Purpose: To examine the relation of systolic and diastolic blood pressure to incident Alzheimer's disease (AD) and rate of cognitive change.
Methods: Longitudinal cohort study with annual clinical evaluations. At baseline, blood pressure was measured, apolipoprotein E (APOE) genotyping was performed, and medications were reviewed.
Results: 824 older Catholic clergy members without baseline dementia were recruited from across the United States. During a mean of about 6 years of observation, 151 persons developed AD. In a proportional hazards model adjusted for age, sex and education, neither systolic (relative risk = 0.995; 95% CI: 0.986, 1.004, p = 0.249) nor diastolic (relative risk = 1.000; 95% CI: 0.985, 1.015, p = 0.975) blood pressure was related to AD incidence. In mixed effects models, neither systolic nor diastolic blood pressure was related to level or to annual rate of change on a global measure of cognition. These results did not change in subsequent models that accounted for the use of medications with antihypertensive properties or for the possession of an APOE epsilon4 allele.
Conclusions: In a cohort of older persons with a majority taking medications with antihypertensive properties, we did not find a relationship between blood pressure and risk of AD or cognitive decline.