Effects of telmisartan on cognition and regional cerebral blood flow in hypertensive patients with Alzheimer's disease

AIM: Recent studies have shown that some antihypertensive medications are associated with a significant reduction in the incidence of Alzheimer's disease (AD). However, it remains uncertain whether antihypertensive drugs may have a preventive effect on cognitive decline in patients with AD. We investigated the effects of telmisartan, an angiotensin II type 1 receptor blocker with peroxisome proliferator-activated receptor γ-stimulating activity, on cognition and regional cerebral blood flow (rCBF) in elderly hypertensive patients with AD. METHODS: A total of 20 patients with probable AD and essential hypertension were randomly assigned to the telmisartan group (n = 10, 40-80 mg daily) or the amlodipine group (n = 10, 5-10 mg daily) for 6 months. RESULTS: The groups had a similar significant reduction in systolic and diastolic blood pressure after treatment. The telmisartan group did not show any changes in cognitive function test scores, while the amlodipine group showed significantly higher scores on the AD Assessment Scale-Cognitive Subscale (Japanese version). Analysis of covariance to analyze treatment effect revealed that the telmisartan group showed increased rCBF in the right supramarginal gyrus, superior parietal lobule, cuneus, and lingual gyrus compared with the amlodipine group, while the amlodipine group showed increased rCBF only in the right cingulate gyrus compared with the telmisartan group at 6 months. CONCLUSION: These findings suggest that telmisartan may have additional benefits and be useful for the treatment of elderly hypertensive patients with AD.