The impact of antihypertensive therapy on cognition in patients already diagnosed with Alzheimer's disease (AD) has been unknown until now. Results of previous studies hinted at an association between high blood pressure and cognitive decline as well as possible beneficial effects of antihypertensive treatment on cognition.

Researchers, therefore, prospectively evaluated the effects of antihypertensive therapy and of the various antihypertensive subclasses on cognitive decline in 290 outpatients diagnosed with AD according to criteria in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition. The results were presented in a poster session on June 10.

Emmanuelle Duron, MD, Department of Geriatrics, Hôpital Broca, Paris, France, and colleagues assessed cognitive function in each patient using the Mini Mental State Examination (MMSE) during a follow-up of 3 years.

Mean age of participants was 78 years. Fifty-one percent of the study population used an antihypertensive therapy, with beta-blockers comprising the largest share (21%), followed by calcium channel blockers (CCB; 17%), diuretics (17%), angiotensin-converting enzyme inhibitors (15%), and angiotensin-receptor blockers (ARB; 6%).

All patients received treatment with a cholinesterase inhibitor, the first-line treatment in AD.

At study entry, Mini Mental State Examination (MMSE) scores were similar in the group receiving antihypertensive therapy and in those not receiving this therapy (22.45 vs 22.19), said Dr. Duron.

In the course of 3 years, a significant effect of the antihypertensive therapy emerged after the researchers adjusted for confounding factors such as age, gender, education level, systolic blood pressure, and MMSE at baseline.

"The decline in MMSE was significantly less pronounced in patients with antihypertensive therapy than in those without," reported Dr. Duron (P < .01).

Scores on the MMSE in the group on antihypertensive therapy and in those not taking this therapy were 22.04 and 21.27 at 1 year, 20.81 and 19.56 at 2 years, and 18.85 and 17.69 at 3 years (P < .001 for all periods).

Regarding drug classes, only CCBs seemed to have a positive effect (P < .001 compared with patients not on CCBs). Results were not significant for other antihypertensive classes, but reached near significance for ARB therapy (P = .06).

Dr. Duron added that the findings of the study are in line with literature data gained from trials which showed that antihypertensive treatment is able to prevent the occurrence of dementia.