Occurrence and progression of dementia in a community population aged 75 years and older: relationship of antihypertensive medication use.

OBJECTIVE To examine whether antihypertensive medication use can affect the occurrence and progression of dementia. SUBJECTS AND METHODS In a community cohort of 1810 persons aged 75 years and older, 225 prevalent cases of dementia were detected. Among the 1301 persons without dementia, 224 incident cases of dementia were identified during an average period of 3 years. Among the 225 prevalent cases of dementia, 79 were suitable for the analysis of cognitive decline. Information on drug use was collected for the 2 weeks preceding the baseline interview. RESULTS Subjects taking antihypertensive medication (n = 651, 83.9% of whom took diuretics) had a lower prevalence of dementia than those not taking antihypertensive medication (P<.001). Subjects without dementia who were taking antihypertensive medication at baseline (n = 584) had a reduced incidence of dementia (adjusted relative risk, 0.7; 95% confidence interval, 0.6-1.0; P = .03). Furthermore, subjects taking diuretics (n = 484) had an adjusted relative risk of 0.7 (95% confidence interval, 0.5-1.0; P = .02) for all dementia, and subjects taking diuretic monotherapy (n = 345) had an adjusted relative risk of 0.6 (95% confidence interval, 0.4-0.9; P = .006). The use of other antihypertensive medication (calcium antagonists or beta-blockers), however, was related to a reduced risk of Alzheimer disease (adjusted relative risk, 0.6; 95% confidence interval, 0.3-1.2) only in the subpopulation with a higher baseline blood pressure (n = 458). Patients with dementia at baseline who were not taking diuretics had a 2-fold faster rate of decline in the score on the Mini-Mental State Examination than those taking diuretics. CONCLUSION The use of diuretics may protect against dementia in elderly persons.