Jan Willem van Dalen et al. conducted a study to determine whether angiotensin II–stimulating antihypertensives can lower the risk of incident dementia in comparison to angiotensin II–inhibiting antihypertensives. The study analysed 1909 individuals without dementia and found that dementia incidence was 5.6% in angiotensin II–stimulating antihypertensive users whereas it was 8.2% among users of angiotensin II–inhibiting antihypertensives; a 45% lower incident dementia rate was observed in angiotensin II–stimulating antihypertensive users.
Objective To assess whether angiotensin II–stimulating antihypertensives (thiazides, dihydropyridine calcium channel blockers, and angiotensin I receptor blockers) convey a lower risk of incident dementia compared to angiotensin II–inhibiting antihypertensives (angiotensin-converting enzyme inhibitors, β-blockers, and nondihydropyridine calcium channel blockers), in accordance with the “angiotensin hypothesis.”
Methods We performed Cox regression analyses of incident dementia (or mortality as competing risk) during 6–8 years of follow-up in a population sample of 1,909 community-dwelling individuals (54% women) without dementia, aged 70–78 (mean 74.5 ± 2.5) years.
Results After a median of 6.7 years of follow-up, dementia status was available for 1,870 (98%) and mortality for 1,904 (>99%) participants. Dementia incidence was 5.6% (27/480) in angiotensin II–stimulating, 8.2% (59/721) in angiotensin II–inhibiting, and 6.9% (46/669) in both antihypertensive type users. Adjusted for dementia risk factors including blood pressure and medical history, angiotensin II–stimulating antihypertensive users had a 45% lower incident dementia rate (hazard ratio [HR], 0.55; 95% CI, 0.34–0.89) without excess mortality (HR, 0.86; 95% CI, 0.64–1.16), and individuals using both types had a nonsignificant 20% lower dementia rate (HR, 0.80; 95% CI,0.53–1.20) without excess mortality (HR, 0.97; 95% CI, 0.76–1.24), compared to angiotensin II–inhibiting antihypertensive users. Results were consistent for subgroups based on diabetes and stroke history, but maybe specific for individuals without a history of cardiovascular disease.
Conclusions Users of angiotensin II–stimulating antihypertensives had lower dementia rates compared to angiotensin II–inhibiting antihypertensive users, supporting the angiotensin hypothesis. Confounding by indication must be examined further, although subanalyses suggest this did not influence results. If replicated, dementia prevention could become a compelling indication for older individuals receiving antihypertensive treatment.