Antihypertensive drug classes and risk of incident dementia: a multinational population-based cohort study

Background Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-II receptor blockers (ARBs) are first-line antihypertensive drugs for many patients, and influencing angiotensin systems may play a role in dementia risk. This study aimed to investigate whether exposure to different antihypertensive drug classes compared with ACEI affects the risk of dementia and pathological dementia subtypes in a large multinational database study. Methods This was a multinational population-based cohort study using electronic health databases in Hong Kong, the UK, Sweden and Australia. A common protocol was used to harmonise the study design. An active comparator, a new user design, was applied to compare the risk of all-cause dementia between different antihypertensive drug classes, with secondary outcomes of Alzheimer’s disease (AD) and vascular dementia (VaD). Adjusted Cox proportional hazards models with inverse probability of treatment weighting were used to generate results in each study site and were pooled in meta-analysis. Results One million nine hundred twenty-five thousand, five hundred sixty-three individuals were included across the four databases with a median follow-up ranging from 5.6 to 8.4 years. Compared to ACEI, initiation with ARB was associated with a reduced risk of incident all-cause dementia [hazard ratio (HR): 0.92, 95% confidence interval (CI): 0.89–0.94] and VaD (HR 0.87, 95% CI 0.78–0.96) but not AD. Conclusions This is the largest multinational cohort study conducted to date investigating different classes of antihypertensive drugs and the risk of incident dementia. When initiating antihypertensives, physicians and patients should consider the reduced risk of all-cause dementia and VaD with ARB compared with ACEI in their risk–benefit assessment.