥ 10/HPF]. Macroalbuminuria was defined as urinary albumin-creatinine ratio > 300 mg/g. Associations between the degree of MH (T1-T3) and the prevalence of macroalbuminuria were analyzed using logistic regression. RESULTS: The prevalence of macroalbuminuria was 50.8&#37;, 50.4&#37;, and 67.4&#37; in T1 (n = 725), T2 (n = 226), and T3 (n = 43), respectively. The multivariable-adjusted odds ratios for the presence of macroalbuminuria were 0.95 [95&#37; confidence interval (CI) 0.65-1.39; P = 0.86] and 2.50 (95&#37; CI 1.15-5.47; P = 0.022) for patients in T2 and T3, respectively, compared with patients in T1. CONCLUSIONS: MH with erythrocytes ≥ 10/HPF was significantly associated with increased prevalence of macroalbuminuria in patients with non-dialysis-dependent CKD caused by diabetes and hypertension.

DOI： 10.1007/s10157-022-02298-7

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BACKGROUND: Hypertriglyceridemia is increasingly considered a residual risk of cardiovascular disease in patients with chronic kidney disease (CKD). Pemafibrate-a novel selective peroxisome proliferator-activated receptor alpha modulator and a new treatment for hypertriglyceridemia in CKD patients-is reported to have fewer side effects in CKD patients than other fibrates. Appropriate control of hypertriglyceridemia can be expected to improve renal prognosis. However, data on the renal protective effect of pemafibrate are limited. This study aims to evaluate the effectiveness of pemafibrate on urinary protein excretion in CKD patients. METHODS: The Pemafibrate, open-label, Randomized cOntrolled study to evaluate the renal protective eFfect In hyperTriglyceridemia patients with Chronic Kidney Disease (PROFIT-CKD) study is an investigator-initiated, multi-center, open-label, parallel-group, randomized controlled trial. Participants are outpatients with hypertriglyceridemia aged 20 years and over, who have received the care of a nephrologist or a diabetologist for more than 3 months. Inclusion criteria include the following: proteinuria (urine protein/creatinine ratio of ≥ 0.15 g/gCr) within three months before allocation, and hypertriglyceridemia (triglycerides ≥ 150 mg/dL and < 1,000 mg/dL) at allocation. In the treatment group, pemafibrate is added to conventional treatment, while conventional treatment is continued with no additional treatment in the control group. Target patient enrollment is 140 patients. The primary endpoint is the change from baseline in the logarithmic urine protein/creatinine ratio at 12 months after study start. CONCLUSION: This study will provide new findings on the renal protective effect of pemafibrate in CKD patients. CLINICAL TRIAL REGISTRATION: This clinical trial was registered at the University Hospital Medical Information Network (UMIN) Center (UMIN-CTR: UMIN000042284).

DOI： 10.1007/s10157-023-02322-4

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AIM: Cardiovascular disease is a life-threatening chronic kidney disease (CKD) complication. Although cardiovascular risk factor management is significant in patients with CKD, there are few reports that detail the frequency of complications and the treatment of cardiovascular risk factors at different stages of CKD in clinical practice. METHODS: There were a total of 3,407 patients with non-dialysis-dependent CKD who participated in the Fukuoka Kidney disease Registry Study, and they were cross-sectionally analyzed. The patients were classified into five groups based on their estimated glomerular filtration rate and urinary albumin to creatinine ratio according to Kidney Disease: Improving Global Outcomes 2012 guidelines, which recommend low, moderate, high, very high, and extremely high risk groups. The primary outcomes were the cardiovascular risk factor burden and the treatment status of cardiovascular risk factors. Using a logistic regression model, the association between the CKD groups and the treatment status of each risk factor was examined. RESULTS: The proportion of patients with hypertension, diabetes mellitus, and dyslipidemia significantly increased as CKD progressed, whereas the proportion of patients who achieved cardiovascular risk factor treatment targets significantly decreased. In the multivariable analysis, the odds ratios (ORs) of uncontrolled treatment targets were significantly higher for hypertension (OR 3.68) in the extremely high risk group than in the low risk group. CONCLUSIONS: Patients with non-dialysis-dependent CKD demonstrate an increased cardiovascular risk factor burden with greater severity of CKD. Extremely high risk CKD is associated with difficulty in managing hypertension.

DOI： 10.5551/jat.63891

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Patients with chronic kidney disease (CKD) occasionally need to restrict their consumption of vegetables and fruits. However, recent evidence suggests that plant-based diets have beneficial effects in patients with CKD. We aimed to determine the sufficiency of β carotene and dietary fiber intake in patients with CKD. We conducted a cross-sectional study among 4476 patients registered in the Fukuoka Kidney Disease Registry (FKR) study, a Japanese prospective cohort study of patients with CKD. Data from 3545 patients were analyzed after excluding cases with insufficient information. We evaluated the relationship between CKD stages and the intake of vegetables and fruits. The intake of β carotene and dietary fiber in CKD stages was evaluated using analysis of covariance. As the CKD stage advanced, the intake of vegetables, green leafy vegetables, and fruits significantly decreased (P-value for all trends < 0.01). The intake of vegetables significantly decreased as the CKD stage advanced (P for trend < 0.01). After adjusting for confounding factors, the intake of β carotene and dietary fiber also decreased (both P < 0.01) as the CKD stage advanced. Patients with CKD had insufficient vegetable and fruit intake and a lack of β carotene and dietary fiber from vegetables and fruits.

DOI： 10.1038/s41598-022-24471-4

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BACKGROUND: High serum alkaline phosphatase (ALP) levels are associated with excess all-cause and cardiovascular mortality in patients undergoing hemodialysis (HD). However, the long-term relationship between serum ALP levels and infection-related mortality remains unclear. METHODS: A total of 3502 maintenance HD patients were registered in the Q-Cohort Study, an observational cohort study in Japan. The primary outcome was infection-related mortality during a 10-year follow-up period. The covariate of interest was serum ALP levels at baseline. The association between serum ALP levels and infection-related mortality was calculated using a Cox proportional hazards model and a Fine-Gray subdistribution hazards model with non-infection-related death as a competing risk. RESULTS: During the follow-up period, 446 patients died of infection. According to their baseline serum ALP levels, the patients were categorized into sex-specific quartiles (Q1-Q4). Compared with patients in the lowest serum ALP quartile (Q1), those in the highest quartile (Q4) had a significantly higher multivariable-adjusted hazard ratio (HR) of 1.70 [95&#37; confidence interval (CI) 1.24-2.32] for infection-related mortality. Furthermore, the HR for every 50 U/L increase in serum ALP levels was 1.24 (95&#37; CI 1.12-1.36) for infection-related mortality. These associations remained consistent in the competing risk model: subdistribution HR, 1.47; 95&#37; CI 1.07-2.03 for Q4 compared with Q1. CONCLUSION: Higher serum ALP levels were significantly associated with a higher risk of infection-related mortality in patients undergoing HD.

DOI： 10.1007/s10157-022-02255-4

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BACKGROUND: Hypertension is an important prognostic predictor in patients with chronic kidney disease (CKD), and the recommended target blood pressure has been continuously revised. This study aimed to reveal the current antihypertensive practices in Japanese patients with CKD. METHODS: In the Fukuoka Kidney disease Registry, we extracted 3664 non-dialysis-dependent patients with CKD. Apparent treatment-resistant hypertension (aTRH) was defined as a failure of blood-pressure control treated with three antihypertensive medication classes or a treatment with ≥ 4 classes regardless of blood pressure. The blood-pressure control complied with the target blood pressure recommended by the KDIGO 2012 guideline. RESULTS: The median age of the patients was 67 years, body mass index (BMI) was 23 kg/m2, and estimated glomerular filtration rate (eGFR) was 40 mL/min/1.73 m2. The number of patients with unachieved blood-pressure control was 1933, of whom 26&#37; received ≥ 3 classes of antihypertensive medications. The first choice of medication was renin-angiotensin system inhibitors, followed by calcium-channel blockers. The rate of thiazide use was low in all CKD stages (3-11&#37;). The prevalence of aTRH was 16&#37;, which was significantly associated with BMI (odds ratio [95&#37; confidence interval] per 1-standard deviation change, 1.38 [1.25-1.53]), decreased eGFR (1.87 [1.57-2.23]), as well as age, diabetes mellitus, and chronic heart disease. CONCLUSIONS: Renal dysfunction and obesity are important risk factors of aTRH. Even under nephrologist care, most patients were treated with insufficient antihypertensive medications. It is important to prescribe sufficient classes of antihypertensive medications, including diuretics, and to improve patients' lifestyle habits.

DOI： 10.1007/s10157-022-02250-9

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BACKGROUND: Constipation is a common complication in patients with chronic kidney disease (CKD) and is involved in the pathogenesis of dysbiosis and progression of CKD. However, little is known about its association with disorders of the bone-cardiovascular axis in patients with CKD. METHODS: We performed a cross-sectional analysis of 3878 patients with CKD using the baseline dataset of the Fukuoka Kidney disease Registry study, as a multicenter, prospective cohort study of pre-dialysis CKD patients. The main exposure of interest was constipation defined as use of at least one type of laxative. The main outcomes were the histories of bone fractures and cardiovascular diseases (CVDs) as manifestations of disorders of the bone-cardiovascular axis. RESULTS: The prevalences of laxative use and histories of bone fractures and CVDs increased as kidney function declined. Among the 3878 patients, 532 (13.7&#37;) patients used laxatives, 235 (6.1&#37;) patients had prior bone fractures, and 1001 (25.8&#37;) patients had prior CVDs. Histories of bone fractures and CVDs were significantly more prevalent among laxative users (P < 0.05). Multivariable-adjusted logistic regression analysis revealed that patients with laxatives had a significantly higher odds ratios for histories of bone fractures and CVDs than those without laxatives [adjusted odds ratios (95&#37; confidence intervals) 1.67 (1.20-2.31) and 1.70 (1.30-2.22), respectively, P < 0.05]. CONCLUSIONS: These results suggest that constipation indicated by laxative use is associated with increased prevalences of historical bone fractures and CVDs in pre-dialysis patients with CKD.

DOI： 10.1007/s10157-022-02289-8

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BACKGROUND: In 2012, we established a CKD network in collaboration with the public health service, primary care physicians, and nephrologists in the Kasuya area. The aim of this study was to clarify if our CKD network was effective in preventing CKD progression. METHODS: 1591 subjects, who had CKD in health checks in 2012 were included in this study. The slope of estimated glomerular filtration rate (eGFR) was compared before and after 2012. Parameters at the first health check visit before 2012, visit in 2012, and the last visit after 2012, were compared. Paired t test, analysis of variance for repeated measurements, and the Friedman test were used for the analysis. RESULTS: Mean age was 65 years. There were 781 men and 810 women. Mean eGFR was 59 ml/min/1.73 m2. The mean slope of eGFR before 2012 was -1.833 ml/min/1.73 m2/year and significantly reduced to - 0.297 after 2012. Low-density lipoprotein cholesterol showed a significant serial lowering. Uric acid was significantly elevated in 2012 compared to the first visit and had decreased by the last. The dipstick urinary protein significantly increased in 2012 compared to the first visit and decreased by the last. The number of current smokers showed a significant reduction over time. On the other hand, systolic blood pressure (SBP) and HbA1c significantly elevated at the last visit. CONCLUSION: The Kasuya CKD network may be effective in preventing CKD progression.

DOI： 10.1007/s10157-022-02267-0

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AIM: The Controlling Nutritional Status (CONUT) score and the Prognostic Nutritional Index (PNI) reflect the immunonutritional status of patients. However, the associations of these two indices with cardiovascular disease (CVD) have not been characterized in patients with chronic kidney disease (CKD). Therefore, the current study aimed to determine whether the CONUT score or PNI was associated with prior CVD in patients with CKD. METHODS: A cross-sectional study of 2,751 patients with CKD who were not on dialysis was performed. The patients were grouped into tertiles (T1-T3) of PNI and placed into three groups following their CONUT score: low- (CONUT score, 0), mild- (CONUT score, 1-2), and moderate-to-high- (CONUT score, ≥ 3) risk groups. RESULTS: Prior CVD was present in 655 (24&#37;) of the participants. Multivariable logistic regression analyses, with adjustment for potential confounders, showed that high CONUT score was associated with prior CVD than the low score (mild-risk group: odds ratio [OR]=1.35, 95&#37; confidence interval [CI]=1.04-1.76; moderate-to-high-risk group: OR=1.66, 95&#37; CI=1.19-2.30). In addition, the lower PNI tertiles were independently associated with prior CVD compared with T3 of PNI (T1: OR=1.45, 95&#37; CI=1.09-1.92; T2: OR=1.32, 95&#37; CI=1.01-1.72). CONCLUSIONS: Both CONUT score and PNI were found to be independently associated with prior CVD in patients with CKD in the present cross-sectional study. A longitudinal study is needed to elucidate whether these two indices are associated with subsequent cardiovascular events.

DOI： 10.5551/jat.63501

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BACKGROUND: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) has been highlighted as a potential risk factor for cardiovascular disease in patients with chronic kidney disease (CKD). METHODS: We assessed cross-sectionally the prevalence, associated factors, and treatment status of anemia and ESA hyporesponsiveness in 4460 non-dialysis-dependent CKD patients enrolled in a multicenter cohort in Japan. Anemia was defined as a hemoglobin (Hb) level of less than 11 g/dL or receiving ESA therapy. ESA hyporesponsiveness was defined by the erythropoietin-resistance index (ERI), which was the erythropoietin dose per week divided by body weight and Hb level (U/kg/week/g/dl). RESULTS: Of the 4460 patients, 1050 (23.5&#37;) had anemia. ESAs were administered to 626 patients, reaching a percentage of 57.5&#37; of patients with stage G5 CKD. However, the ESA treatment rate was only 49.0&#37; in patients with a hemoglobin level of < 11 g/dL. The proportion of patients receiving iron supplementation was lower than that of patients receiving ESAs regardless of CKD stage or hemoglobin level, and a significant proportion of patients did not receive iron supplementation, even those with iron deficiency. The ERI increased with CKD stage progression, and the multiple regression analysis showed that age, female sex, body mass index, cholesterol, glomerular filtration rate, and intact parathyroid hormone level were independent contributors. CONCLUSIONS: Our findings demonstrate that many Japanese patients with non-dialysis-dependent CKD receiving ESAs fail to maintain adequate hemoglobin levels. These results suggest the need for interventions for ESA hyporesponsiveness factors in addition to iron supplementation.

DOI： 10.1007/s10157-022-02227-8

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AIM: Individuals with chronic kidney disease (CKD) have a high prevalence of comorbidities, including cardiovascular disease (CVD) and its risk factors. However, epidemiological results to assess the association between multimorbidity and kidney function among the CKD population remains limited. METHODS: We performed a cross-sectional analysis of the association between 23 comorbid conditions and reduced kidney function in 4,476 patients with non-dialysis-dependent CKD enrolled in a multicenter cohort in Japan. Reduced kidney function was defined as an estimated glomerular filtration rate of ≤ 60 mL/min/1.73 m2. RESULTS: The mean age of patients was 67 years (male, 56.0&#37;). The prevalence of hypertension, diabetes mellitus, dyslipidemia, prior CVD, cancer, and bone fracture, which are the major comorbidities, was 83.3&#37;, 28.7&#37;, 45.9&#37;, 23.3&#37;, 12.7&#37;, and 6.3&#37;, respectively. Multivariable-adjusted analyses revealed that age, male sex, hypertension, dyslipidemia, prior CVD, body mass index, urinary protein excretion, and underlying kidney disease were independent factors associated with reduced kidney function. Importantly, the odds ratios (ORs) for reduced kidney function increased linearly as the number of major comorbid conditions increased (OR for 1-2 conditions: 2.22, 95&#37; confidence interval [CI]: 1.65-2.97; OR for 3-4 conditions: 3.04, 95&#37; CI: 2.12-4.37; OR for ≥ 5 conditions: 4.37, 95&#37; CI: 1.75-10.9). The upward trend in OR was more pronounced with cardiovascular comorbidities but not significant with non-cardiovascular comorbidities. CONCLUSIONS: In conclusion, we observed an independent association between cardiovascular comorbidity and its risk factors and reduced kidney function. The results of this study highlight the importance of managing multimorbidity among patients with CKD.

DOI： 10.5551/jat.62900

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BACKGROUND: A growing body of evidence has shown that non-alcoholic fatty liver disease (NAFLD) is associated with chronic kidney disease (CKD). Non-invasive fibrosis assessments of NAFLD such as Fibrosis-4 (FIB-4) index and NAFLD fibrosis score (NFS) have been developed to substitute liver biopsy. Little is known about the association between FIB-4 index or NFS and the components of CKD. METHODS: In the present cross-sectional study, we assessed of 3640 Japanese CKD patients. We examined the association between FIB-4index or NFS and the odds of having low estimated glomerular filtration rate (eGFR) defined as eGFR < 60 mL/min/1.73 m2 or albuminuria defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Patients were divided into quartiles according to their baseline FIB-4 index and NFS levels. Linear and logistic regression analysis were conducted, with adjustment for potential confounding factors. RESULTS: FIB-4 index and NFS were negatively associated with eGFR, but not UACR, after adjustment for potential confounding factors. Both FIB-4 index and NFS were significantly associated with low eGFR after adjustment for potential confounding factors. Meanwhile, in the multivariable-adjusted model, no associations were found between FIB-4 index or NFS and albuminuria. The addition of FIB-4 index or NFS to the established clinical CKD risk factors improved diagnostic accuracy of prevalence of low eGFR. We also found that there was a significant trend of higher FIB-4 index and NFS with more advanced renal fibrosis using the kidney biopsy data. CONCLUSIONS: Higher non-invasive fibrosis assessments of NAFLD were associated with higher odds of decreased eGFR.

DOI： 10.1007/s10157-020-02018-z

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In recent years, large cohort studies of patients with chronic kidney disease (CKD) have been established all over the world. These studies have attempted to analyze the pathogenesis of CKD using a large body of published evidence. The design of cohort studies is characterized by the measurement of the exposure prior to the occurrence of the outcome, which has the advantage of clarifying the temporal relationship between predictors and outcomes and estimating the strength of the causal relationship between predictors and multiple outcomes. Recent advances in biostatistical analysis methods, such as propensity scores and risk prediction models, are facilitating causal inference using higher quality evidence with greater precision in observational studies. In this review, we will discuss clinical epidemiological research of kidney disease based on the analysis of observational cohort data sets, with a focus on our previous studies.

DOI： 10.1007/s10157-021-02121-9

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INTRODUCTION: Angiotensin receptor blockers (ARBs) are preferably used in hypertensive patients with CKD. Azilsartan is a strong antihypertensive ARB, but its antiproteinuric effects are not well understood. We compared the antiproteinuric effect of azilsartan and candesartan in CKD patients in an open-label, randomized, crossover trial. METHODS: A total of 111 patients were treated with 20 mg of azilsartan daily for 2 months as a run-in period. After the run-in period, patients were randomized into 2 arms and received either 20 mg of azilsartan or 8 mg of candesartan daily for 3 months in a crossover trial. The primary outcome was the percent change in urinary protein-to-Cr ratio (UPCR). RESULTS: Ninety-five patients completed the trial. The mean age was 64.3 years. The estimated glomerular filtration rate (eGFR) and UPCR were 41.5 mL/min/1.73 m2 and 1.8 g/gCr, respectively. The baseline systolic and diastolic blood pressures were 131.4 and 71.0 mm Hg, respectively. The mean percent change in the UPCR was -3.8&#37; in the azilsartan group and 30.8&#37; in the candesartan group at the 1st endpoint (p = 0.0004), and 6.1&#37; in the azilsartan group and 25.8&#37; in the candesartan group at the 2nd (final) endpoint (p = 0.029). The incidence of adverse events, including eGFR levels and serum potassium levels, was not significantly different between the groups. CONCLUSION: A 20 mg azilsartan dose had potent antiproteinuric effects compared with an 8 mg candesartan dose, without an increase in adverse events. Azilsartan may provide renal protection in addition to antihypertensive effects in CKD patients.

DOI： 10.1159/000512365

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BACKGROUND: Patients with chronic kidney disease (CKD) have a higher risk of atherosclerotic cardiovascular disease (ASCVD). Dyslipidemia has been established as a risk factor for ASCVD. In the present study, we aimed to determine the prevalence of dyslipidemia at each stage of CKD. METHODS: We conducted a cross-sectional study among 4476 patients registered in the Fukuoka Kidney Disease Registry Study, a Japanese prospective cohort study in patients with non-dialysis-dependent CKD. Outcomes were the prevalence of hyper-low-density lipoprotein (LDL) cholesterolemia, hyper-non-high-density lipoprotein (non-HDL) cholesterolemia, hypertriglyceridemia, and hypo-high-density lipoprotein (hypo-HDL) cholesterolemia at each stage of CKD. We analyzed the relationships between CKD stage and the prevalence of dyslipidemia using logistic regression models. RESULTS: Patients in the advanced stages of CKD were more likely to have hypertriglyceridemia [OR 2.16 (95&#37; CI 1.03-4.56), OR 2.24 (95&#37; CI 1.04-4.84), OR 2.62 (95&#37; CI 1.19-5.78), and OR 2.47 (95&#37; CI 1.04-5.88) for CKD stages G3a, G3b, G4, and G5, respectively] and hypo-HDL-cholesterolemia [OR 2.66 (95&#37; CI 1.21-5.82), OR 3.10 (95&#37; CI 1.38-6.95), OR 2.86 (95&#37; CI 1.25-6.53), and OR 3.30 (95&#37; CI 1.35-8.10) for CKD stages G3a, G3b, G4, and G5, respectively] as compared with patients in CKD stage G1. The prevalence of hyper-LDL-cholesterolemia and hyper-non-HDL-cholesterolemia was not related to CKD stage. CONCLUSION: Patients with advanced CKD stages are more likely to have hypertriglyceridemia and hypo-HDL-cholesterolemia than those in early stages. This type of lipid profile may represent a risk factor for ASCVD in patients with CKD.

DOI： 10.1007/s10157-020-02000-9

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AIM: Multivascular disease, indicating concurrent arteriosclerotic lesions in a number of different vascular beds, is an independent risk factor for recurrent ischemic events in the general population. However, the impact of multivascular disease on the risk of developing cardiovascular disease has not been fully evaluated in patients receiving hemodialysis. METHODS: A total of 3,504 hemodialysis patients were prospectively followed for 10 years. In this study, multivascular disease was defined as the coexistence of coronary artery disease and stroke. We examined the relationship between multivascular disease and the occurrence of composite cardiovascular endpoint, consisting of cardiovascular death, nonfatal coronary artery disease, nonfatal stroke, and peripheral artery disease. RESULTS: The proportion of participants with multivascular disease was 5.7&#37; (n=200) at baseline. During follow-up (median, 106.6 months; interquartile range, 50.1-121.8 months), 1,311 patients experienced the composite endpoint, which was defined as at least one of the following: cardiovascular death (n=620), nonfatal coronary artery disease (n=318), nonfatal stroke (n=340), and peripheral artery disease (n=257). Compared with the group with no history of cardiovascular disease, the risk of experiencing the composite endpoint increased significantly with higher numbers of injured vascular beds in patients with single vascular disease (hazard ratio, 1.68; 95&#37; confidence interval, 1.49-1.89) and in those with multivascular disease (hazard ratio, 2.11; 95&#37; confidence interval, 1.71-2.60). In a multivariable analysis, multivascular disease was an independent predictor of cardiovascular events, in addition to diabetes, aging, and hypertension. CONCLUSIONS: This study clearly demonstrated that multivascular disease was a powerful predictor for cardiovascular mortality and morbidity in patients receiving hemodialysis.

DOI： 10.5551/jat.54098

Language：English   Publishing type：Research paper (scientific journal)  

Patients with chronic kidney disease (CKD) are at increased risks of both sarcopenia and fragility fractures. However, information on the association between skeletal muscle mass (SMM) and the risk of bone fractures in patients with CKD is lacking. We performed a cross-sectional analysis of 4146 patients with CKD using the baseline dataset of the Fukuoka Kidney disease Registry Study, as a multicenter, prospective cohort study of pre-dialysis CKD patients. The main measure was estimated SMM (eSMM) calculated using an equation validated by bioelectrical impedance analysis with two independent datasets of 100 and 81 CKD patients. The main outcome was historical bone fractures. The associations between sex-specific quartiles (Q1-Q4) of eSMM and fracture history were assessed by logistic regression analyses. The prevalence of a history of fractures increased and eSMM decreased with progressive CKD stages. Among the 4146 patients, 249 had prior bone fractures, including 111 patients in Q1 (lowest quartile), 65 in Q2, 46 in Q3, and 27 in Q4 (highest quartile). A multivariable-adjusted model revealed that patients in Q1 had a significantly higher odds ratio (95&#37; confidence interval) for bone fracture history than those in Q4 (reference): Q1, 2.77 (1.32-5.80); Q2, 1.95 (1.05-3.65); and Q3, 1.57 (0.90-2.75) (P-value for trend < 0.001). Similar associations were obtained when other skeletal muscle surrogates were applied: serum creatinine to serum cystatin C and daily urinary creatinine excretion. These results suggest that a lower eSMM is associated with an increased prevalence of historical bone fractures in pre-dialysis CKD patients.

DOI： 10.1007/s00223-021-00851-2

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUNDS AND AIMS: The geriatric nutritional risk index (GNRI), which is calculated using the serum albumin level and body mass index, is a nutritional marker associated with an increased risk of cardiovascular events in patients who are receiving hemodialysis. However, no studies have examined the association between the GNRI level and the incidence of stroke in this population. METHODS: Three thousand forty-five patients were registered in the Q-Cohort Study, which is a multicenter, observational cohort of hemodialysis patients. The main outcomes were brain infarction and brain hemorrhage. The main exposure was GNRI levels at baseline. Patients were divided into quartiles on the basis of baseline GNRI levels: Q1, <90.7; Q2, 90.7-95.5; Q3, 95.6-99.8; Q4, >99.8. The risk of brain infarction or hemorrhage was estimated using the multivariable-adjusted Cox proportional hazard risk models and restricted cubic spline analyses. RESULTS: During the 10-year follow-up period, 326 patients developed brain infarction and 149 patients developed brain hemorrhage. Cox proportional hazard risk models showed that the risk of brain infarction and hemorrhage in Q1 was significantly higher than that in Q4 group. The hazard ratios [95&#37; confidence intervals] were 1.49 [1.05-2.12] and 1.89 [1.11-3.20], respectively. Restricted cubic spline curves showed that a lower GNRI was incrementally associated with an increased risk for both brain infarction and brain hemorrhage. CONCLUSIONS: Our results suggest that a lower GNRI is an independent risk factor for both brain infarction and hemorrhage in patients who are receiving maintenance hemodialysis.

DOI： 10.1016/j.atherosclerosis.2021.03.006

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Background: Previous studies have shown that hyponatremia is associated with greater mortality in hemodialysis (HD) patients. However, there have been few reports regarding the importance of the change in serum sodium (SNa) concentration (ΔSNa) during dialysis sessions. To investigate the relationships of pre-dialysis hyponatremia and ΔSNa during a dialysis session with mortality, we analyzed data from a national registry of Japanese patients with end-stage kidney disease. Methods: We identified 178,114 patients in the database who were undergoing HD 3 times weekly. The study outcome was 2-year all-cause mortality, and the baseline SNa concentrations were categorized into quintiles. We evaluated the relationships of SNa concentration and ΔSNa with mortality using Cox proportional hazards models. Results: During a 2-year follow-up period, 25,928 patients died. Each 1-mEq/l reduction in pre-HD SNa concentration was associated with a cumulatively greater risk of all-cause mortality (hazard ratio [HR], 1.05; 95&#37; confidence interval [CI], 1.05-1.06). In contrast, a larger ΔSNa was associated with higher all-cause mortality (HR for a 1-mEq/l increase in ΔSNa, 1.02; 95&#37; CI 1.01-1.02). The combination of low pre-HD SNa concentration and large ΔSNa was also associated with higher mortality (HR 1.09; 95&#37; CI 1.05-1.13). Participants with the lowest SNa concentration (≤136 mEq/L) and the highest ΔSNa (>4 mEq/L) showed higher mortality than those with an intermediate pre-HD SNa concentration (137-140 mEq/L) and the lowest ΔSNa (≤2 mEq/L). Conclusions: Lower pre-HD SNa concentration and higher ΔSNa are associated with a greater risk of mortality in patients undergoing HD.

DOI： 10.1016/j.ekir.2020.11.009

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BACKGROUND: Cardiovascular disease (CVD) is a major cause of death in kidney transplant (KT) recipients. To improve their long-term survival, it is clinically important to estimate the risk of CVD after living donor KT via adequate pre-transplant CVD screening. METHODS: A derivation cohort containing 331 KT recipients underwent living donor KT at Kyushu University Hospital from January 2006 to December 2012. A prediction model was retrospectively developed and risk scores were investigated via a Cox proportional hazards regression model. The discrimination and calibration capacities of the prediction model were estimated via the c-statistic and the Hosmer-Lemeshow goodness of fit test. External validation was estimated via the same statistical methods by applying the model to a validation cohort of 300 KT recipients who underwent living donor KT at Tokyo Women's Medical University Hospital. RESULTS: In the derivation cohort, 28 patients (8.5&#37;) had CVD events during the observation period. Recipient age, CVD history, diabetic nephropathy, dialysis vintage, serum albumin and proteinuria at 12 months after KT were significant predictors of CVD. A prediction model consisting of integer risk scores demonstrated good discrimination (c-statistic 0.88) and goodness of fit (Hosmer-Lemeshow test P = 0.18). In a validation cohort, the model demonstrated moderate discrimination (c-statistic 0.77) and goodness of fit (Hosmer-Lemeshow test P = 0.15), suggesting external validity. CONCLUSIONS: The above-described simple model for predicting CVD after living donor KT was accurate and useful in clinical situations.

DOI： 10.1093/ndt/gfaa275

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BACKGROUND: Several large population-based studies have demonstrated that urinary salt excretion (USALT) is associated with albuminuria. However, this relationship has not been assessed in a large cohort study of patients with chronic kidney disease (CKD). Thus, the present study aimed to elucidate whether USALT was independently associated with albuminuria in a large cohort of patients with CKD. METHODS: This cross-sectional study was conducted in 4075 patients with CKD not on dialysis. USALT (g/day) was estimated from spot urine. Patients were divided into quartiles (Q1-Q4) according to estimated USALT. Multivariable regression models were used to determine whether USALT was independently related to urinary albumin-to-creatinine ratio (UACR) or the presence of macroalbuminuria. RESULTS: In multivariable linear regression analyses, 1-g/day increment in USALT was significantly associated with log UACR [coefficient 0.098, 95&#37; confidence interval (CI) 0.075-0.121]. In addition, compared with the first USALT quartile, the third and fourth quartiles exhibited significant associations with log UACR (Q3: coefficient 0.305, 95&#37; CI 0.154-0.456; Q4: coefficient 0.601, 95&#37; CI 0.447-0.756). Furthermore, multivariable logistic regression analyses showed that USALT (1-g/day increment) was significantly associated with the presence of macroalbuminuria [odds ratio (OR) 1.11, 95&#37; CI 1.07-1.14]; the third and fourth USALT quartiles exhibited significantly greater risks of macroalbuminuria, compared with the first quartile (Q3: OR 1.33, 95&#37; CI 1.09-1.62; Q4: OR 1.89, 95&#37; CI 1.54-2.32). CONCLUSIONS: This significant association of USALT with UACR and macroalbuminuria suggests that higher USALT may cause increased albuminuria, thereby contributing to kidney disease progression.

DOI： 10.1007/s10157-020-01950-4

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The prevalence of atherosclerotic diseases is higher in hemodialysis patients. The aim of the current study was to investigate associations between cholesterol level and the incidences of cardiovascular disease (CVD) and mortality in hemodialysis patients. A total of 3517 participants undergoing maintenance hemodialysis were followed up for 10 years. Total cholesterol (TC) level was divided into quartile in baseline data. The multivariate analyses were calculated by a Cox proportional hazards model. The incidences of ischemic heart disease (IHD), peripheral artery disease (PAD), and CVD were significantly positively associated with higher cholesterol levels after adjustment for confounding factors (P < 0.01, P = 0.04, and P < 0.01, respectively). Furthermore, the incidences of cancer-associated mortality and all-cause mortality were significantly positively associated with lower cholesterol levels after adjustment for confounding factors (both P < 0.01). The lowest TC level at all-cause mortality risk was 179 mg/dL. From these results, higher TC predicts IHD, PAD, and CVD events, and lower TC predicts cancer-associated mortality and all-cause mortality in patients undergoing maintenance hemodialysis.

DOI： 10.1111/1744-9987.13455

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: The utility of the Columbia classification (Col-class) for focal segmental glomerulosclerosis (FSGS) has not yet been fully proven. METHODS: We extracted 201 FSGS patients from 10 nephrology centers in Japan and investigated the difference of a composite renal endpoint, defined as doubling of serum creatinine and/or development of end-stage renal disease, in pathological variants. Sensitivity analysis was used to prove the utility of the Col-class to predict renal outcomes. Additionally, the renal protective effects of steroids and/or immunosuppression (steroid/IS) were investigated in patients stratified according to the Col-class. RESULTS: The patients were classified into the following variants: not otherwise specified [NOS; n = 121 (60.1&#37;)], perihilar [n = 31 (15.4&#37;)], cellular [n = 19 (9.5&#37;)], tip [n = 17 (8.5&#37;)] and collapsing [n = 13 (6.5&#37;)]. No tip variant patients reached the renal endpoint. The renal outcome in the collapsing variant was significantly poorer than that in the NOS [hazard ratio (HR) 3.71; P = 0.005]. In the sensitivity analysis, the area under the receiver operating characteristic curve for the renal endpoint was increased by adding Col-class to a model including common risk factors (P = 0.021). In a subgroup treated without steroid/IS, the outcome in the cellular variant was worse than that in the NOS (HR 5.10; P = 0.040) but the difference was not observed in the subgroup with steroid/IS (HR 0.54; P = 0.539). CONCLUSIONS: The Col-class is useful to predict renal prognosis in Japanese patients with FSGS. In addition to good prognosis in the tip variant and poor in the collapsing variant, good clinical course in the cellular variant treated with steroid/IS was suggested.

DOI： 10.1093/ndt/gfy374

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BACKGROUND: Parathyroid hormone (PTH) has been associated with cardiovascular disorders; however, it is unknown whether plasma PTH concentrations are associated with atrial fibrillation (AF) in patients with chronic kidney disease (CKD).Methods and Results:The present cross-sectional study analyzed baseline data of 3,384 patients registered in the Fukuoka Kidney Disease Registry Study, a Japanese multicenter prospective cohort study of patients with non-dialysis-dependent CKD. The outcome was prevalence of AF, and the main risk factor was plasma intact PTH concentration. Associations between plasma intact PTH concentration quartiles (Q1-Q4, from lowest to highest) and the presence of AF were analyzed using logistic regression. In all, 185 patients had AF; 22, 34, 59, and 70 patients were in Q1, Q2, Q3, and Q4 of PTH concentrations, respectively. The prevalence of AF increased incrementally with increases in plasma intact PTH. In the logistic regression model, patients with higher plasma intact PTH concentrations (Q2-Q4) had higher adjusted odds ratios (95&#37; confidence intervals) for the prevalence of AF relative to the reference group (Q1), namely 1.33 (0.76-2.34), 1.82 ([1.06-3.13), and 1.99 (1.08-3.64), respectively (P=0.016). CONCLUSIONS: Higher plasma intact PTH concentrations were significantly and incrementally associated with an increased prevalence of AF in non-dialysis-dependent CKD patients.

DOI： 10.1253/circj.CJ-19-1201

Language：English   Publishing type：Research paper (scientific journal)  

Objective Uremic toxins are known risk factors for cancer in patients undergoing hemodialysis (HD). Although adequate removal of uremic toxins might reduce the cancer risk by improving subclinical uremia, the relationship between the dialysis dose and risk of cancer death in patients undergoing HD remains unclear. Methods In this prospective observational study, 3,450 patients undergoing HD were followed up for 4 years. The primary outcome was cancer death. Patients were divided into quartiles according to their baseline Kt/V levels. The association between the Kt/V levels and risk of cancer death was estimated using the Kaplan-Meier method and Cox proportional-hazards model. Results A total of 111 patients (3.2&#37;) died from cancer during the 4-year observational period. The 4-year survival rate decreased linearly with decreasing Kt/V. The multivariable-adjusted hazard ratios (HRs) and 95&#37; confidence intervals (CIs) for cancer death were 2.23 (95&#37; CI, 1.13-4.56), 1.77 (0.88-3.63), and 1.89 (1.04-3.56) in quartile (Q) 1, Q2, and Q3, respectively, compared with patients in the highest Kt/V category (Q4) (p for trend = 0.06). Every 0.1 increase in Kt/V was associated with a reduction of 8&#37; in cancer death (HR 0.92, 95&#37; CI, 0.85-0.99). Conclusion A lower dialysis dose might be associated with a higher risk of cancer death in patients undergoing HD. Kt/V is a simple indicator of dialysis dose used in clinical practice and might be a useful modifiable factor for predicting the risk of cancer death. Further basic and interventional studies are needed to confirm the apparent reduction in cancer death associated with increasing the dialysis dose.

DOI： 10.2169/internalmedicine.4027-19

Language：English   Publishing type：Research paper (scientific journal)  

AIM: The incidence of sudden death and its risk factors in patients on hemodialysis remain unclear. This study aimed to clarify the incidence of sudden death and its risk factors in Japanese patients on hemodialysis. METHODS: A total of 3505 patients on hemodialysis aged ≥ 18 years were followed for 10 years. Multivariate-adjusted hazard ratio (HR) with 95&#37; confidence interval (95&#37; CI) of each risk factor of sudden death were calculated using a Cox proportional hazards model. RESULTS: During the 10-year follow-up, 1735 patients died, including 227 (13&#37;) sudden deaths. The incidence rate of sudden death was 9.13 per 1000 person-years. In multivariable-adjusted Cox analysis, male sex (HR 1.67; 95&#37; CI 1.20-2.33), age (HR 1.44; 95&#37; CI 1.26-1.65 per 10-year higher), the presence of diabetes (HR 2.45; 95&#37; CI 1.82-3.29), history of cardiovascular disease (HR 1.85; 95&#37; CI 1.38-2.46), cardiothoracic ratio (HR 1.21; 95&#37; CI 1.07-1.39 per 5&#37; higher), serum C-reactive protein (HR 1.11; 95&#37; CI 1.03-1.20 per 1-mg/dL higher), and serum phosphate (HR 1.15; 95&#37; CI 1.03-1.30 per 1-mg/dL higher) were independent predictors of sudden death. A subgroup analysis stratified by sex or age showed that lower serum corrected calcium levels, not using vitamin D receptor activators in women, and a shorter dialysis session length in men or older people (≥ 65 years) increased the risk for sudden death. CONCLUSIONS: This study clarified the incidence of sudden death and its specific predictors in Japanese patients on hemodialysis.

DOI： 10.5551/jat.49833

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Renin-angiotensin system blockers (RASBs) reduce end-stage kidney disease and cardiovascular event (CVE) development in chronic kidney disease. However, whether RASBs improve long-term prognosis in kidney transplant (KT) recipients remain unknown. METHOD: We investigated 900 kidney transplant patients in a multicenter retrospective cohort study in Japan and compared death-censored graft survival and CVE (total, cardiac events, stroke) based on RASB use within 12 months after KT. The associations were examined using a Cox hazard model and propensity score-matching analysis. RESULTS: The cohort comprised 375 patients treated with RASBs (RASB group) and 525 patients without RASBs (control group). The median observational period was 82 months, with 68 patients reaching graft loss: 79 total CVE, 36 cardiac events, 26 stroke. In a matching cohort comprising 582 patients, death-censored graft survival, total CVE, and cardiac events were not different between the two groups. Only stroke incidence rate was significantly lower in the RASB group compared with the control group (1.4 vs. 6.4 per 1000 patients/year, log-ranked P = 0.005). In a multivariable analysis, stroke events were also significantly lower in the RASB group compared with the control group (Hazard ratio and 95&#37; confidence interval, 0.20 [0.04-0.62]). CONCLUSION: Thus, RASBs potentially reduce stroke events in KT recipients.

DOI： 10.1007/s10157-019-01827-1

Language：English   Publishing type：Research paper (scientific journal)  

Bilirubin is recognized as an endogenous antioxidant, and low serum bilirubin is reported to be associated with the progression of kidney disease. However, it is unclear whether serum bilirubin levels are associated with the loss of residual kidney function (RKF) in peritoneal dialysis (PD) patients. This study investigated the relationship between serum total bilirubin and loss of RKF. We prospectively followed 94 PD patients who started PD in our hospital between June 2006 and May 2016. Ten patients who had chronic liver disease or cirrhosis were excluded. Patients were divided into three groups based on serum total bilirubin concentration tertiles: tertile 1 (T1) < 0.3, T2 = 0.3, and T3 ≥ 0.4 mg/dL. We estimated the relationship between serum bilirubin and loss of RKF, defined as daily urine volume (<100 mL) within 3 years after starting PD, using a Cox proportional hazards model. During the 3-year observation period, 22 patients lost RKF. The incidence rate of loss of RKF increased linearly with the decrease in serum total bilirubin levels (P for trend < 0.05). After adjusting for confounding factors, low serum total bilirubin level was shown to be an independent predictor of loss of RKF (hazard ratio [HR] for every 0.1 mg/dL decrease, 1.50; 95&#37; confidence interval [CI], 1.01-2.51; HR [95&#37;CI] for T2 and T1 [vs. T3] 2.03 [0.65-7.88] and 3.70 [1.00-15.9]). This study suggests that low serum total bilirubin levels are associated with the loss of RKF in PD patients.

DOI： 10.1111/1744-9987.12865

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation. METHODS: We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m2 at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort). RESULTS: In the derivation cohort, 89 patients (25.9&#37;) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy. CONCLUSIONS: This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

DOI： 10.1007/s10157-019-01774-x

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Graft biopsy is the gold standard for diagnosis of BK polyomavirus-associated nephropathy (BKPyVAN), and polymerase chain reaction is the most specific screening technique. Development of a noninvasive, cost-effective marker for BKPyVAN is important. METHODS: We reviewed 492 adult kidney transplant patients. We investigated peripheral blood lymphocyte (PBL) count and urinary cytology at graft biopsy in patients with BKVPyAN (n = 21), acute T-cell-mediated rejection (n = 79), and no evidence of acute rejection (n = 149). We performed univariate and multivariate logistic regression and receiver operating characteristics analyses to compare the test performance of PBL count, urinary cytology, and their combination for diagnosis of BKPyVAN. RESULTS: The PBL count at biopsy was significantly lower in the BKPyVAN group than the acute T-cell-mediated rejection and no acute rejection groups (959 ± 290/μL, 1433 ± 673/μL, and 1531 ± 549/μL, respectively; P < .01). The PBL count was 959 ± 290/μL at diagnosis of BKPyVAN and increased to 1123 ± 377/μL, 1238 ± 419/μL, and 1292 ± 491/μL at 1, 2, and 3 months after treatment, respectively (P < .05). On univariate analysis, the area under the curve was significantly higher for the combined model than for PBL and cytology alone (0.930, 0.797, and 0.875, respectively; P < .01). The improved test performance in the combined model remained significant after multivariate adjustment (0.972, 0.844, and 0.928, respectively; P < .01). CONCLUSIONS: Decreased PBL count was found in BKPyVAN, and the predictive performance of the combination of PBL count and urinary cytology was significantly enhanced for diagnosis of BKPyVAN.

DOI： 10.1016/j.transproceed.2019.01.129

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BACKGROUND: Assessment of infection-related mortality remains inadequate in patients undergoing peritoneal dialysis. This study was performed to develop a risk model for predicting the 2-year infection-related mortality risk in patients undergoing peritoneal dialysis. METHODS: The study cohort comprised 606 patients who started and continued peritoneal dialysis for 90 at least days and was drawn from the Fukuoka Peritoneal Dialysis Database Registry Study in Japan. The patients were registered from 1 January 2006 to 31 December 2016 and followed up until 31 December 2017. To generate a prediction rule, the score for each variable was weighted by the regression coefficients calculated using a Cox proportional hazard model adjusted by risk factors for infection-related mortality, including patient characteristics, comorbidities, and laboratory data. RESULTS: During the follow-up period (median, 2.2 years), 138 patients died; 58 of them of infectious disease. The final model for infection-related mortality comprises six factors: age, sex, serum albumin, serum creatinine, total cholesterol, and weekly renal Kt/V. The incidence of infection-related mortality increased linearly with increasing total risk score (P for trend <0.001). Furthermore, the prediction model showed adequate discrimination (c-statistic = 0.79 [0.72-0.86]) and calibration (Hosmer-Lemeshow test, P = 0.47). CONCLUSION: In this study, we developed a new model using clinical measures for predicting infection-related mortality in patients undergoing peritoneal dialysis.

DOI： 10.1371/journal.pone.0213922

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Background: Residual kidney function (RKF) is an important factor influencing both technique and patient survival in peritoneal dialysis (PD) patients. B-type natriuretic peptide (BNP) is considered a marker of cardio-renal syndrome. The relationship between BNP and RKF in PD patients remains unclear.Methods: We conducted a prospective study of 89 patients who had started and continued PD for 6 months or more in Kyushu University Hospital between June 2006 and September 2015. Participants were divided into low BNP (<= 102.1 ng/L) and high BNP (> 102.1 ng/L) groups according to median plasma BNP level at PD initiation. The primary outcome was RKF loss, defined as 24-hour urine volume less than 100 mL. We estimated the association between BNP and RKF loss using a Kaplan-Meier method and Cox proportional hazards model and compared the rate of RKF decline between the 2 groups. To evaluate the consistency of the association, we performed subgroup analysis stratified by baseline characteristics.Results: During the median follow-up of 30 months, 30 patients lost RKF. Participants in the high BNP group had a 5.87-fold increased risk for RKF loss compared with the low BNP group after adjustment for clinical and cardiac parameters. A high plasma BNP level was more clearly associated with RKF loss in younger participants compared with older participants in subgroup analysis.Conclusions: B-type natriuretic peptide may be a useful risk marker for RKF loss in PD patients. The clinical importance of plasma BNP level as a marker of RKF loss might be affected by age.

DOI： 10.3747/pdi.2017.00241

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BACKGROUND & AIMS: The geriatric nutritional risk index (GNRI) is a simple but useful nutritional marker for all-cause mortality and cardiovascular mortality in patients undergoing hemodialysis (HD). However, whether the GNRI can predict infection-related mortality in patients undergoing HD remains unclear, and there is insufficient evidence regarding whether the GNRI improves the predictive value for risk assessment beyond the existing conventional nutritional markers. Here, we investigated the association between the GNRI and infection-related mortality in patients undergoing HD and evaluated the predictive value of GNRI. METHODS: A prospective cohort study was performed on a total of 3436 Japanese HD patients aged ≥18 years. Patients were divided into four groups by quartiles of GNRI: (Quartile 1 [Q1], >100.2; Q2, 95.9-100.2; Q3, 90.8-95.8; Q4, <90.8). We estimated the relationship between GNRI and all-cause mortality and infection-related mortality using a Cox proportional hazards model. To assess the additional predictive value of the GNRI in risk assessment, we compared the c-statistic, net reclassification improvement, and integrated discrimination improvement among serum albumin, serum creatinine, and the GNRI. RESULTS: During follow-up period (median, 4.0 years), a total of 564 patients died; 120 of these patients died of infectious disease. All-cause mortality and infection-related mortality increased linearly with lower GNRI levels. After adjusting for confounding risk factors, the GNRI was an independent predictor of infection-related mortality as well as all-cause mortality (hazard ratio [HR], 5.89; 95&#37; confidence interval [CI], 2.85-13.8; P < 0.001 for Q4 vs. Q1, HR, 2.62; 95&#37; CI, 1.23-6.24; P = 0.01 for Q3 vs. Q1). Additionally, when the GNRI was incorporated into a model with potential risk factors instead of serum albumin, the c-statistic increased significantly (0.811 vs. 0.821, P = 0.03), and the net reclassification improvement and integrated discrimination improvement was 0.26 (P = 0.005) and 0.005 (P = 0.01). This association was more apparent in the older patients (0.739 vs. 0.760, P = 0.02) than in the younger patients (0.916 vs. 0.912, P = 0.35). Similar results were observed between serum creatinine and the GNRI, but the difference did not reach statistical significance. CONCLUSIONS: Lower GNRI levels are an independent risk factor for infection-related mortality in patients undergoing HD. Moreover, addition of the GNRI to models with standard risk factors significantly improves the predictive ability of infection-related mortality, especially in older patients.

DOI： 10.1016/j.clnu.2018.01.019

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The influence of pre-dialysis blood pressure (BP) on the prognosis of hemodialysis (HD) patients is still inconclusive.A total of 3436 HD patients were prospectively followed up for 4 years. The patients were divided into quintiles of pre-dialysis systolic BP (SBP) and diastolic BP (DBP) levels [mm Hg]: Quintile 1 (Q1), SBP <134, DBP <66; Q2, SBP 134 to 147, DBP 66 to 72; Q3, SBP 148 to 158, DBP 73 to 79; Q4, SBP 159 to 171, DBP 80 to 85; Q5, SBP ≥172, DBP ≥86. The association between the pre-dialysis BP and outcomes were examined using a Cox proportional hazards model.During a 4-year follow-up period, 564 (16.4&#37;) patients died of any cause and 590 (17.2&#37;) developed cardiovascular (CV) events. The lowest level of pre-dialysis SBP group (Q1) showed a significantly increased risk of all-cause mortality (hazard ratio [HR] 1.83, 95&#37; confidence interval [CI] 1.40-2.39) and the highest group (Q5) significantly increased risk of CV events (HR 1.31, 95&#37; CI 1.02-1.68) compared with the reference group (Q3), respectively. The highest level of pre-dialysis DBP group was significantly associated with increased risk for both all-cause mortality and CV events. Restricted cubic spline analysis for BP and outcomes suggested the optimal pre-dialysis BP value associated with the lowest risk of outcomes was SBP 152 mm Hg for all-cause mortality, SBP 143 mm Hg for CV events, and DBP 68 mm Hg for all-cause mortality.Our results suggested that pre-dialysis BP was independently associated with all-cause mortality and CV events among Japanese HD patients.

DOI： 10.1097/MD.0000000000013485

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OBJECTIVES: Hemodialysis (HD) time has been recognized as an important factor in dialysis adequacy. However, few studies have reported on associations between HD time and prognosis among maintenance HD patients. We present some findings from a prospective cohort study, the -Q-Cohort Study, which was set up to explore risk factors for mortality in Japanese HD patients. We hypothesized that HD ≥5 h was associated with a significant survival advantage compared with HD < 5 h. The present study examined association between HD time and mortality in Japanese HD patients. METHODS: The prospective multicenter Q-Cohort Study was conducted between December 2006 and December 2010, following 3,456 Japanese HD patients for 4 years. We examined the association between HD time and prognosis using Cox proportional hazards modeling. Propensity scores were calculated using logistic regression. RESULTS: During follow-up, 566 patients died from any cause. Patients with HD ≥5 h (n = 2,141) showed -significantly lower risk of all-cause death (hazards ratio = 0.82; 95&#37; CI 0.68-0.99) than those with HD < 5 h (n = 1,315), after adjusting for confounding risk factors. This -association remained significant using a propensity score-based approach. After stratifying the analysis by patient age in 10-year increments, this finding remained -significant only in patients who were ≥80 years of age. CONCLUSION: Our results suggest that HD ≥5 h has a more favorable effect on mortality than HD < 5 h.

DOI： 10.1159/000489680

Language：English   Publishing type：Research paper (scientific journal)  

Background: The contribution of the hemoglobin concentration to the incidence of hemorrhagic or ischemic stroke in patients undergoing hemodialysis is unclear. Methods: In total, 3436 patients undergoing prevalent hemodialysis were followed up for 4 years. The primary outcome was the first development of hemorrhagic or ischemic stroke. The baseline hemoglobin concentration was divided into quartiles [hemoglobin (g/dL): Q1, ≤9.7; Q2, 9.8-10.5; Q3, 10.6-11.1; Q4, ≥11.2]. The association between the hemoglobin concentration and each type of stroke was examined using the Kaplan-Meier method and a Cox proportional hazards model. Results: During the follow-up period, 76 (2.2&#37;) patients developed hemorrhagic stroke and 139 (4.0&#37;) developed ischemic stroke. The 4-year incidence rate of hemorrhagic stroke was significantly higher in patients with lower hemoglobin concentrations. Compared with the quartile of patients with the highest hemoglobin concentrations (Q4), the multivariable-adjusted hazard ratios for hemorrhagic stroke were 1.18 (95&#37; confidence interval, 0.56-2.51), 1.59 (0.82-3.21) and 2.31 (1.16-4.73) in patients in Q3, Q2 and Q1, respectively. No association was identified between the 4-year incidence rate of ischemic stroke and the hemoglobin concentration. Compared with the quartile of patients with the lowest hemoglobin concentrations (Q1), the multivariable-adjusted hazard ratios for ischemic stroke were 1.17 (95&#37; confidence interval, 0.73-1.89), 0.88 (0.51-1.51) and 1.10 (0.66-1.83) in patients in Q2, Q3 and Q4, respectively. Conclusions: Our results suggest that low hemoglobin concentrations are associated with a high risk of hemorrhagic stroke, but not of ischemic stroke, in patients undergoing hemodialysis.

DOI： 10.1093/ndt/gfx305

Language：English   Publishing type：Research paper (scientific journal)  

Serum albumin is the major intravascular antioxidant. Though oxidative stress plays an important role in the pathophysiology of Immunoglobulin A nephropathy (IgAN), the association between serum albumin and the progression of IgAN is not entirely understood. This retrospective cohort study of 1,352 participants with biopsy-proven IgAN determined the associations between serum albumin level and the incidence of end-stage renal disease (ESRD) using a Cox proportional hazards model. Patients were divided into three groups by tertiles of serum albumin level: Low, Middle, and High group (≤3.9 g/dL, 4.0-4.3 g/dL, ≥4.4 g/dL, respectively). During the median 5.1-year follow-up period, 152 patients (11.2&#37;) developed ESRD. Participants in the Low group had a 1.88-fold increased risk for ESRD compared with those in the High group after adjustment for clinical parameters, including urinary protein excretion, and pathological parameters (Oxford classification). We also experimentally proved the antioxidant capacity of albumin on mesangial cells. The intracellular reactive oxygen species and mitochondrial injury, induced by hydrogen peroxide were significantly attenuated in albumin-pretreated mouse mesangial cells and human kidney cells compared with γ-globulin-pretreated cells. Low serum albumin level is an independent risk factor for ESRD in patients with IgAN. The mechanism could be explained by the antioxidant capacity of serum albumin.

DOI： 10.1371/journal.pone.0196655

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND AND AIMS: Recent studies have reported an association between serum uric acid (SUA) and renal arteriolar changes in patients with chronic kidney disease (CKD). However, the association in individuals without CKD remains unclear. In this study, we investigated the relationship between SUA and renal arteriolar lesions in individuals without CKD from our living kidney donor cohort. METHODS: Between January 2006 and May 2016, 393 living kidney donors underwent "time-zero" biopsy at Kyushu University Hospital. Patients were divided into sex-specific quartiles of SUA before donation: Q1, Q2, Q3, and Q4 (male: <5.2,5.2-5.8,5.9-6.4, and ≥6.5 mg/dL, female: <3.8,3.8-4.3,4.4-5.0, and ≥5.1 mg/dL). Renal arteriolar hyalinization and wall thickening were assessed using a semiquantitative grading system. Predictive performance was compared between models with and without SUA by calculating the net reclassification improvement (NRI). RESULTS: In total, 158 (40.2&#37;) patients had arteriolar hyalinization, and 148 (37.6&#37;) had wall thickening. High SUA was significantly associated with arteriolar hyalinization in multivariable logistic analysis (odds ratio [OR] per 1-mg/dL increase in SUA, 1.24; 95&#37; confidence interval [CI], 1.00-1.53; p = 0.048. OR for Q4 vs. Q2, 2.22; 95&#37; CI, 1.17-4.21; p = 0.01). We found no association between SUA and wall thickening. When SUA was incorporated into a predictive model with conventional atherosclerotic factors, the NRI was 0.21 (p = 0.04). CONCLUSIONS: High SUA was an independent risk factor for arteriolar hyalinization in individuals without CKD. SUA provided additional predictive value beyond conventional atherosclerotic factors in predicting arteriolar hyalinization.

DOI： 10.1016/j.atherosclerosis.2017.09.017

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Differences in the predictive value of daytime systolic blood pressure (SBP) and night-time SBP by ambulatory blood pressure monitoring on renal outcomes have not been fully investigated in chronic kidney disease (CKD) patients. This study compared the prognostic value between daytime and night-time SBP on renal outcomes in CKD.Methods and Results:This prospective observational study included 421 patients. The composite renal endpoint was endstage renal disease (ESRD) or death. Cox models were used to determine associations of daytime and night-time SBP with renal outcomes. There were 150 renal events (ESRD, 130; death, 20). Multivariable Cox analyses demonstrated that hazard ratios (HRs) [95&#37; confidence interval (CI)] for composite renal outcomes of every 10-mmHg increase in daytime and night-time SBP levels were 1.13 (1.02-1.26) (P=0.02) and 1.15 (1.05-1.27) (P<0.01), respectively. In addition, compared with the 1st daytime or night-time SBP quartile, HRs (95&#37; CI) for outcomes in the 2nd, 3rd, and 4th quartiles were: daytime SBP, 1.25 (0.70-2.25), 1.09 (0.61-1.94), and 1.58 (0.88-2.85; P=0.13) (P for trend=0.16); night-time SBP, 1.09 (0.61-1.96), 1.31 (0.76-2.28), and 1.82 (1.00-3.30; P=0.049) (P for trend=0.03), respectively. CONCLUSIONS: Night-time SBP appeared superior to daytime SBP for predicting renal outcomes in this population of patients.

DOI： 10.1253/circj.CJ-17-0063

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Cardiothoracic ratio by chest radiography is commonly used to assess volume status. Little is known about the relationships between cardiothoracic ratio and the incidence of clinical outcomes in patients undergoing hemodialysis (HD). STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 3,436 participants in the Q-Cohort Study 18 years or older who underwent maintenance HD in Japan. PREDICTOR: Cardiothoracic ratio. OUTCOMES & MEASUREMENTS: All-cause mortality and cardiovascular disease (CVD) events. RESULTS: During a 4-year follow-up period, 564 (16.4&#37;) patients died of any cause and 590 (17.2&#37;) developed CVD events. From baseline cardiothoracic ratios, participants were categorized into sex-specific quartiles because cardiothoracic ratio distribution differed by sex. The 4-year event-free survival rate, in terms of all-cause mortality and CVD events, was significantly lower with higher cardiothoracic ratios. Compared to the lowest cardiothoracic ratio (quartile 1), multivariable-adjusted HRs for all-cause mortality were 0.89 (95&#37; CI, 0.66-1.20), 1.41 (1.08-1.86), and 1.52 (1.17-2.00) in patients from quartiles 2, 3, and 4, respectively. Similarly, in comparison to quartile 1, multivariable-adjusted HRs for CVD events were 1.00 (95&#37; CI, 0.77-1.31), 1.18 (0.92-1.53), and 1.37 (1.07-1.76) in patients from quartiles 2, 3, and 4, respectively. Furthermore, the combination of higher cardiothoracic ratio and normohypotension (systolic blood pressure < 140mmHg and diastolic blood pressure < 90mmHg) was associated with higher risk for CVD events. LIMITATIONS: Single measurement of all variables, potentially less-heterogeneous patient population, and limited ascertainment of cardiac parameters and the outcomes. CONCLUSIONS: Higher cardiothoracic ratio is associated with higher risk for both all-cause mortality and CVD events in patients undergoing HD.

DOI： 10.1053/j.ajkd.2016.11.026

Language：English   Publishing type：Research paper (scientific journal)  

Recently, low serum uric acid (SUA) levels and high SUA levels, have emerged as risk factors for cardiovascular disease, as well as for the incidence of acute kidney injury and chronic kidney disease (CKD). However, the effect of low SUA on the progression of CKD remains unclear. To evaluate the association between SUA and renal prognosis in patients with immunoglobulin A nephropathy (IgAN), one of the most common causes of CKD, we retrospectively followed 1218 patients who were diagnosed with primary IgAN by kidney biopsy between October 1979 and December 2010. Patients were divided into three groups on the basis of SUA level tertiles: low (L group), middle (M group) and high (H group) tertiles (<6.1, 6.1-7.0, and >7.0 mg dl-1, respectively, for men and <4.4, 4.4-5.3, and >5.3 mg dl-1, respectively, for women). The risk factors for developing end-stage renal disease (ESRD) were estimated using a Cox proportional hazards model. After a median follow-up of 5.1 years, 142 patients (11.7&#37;) developed ESRD. The hazard ratio (95&#37; confidence interval) showed a J-shaped trend with the tertiles in both men (1.18 (0.55-2.54), 1.00 (reference), and 1.80 (1.01-3.10) in L, M and H groups, respectively) and women (2.73 (1.10-6.76), 1.00 (reference) and 2.49 (1.16-5.34) in L, M and H groups, respectively). Notably, low SUA was significantly associated with incident ESRD in women. This finding suggests that SUA has a J-shaped association with ESRD in patients with IgAN, especially women.

DOI： 10.1038/hr.2016.134

Language：English   Publishing type：Research paper (scientific journal)  

OBJECTIVE: In patients with preserved kidney function, a positive association of fibroblast growth factor 23 (FGF23) with serum uric acid (SUA) has been reported; however, the relationship in overall chronic kidney disease (CKD) patients has not been investigated. No report has examined the relationship between FGF23 and uric acid clearance (CUA). The aim of the present study was to determine whether FGF23 is independently associated with urate metabolism in patients with CKD stages 1-5. MATERIALS AND METHODS: In this cross-sectional study, 537 CKD patients were enrolled. SUA, CUA, FGF23, parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D (1,25(OH)2D) were measured. Multivariable linear regression analysis was applied to determine independent factors associated with SUA or CUA. RESULTS: In all patients, both SUA and CUA were independently associated with male sex, use of diuretics, use of uric acid-lowering agents, estimated glomerular filtration rate, and log FGF23 (β=0.29, P<0.01 for SUA; β=-0.11, P<0.01 for CUA), but not with log PTH or log 1,25(OH)2D. Dyslipidemia and diabetes were also independent factors for SUA and CUA, respectively. In multivariable analyses by sex, log FGF23 was associated with SUA in both sexes (β=0.32, P<0.01 in males vs. β=0.20, P=0.02 in females). Conversely, log FGF23 was independently associated with CUA in males (β=-0.15, P<0.01), but not in females (β=-0.09, P=0.17). CONCLUSIONS: FGF23 was independently associated with urate metabolism in this population of CKD patients. FGF23 might also have a stronger association with urate metabolism in males compared with females.

DOI： 10.1016/j.metabol.2016.07.005

Language：English   Publishing type：Research paper (scientific journal)  

Tuberculosis is one of the common causes of fever of unknown origin in patients with chronic kidney disease (CKD). Extrapulmonary tuberculosis is more common in CKD patients, and is, unfortunately, often underdiagnosed despite extensive assessments. Recently, fluorine-18-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has been available in the diagnosis of malignancy, inflammatory and infectious diseases, and has become a useful diagnostic tool. Here, we present two cases of endstage kidney disease who presented with fever of unknown origin at the time of dialysis initiation. In both cases, although interferon-gamma-releasing assay was positive, combined conventional diagnostic modalities such as computed tomography and gallium-citrate scintigraphy failed to detect the sites infected with tuberculosis. By contrast, extrapulmonary lesions were detected by FDG-PET/CT and successfully treated with combined anti-tuberculous drugs. Diagnosis of extrapulmonary tuberculosis was confirmed by biopsy of the affected lymph node and lumbar spine, followed by PCR of the biopsied specimen. These cases highlight the importance of considering tuberculosis as one of the differential diagnoses in pre-dialysis CKD patients with persistent fever, and the usefulness of FDG-PET/CT in the detection of infectious sites of extrapulmonary tuberculosis.

DOI： 10.1007/s13730-015-0181-2

Language：English   Publishing type：Research paper (scientific journal)  

Extended catheters with an upper abdominal exit-site (UAE) are reportedly associated with a lower incidence of peritoneal dialysis (PD)-related infections. However, little information about the optimal peritoneal catheter configuration for UAE is available. In this nonrandomized multicenter trial, 147 consecutive cases of a UAE involving either a conventional straight (CS; 80 cases) or extended swan-neck catheter (SN; 67 cases) were analyzed to compare exit-site and tunnel infections (ESTI), peritonitis, and catheter survival. The ESTI-free and catheter survival rates were significantly lower in the SN than in the CS group (P <0.01). However, the peritonitis-free survival rate was not different (P = 0.26). In terms of analyses for infection rates, fewer episodes of ESTI (1.284 vs 0.608 episodes/patient-year; P <0.01) and peritonitis (0.345 vs 0.152 episodes/patient-year; P = 0.06) were observed in the SN than CS group. Recurrence analyses showed that the mean number of cumulative episodes of ESTI and peritonitis between two groups were significantly different.

DOI： 10.1111/1744-9987.12358

Language：English   Publishing type：Research paper (scientific journal)  

Urinary protein (UP) is widely used as a clinical marker for podocyte injury; however, not all proteinuric nephropathies fit this model. We previously described the elevation of urinary angiotensinogen (AGT) accompanied by AGT expression by injured podocytes in a nitric oxide inhibition rat model (Eriguchi M, Tsuruya K, Haruyama N, Yamada S, Tanaka S, Suehiro T, Noguchi H, Masutani K, Torisu K, Kitazono T. Kidney Int 87: 116-127, 2015). In this report, we performed the human and animal studies to examine the significance and origin of urinary AGT. In the human study, focal segmental glomerulosclerosis (FSGS) patients presented with higher levels of urinary AGT, corrected by UP, than minimal-change disease (MCD) patients. Furthermore, AGT was evident in podocin-negative glomerular segmental lesions. We also tested two different nephrotic models induced by puromycin aminonucleoside in Wistar rats. The urinary AGT/UP ratio and AGT protein and mRNA expression in sieved glomeruli from FSGS rats were significantly higher than in MCD rats. The presence of AGT at injured podocytes in FSGS rats was detected by immunohistochemistry and immunoelectron microscopy. Finally, we observed the renal tissue and urinary metabolism of exogenous injected human recombinant AGT (which is not cleaved by rodent renin) in FSGS and control rats. Significant amounts of human AGT were detected in the urine of FSGS rats, but not of control rats. Immunostaining for rat and human AGT identified that only rat AGT was detected in injured podocytes, and filtered human AGT was seen in superficial proximal tubules, but not in injured podocytes, suggesting AGT generation by injured podocytes. In conclusion, the urinary AGT/UP ratio represents a novel specific marker of podocyte injury.

DOI： 10.1152/ajprenal.00260.2015

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: IgG4-related disease is a novel disease entity characterized by elevated serum IgG4 and tissue infiltration by IgG4-positive plasma cells. Typical renal pathology is tubulointerstitial nephritis with storiform fibrosis, although the co-existence of various glomerular lesions has been described. Here, we present the first report of a case of IgG4-related kidney disease and membranoproliferative glomerulonephritis showing the discrepancy in IgG subclasses between the kidney interstitium and glomeruli. CASE PRESENTATION: A 70-year-old Japanese woman was diagnosed with membranoproliferative glomerulonephritis and focal tubulointerstitial nephritis with IgG4-positive plasma cells. Immunofluorescence studies revealed predominant deposition of IgG3 and IgG2, but not IgG4 in the glomeruli. We administered oral prednisolone at 30 mg/day, and the abnormalities in urine and blood tests gradually resolved. CONCLUSION: In this case, different patterns of IgG subclasses detected in the glomeruli and interstitial plasma cells suggest overlapping immunologic abnormalities. The favorable clinical course in our patient suggests that steroid therapy is promising in cases of IgG4-related kidney disease accompanied by glomerulonephritis.

DOI： 10.1186/s12882-015-0164-8

Language：English   Publishing type：Research paper (scientific journal)  

OBJECTIVE: Serum bilirubin has been reported to be associated with the progression of kidney disease in patients with diabetic nephropathy. Less is known, however, about the relationship between bilirubin and chronic kidney disease (CKD) of other etiologies. This study was designed to clarify whether serum total bilirubin concentration is associated with kidney disease progression in patients with CKD independent of etiology. MATERIALS AND METHODS: This prospective observational study enrolled 279 consecutive patients with stages 3-5 CKD. The renal endpoint was the composite of the doubling of serum creatinine or end-stage renal disease requiring dialysis. Patients were divided into three groups by their serum total bilirubin concentrations: ≤0.3 (lowest), 0.4-0.5 (middle), and ≥0.6 (highest) mg/dL. A Cox proportional hazards model was applied to determine the risk factors for poor renal outcome. RESULTS: The median follow-up period was 21months. One-hundred and three patients reached renal end points. After multivariable adjustment, a 0.1mg/dL increase in serum bilirubin was associated negatively with poor renal outcome (hazard ratio [HR], 0.73; 95&#37; confidence interval [CI], 0.60-0.87). In addition, after adjustment for confounding factors, including traditional and nontraditional cardiovascular risk factors, the middle (HR 3.14, 95&#37; CI 1.36-8.57) and lowest (HR 4.22, 95&#37; CI 1.81-11.59) bilirubin groups had significantly higher HRs for renal outcome than the highest bilirubin group. CONCLUSIONS: Lower serum bilirubin concentration was independently associated with adverse renal outcomes, suggesting that the measurement of serum bilirubin is useful for predicting kidney disease progression in patients with moderate to severe CKD.

DOI： 10.1016/j.metabol.2015.06.006

Language：English   Publishing type：Research paper (scientific journal)  

Fibroblast growth factor (FGF) 23 plays an important role in regulation of renal phosphate excretion in patients with chronic kidney disease. However, it remains undetermined whether FGF23 is closely linked to renal phosphate handling in patients with low glomerular filtration rate (GFR). The present cross-sectional study included 52 outpatients undergoing peritoneal dialysis with urine volume ≥ 100 mL/day. The primary outcome was level of urinary phosphate excretion, and the secondary outcomes were tubular maximal reabsorption of phosphate normalized to GFR (TmP/GFR), an index of the renal threshold for phosphate excretion, and level of peritoneal phosphate excretion. Variates of interest were serum FGF23 and parathyroid hormone (PTH) levels. The median and interquartile range of serum FGF23 level, TmP/GFR, and total urinary and peritoneal phosphate excretion were 5610 (1493-11 430) ng/mL, 1.30 (0.44-1.86) mg/dL, 117 (40-234) mg/day, and 208 (156-250) mg/day, respectively. Multivariate linear regression analysis revealed that serum FGF23 level was significantly (P < 0.05) associated with TmP/GFR negatively and significantly (P < 0.05) associated with urinary phosphate excretion positively, even after adjusting for confounders. In contrast, none of the three outcome variates was associated with serum PTH level. Neither serum FGF23 nor PTH level was associated with peritoneal phosphate excretion. The present study indicates that FGF23, but not PTH, is involved in urinary phosphate regulation, even in patients on peritoneal dialysis with residual renal function.

DOI： 10.1111/1744-9987.12221

Language：English   Publishing type：Research paper (scientific journal)  

We elucidate the underlying mechanisms of bidirectional cardiorenal interaction, focusing on the sympathetic nerve driving disruption of the local renin-angiotensin system (RAS). A rat model of N(ω)-nitro-L-arginine methyl ester (L-NAME; a nitric oxide synthase inhibitor) administration was used to induce damage in the heart and kidney, similar to cardiorenal syndrome. L-NAME induced sympathetic nerve-RAS overactivity and cardiorenal injury accompanied by local RAS elevations. These were suppressed by bilateral renal denervation, but not by hydralazine treatment, despite the blood pressure being kept the same between the two groups. Although L-NAME induced angiotensinogen (AGT) protein augmentation in both organs, AGT mRNA decreased in the kidney and increased in the heart in a contradictory manner. Immunostaining for AGT suggested that renal denervation suppressed AGT onsite generation from activated resident macrophages of the heart and circulating AGT excretion from glomeruli of the kidney. We also examined rats treated with L-NAME plus unilateral denervation to confirm direct sympathetic regulation of intrarenal RAS. The levels of urinary AGT and renal angiotensin II content and the degrees of renal injury from denervated kidneys were less than those from contralateral innervated kidneys within the same rats. Thus, renal denervation has blood pressure-independent beneficial effects associated with local RAS inhibition.

DOI： 10.1038/ki.2014.220

Language：English   Publishing type：Research paper (scientific journal)  

It is unknown whether the use of diuretics is optimal over other antihypertensive agents in patients with chronic kidney disease (CKD) whose blood pressure remains uncontrolled despite treatment with renin-angiotensin system (RAS) inhibitors. In this study, we assessed the additive effects of hydrochlorothiazide (HCTZ) on reducing proteinuria in CKD patients under treatment with losartan (LS). We conducted a multicenter, open-labeled, randomized trial. One hundred and two CKD patients with hypertension and overt proteinuria were recruited from nine centers and randomly assigned to receive either LS (50 mg, n=51) or a combination of LS (50 mg per day) and HCTZ (12.5 mg per day) (LS/HCTZ, n=51). The primary outcome was a decrease in the urinary protein-to-creatinine ratio (UPCR). The target blood pressure was <130/80 mm Hg, and antihypertensive agents (other than RAS inhibitors and diuretics) were added if the target was not attained. Baseline characteristics of the two groups were similar. After 12 months of treatment, decreases in the UPCR were significantly greater in the LS/HCTZ group than in the LS group. There were no significant differences in blood pressure or the estimated glomerular filtration rate between the two groups. LS/HCTZ led to a greater reduction in proteinuria than treatment with LS, even though blood pressure in the LS group was similar to that in the LS/HCTZ group following the administration of additive antihypertensive agents throughout the observation period. This finding suggests that LS/HCTZ exerts renoprotective effects through a mechanism independent of blood pressure reduction.

DOI： 10.1038/hr.2014.110

Language：English   Publishing type：Research paper (scientific journal)  

Fibroblast growth factor 23 (FGF23) levels in dialysis patients are influenced by various factors, including phosphorus load. However, the clinical parameters that determine serum FGF23 levels in patients on peritoneal dialysis (PD) remain unclear. The aim of the present study was to examine the effects of clinical factors, on serum FGF23 levels, with an emphasis on residual renal function (RRF). This cross-sectional study included 56 outpatients undergoing PD therapy. Urine volume ≥ 100 mL/day or renal creatinine (Cr) clearance was used as a surrogate marker for RRF. Clinical characteristics were compared between patients with and without RRF. Linear regression analysis was conducted with serum FGF23 level as the dependent variable and renal Cr clearance as the main independent variable. The median and interquartile range of serum FGF23 levels were 5970 (1451-11,688) pg/mL. Patients with RRF showed higher urinary and total phosphate eliminations, and lower serum FGF23 and phosphate levels than patients without RRF. Multivariate linear regression analysis showed that the renal Cr clearance and serum phosphate and dialysis history were negatively associated with serum FGF23 levels, even after adjusting for potential confounders including peritoneal Cr clearance. Further, the predictabilities of serum FGF23 were comparable among renal Cr clearance, Kt/V for urea, and renal phosphate clearance. RRF determined by renal Cr clearance or residual urine volume is an independent negative determinant of serum FGF23 levels in PD patients.

DOI： 10.1111/1744-9987.12170

Language：English   Publishing type：Research paper (scientific journal)  

OBJECTIVES: Serum tartrate-resistant acid phosphatase 5b (TRACP5b) is a bone resorption marker used in the assessment of bone metabolic status. The present study was designed to determine the clinical characteristics and utility of measuring serum TRACP5b levels in peritoneal dialysis (PD) patients. DESIGN: Cross-sectional study. PATIENTS: Forty-one patients receiving PD treatment in a single centre. MEASUREMENT: Serum levels of the bone turnover markers TRACP5b, N-terminal cross-linking telopeptide of type 1 collagen (NTX), bone-specific alkaline phosphatase (BAP), and parathyroid hormone (PTH) were simultaneously measured. The correlation of serum TRACP5b with other established bone markers was analysed after logarithmic transformation. Multivariate linear regression analysis was performed to examine the effects of both renal and peritoneal Kt/V (an index for solute clearance) for urea on bone markers using age, sex, body mass index, and PTH as covariates. Bone markers were also measured in three patients before and after treatment with cinacalcet hydrochloride, alphacalcidol, and raloxifene hydrochloride. RESULTS: Log TRACP5b was significantly correlated with log NTX, log BAP and log PTH. In the multivariate analysis, peritoneal Kt/V was not correlated with log NTX, log BAP or log TRACP5b. In contrast, renal Kt/V was significantly correlated with log NTX only. Responses to drug treatment were more accurately determined from serum TRACP5b and BAP than from serum NTX. CONCLUSIONS: Serum TRACP5b and BAP are potentially useful biomarkers for the evaluation of bone turnover in PD patients because they correlate well with other established bone markers and they are not influenced by renal and peritoneal clearances.

DOI： 10.1111/cen.12070

Language：English   Publishing type：Research paper (scientific journal)  

We describe a case of filariasis presenting with severe chyluria and nephrotic-range proteinuria. There were no obvious findings of glomerulonephritis in the renal biopsy. Technetium-99m-human serum albumin (Tc-99m-HSA) lymphoscintigraphy revealed the presence of communications between lymphatic channels and the urinary tract. Ezetimibe (10 mg/day) was administered during hospitalization. Chyluria was decreased within a few days following the administration of ezetimibe. Moreover, a remission was obtained from nephrotic-range proteinuria. Tc-99m-HSA lymphoscintigraphy showed a reduction of lymph flow to the urinary tract three months later. In our patient, therapeutic intervention by ezetimibe may have resulted in a reduction of chylous lymph absorption from the intestine and the prevention of mucosal rupture into the renal pelvis and calyx via reduced intralymphatic pressure. Ezetimibe may be an effective and safe treatment for this indication, and should be considered when filarial patients present with chyluria and massive proteinuria before employing invasive surgical procedures.

DOI： 10.1093/ckj/sfs110

Language：English   Publishing type：Research paper (scientific journal)  

OBJECTIVE: Phosphate binders are used in the treatment of hyperphosphatemia in peritoneal dialysis (PD) patients. An ideal phosphate binder for long-term use must be effective with little or no side effects. We evaluated the long-term efficacy and side effects of lanthanum carbonate (LaC) used in combination with other phosphate binders in PD patients. PATIENTS: The subjects of this retrospective study were 30 PD patients who received LaC at Kyushu University. The effect of LaC on various biochemical parameters (serum phosphate, calcium and parathyroid hormone), daily dose of other phosphate binders, gastrointestinal side effects, and nutritional status were determined during the 24-week treatment. We also evaluated the rate of achievement of the Japanese Society of Dialysis Treatment guidelines for secondary hyperparathyroidism and used multivariate analysis to determine the factors associated with the efficacy of LaC. RESULTS: LaC (960 ± 412 mg/day) reduced serum phosphate from 6.2 to 5.3 mg/dL. The rate of achievement of the guideline target improved after 24 weeks of LaC treatment. The dose of other phosphate binders and dialysis volume remained unchanged during the treatment. Although 53&#37; of patients experienced at least one gastrointestinal side effect, LaC treatment did not affect the nutritional status, and none of the patients discontinued LaC. Multivariate analysis identified low stature, old age and high baseline total creatinine clearance as significant factors that determine the effectiveness of LaC in PD patients. CONCLUSION: Low dose LaC treatment used in combination with other phosphate binders improved serum phosphate control with tolerable gastrointestinal symptoms in PD patients.

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Event date： 2020.6

Language：Japanese  

Country：Japan  

Event date： 2020.6

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Country：Japan  

Event date： 2020.6

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Country：Japan  

Event date： 2020.6

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Country：Japan  

Event date： 2020.6

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Country：Japan  

Event date： 2019.6

Language：Japanese  

Country：Japan  

Event date： 2020.6

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Country：Japan  

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Country：Other  

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Personalized Prediction of Net Benefit of Aspirin Use for Primary Prevention of Cardiovascular Disease in Hemodialysis Patients: the Q-Cohort Study

Language：Japanese  

IgA腎症患者における血漿浸透圧と末期腎不全発症リスクの関連

Language：Japanese  

Language：Japanese  

血液透析患者における尿素窒素・クレアチニン比と死亡、合併症罹患の関連 Qコホート研究

Language：Japanese  

経口吸着剤AST-120の腎機能に及ぼす影響 無作為化試験のメタ解析

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血液透析患者における治療抵抗性高血圧と心血管リスクの関係 Qコホート研究

Language：Japanese  

IgA腎症患者における末期腎不全発症とその危険因子の時代的推移

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血液透析患者における活性型ビタミンD受容体刺激製剤と感染症死亡の関連 Qコホート研究

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IgA腎症におけるレニン・アンジオテンシン系抑制薬の末期腎不全発症抑制効果

Language：Japanese  

IgA腎症患者におけるオックスフォード分類を使用した腎予後予測リスクスコアの作成

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3