||Honda H, Hamasaki H, Okamoto T, Ninomiya T, Iwaki T, Trends in dementia prevalence over 31 years of the Hisayama study, International Congress of Neuropathology, 2018.07, Introduction: In Japan, dementia has become a serious social problem. The Hisayama study is a prospective cohort study of lifestyle-related diseases including dementia that was started in1961. In the population-based study, it has been reported that all-cause dementia and Alzheimer’s disease (AD) significantly increased in recent years.
Methods: The aim of this study is to clarify the trends in dementia using data from 1371 autopsied performed over the past 31 years (1986-2016). Throughout the whole period, the autopsy rate is about 75%. We divided the 1371 autopsy samples into five groups according to the year of death: I (1986–1991, 257 cases), II (1992–1997, 268 cases), III (1998–2004, 318 cases), IV (2005–2011, 296 cases), and V (2012–2016, 232 cases). In addition, we investigated the increases in brain pathology related to AD using automated morphometric analyses for quantifying tau pathology.
Results: The prevalence of all-cause and AD significantly increased. A significant increasing trend was observed in both men and women. A rapid increase in senile dementia of the NFT type (SD-NFT) in recent years was notable. The morphometric analyses revealed a significant increasing of tau pathology in recent years. The significance was also observed regardless of the senile plaques.
Conclusion: We revealed a recent trend of increased tauopathy such as AD and SD-NFT, which is partly independent of amyloid-β pathology. Although aging is considered one of the important risk factors accelerating tau pathology, there could be other risk factors associated with lifestyle diseases..