Midlife and Late-Life Blood Pressure and Dementia in Japanese Elderly

Abstract

The associations between blood pressure and dementia have been inconclusive. We followed up a total of 668 community-dwelling Japanese individuals without dementia, aged 65 to 79 years, for 17 years and examined the associations of late-life and midlife hypertension with the risk of vascular dementia and Alzheimer disease using the Cox proportional hazards model. During the follow-up, 76 subjects experienced vascular dementia and 123 developed Alzheimer disease. The age- and sex-adjusted incidence of vascular dementia significantly increased with elevated late-life blood pressure levels (normal: 2.3, prehypertension: 8.4, stage 1 hypertension: 12.6, and stage 2 hypertension: 18.9 per 1000 person-years; Ptrend<0.001), whereas no such association was observed for Alzheimer disease (Ptrend=0.88). After adjusting for potential confounding factors, subjects with prehypertension and stage 1 or stage 2 hypertension had 3.0-fold, 4.5-fold, and 5.6-fold greater risk of vascular dementia, respectively, compared wit...