Effects of antihypertensive therapy on cognitive decline in Alzheimer's disease

Therapeutic trials concerning the effect of antihypertensive therapy on cognition have produced controversial findings. Our objective was to evaluate the impact of antihypertensive therapy on the cognitive function in subjects already diagnosed with Alzheimer's disease (AD).

We conducted an observational study in a memory clinic assessing outpatients suffering from AD. A total of 321 patients were included. Cognitive function was assessed yearly by the Mini-Mental State Examination (MMSE; score/30).

The mean age of patients was 78.1 +/- 6 years, 54% of them received antihypertensive therapy and the mean MMSE scores were similar in both groups (patients taking antihypertensive therapy and patient without antihypertensive therapy). The mean follow-up was 34.1 +/- 6 months. MMSE means were significantly higher among patients using antihypertensive therapy compared to those without antihypertensive therapy (MMSE scores = 21.9 +/- 4.9 vs. 21.2 +/- 5.1 at 1 year (P = 0.001); 20.8 +/- 5.5 vs. 19.4 +/- 5.7 at 2 years (P < 0.001); 19.0 +/- 6.7 vs. 17.5 +/- 6.4 at 3 years (P < 0.001)), after adjustment for age, gender, education level, systolic blood pressure (SBP), and diastolic blood pressure (DBP) at baseline, MMSE at baseline, coronary heart disease, statins, and antiplatelet agents' consumption. Furthermore, the use of antihypertensive therapy was associated with a lower estimated risk of cognitive decline (as defined by a decrease of at least one point in MMSE score over time) (hazard ratio = 0.61; 95% confidence interval = 0.45-0.81) after adjustment for the same factors.

These results suggest an association between antihypertensive therapy, a lower decrease in mean MMSE and a lower cognitive decline over time in AD.