Dementia occurring over a 32-year follow-up attributable to hypertension observed at different ages: Implications for dementia prevention

Introduction: The fraction of dementia attributable to hypertension might vary depending on the age of the population considered and the age through which dementia occurs. Methods: In the Atherosclerosis Risk in Communities study, we quantified population attributable fractions (PAF) of dementia by age 80 and 90 from hypertension assessed at ages of 45–54 (n = 7572), 55–64 (n = 12,033), 65–74 (n = 6561), and 75–84 (n = 2086). Results: The PAF for dementia by age 80 from all non-normal blood pressure at ages 45–54 was 15.3% (95% confidence interval [CI] = 6.9%–22.3%), 19.1% (95% CI = 9.9%–26.9%) at ages 55–64, and 19.9% (95% CI = −4.4%–38.5%) at ages 65–74. The strongest PAFs were from stage 2 hypertension (11.9%–21.3%). For dementia by age 90, PAFs from non-normal blood pressure up through age 75 were smaller (10.9%–13.8%), and non-significant by age 75–84. Discussion: Interventions targeting hypertension even in early late life might reduce a sizeable proportion of dementia. Highlights: We estimated prospective population attributable risks of dementia for hypertension. 15%–20% of dementia cases by age 80 are from non-normal blood pressure (BP). Associations between hypertension and dementia persisted through age 75. Midlife to early late-life BP control might reduce a large proportion of dementia.