Renin-angiotensin system inhibitor is better in slowing progression of mild cognitive impairment (mci): a meta-analysis on antihypertensive drug and risk of dementia in mci patient

Objective: Antihypertensive drugs has been known to reduce risk of mild cognitive impairment (MCI) and dementia in hypertensive patients. The current meta-analysis aims to assess association of antihypertensive drugs and risk of dementia in MCI patients. Design and method: PubMed, Embase and Web of Science were searched for articles from database inception until October, 2022. Longitudinal cohort studies in subjects aged 18 or above with MCI at baseline involving (1) comparison of use of antihypertensive drugs and non-user, or (2) comparison among classes of antihypertensive drugs were included. Primary outcome was risk of dementia. Reported risk of dementia was extracted as hazard ratio or odds ratio. Peto fixed effects meta-analysis was performed to estimate the pooled effect size of antihypertensive drugs on risk of dementia. Results: Eight studies were included in current analysis. One was post-hoc analysis of randomised controlled trial, while the others were observational cohort study. A total number of 1,107 dementia cases were identified. Use of antihypertensive drugs, regardless of therapeutic class, reduced risk of dementia by 27% (Peto odds ratio (OR) 0.73, 95% confidence interval (CI) 0.62-0.86). Use of renin-angiotensin system (RAS) inhibitor, including angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB), reduced risk of dementia by 47% (Peto OR 0.53, 95% CI 0.39-0.72), while use of non-RAS antihypertensives reduced risk of dementia by 28% (Peto OR 0.72, 95% CI 0.57-0.91). When directly comparing use of RAS and non-RAS antihypertensives, RAS inhibitor further reduced 20% risk of dementia (Peto OR 0.80, 95% CI 0.68-0.94). Among RAS inhibitor, ARBs showed trend of reducing dementia risk but could not achieve statistical significance (Peto OR 0.85, 95% CI 0.69-1.06). Conclusions: Antihypertensive drug reduced risk of dementia in MCI patients. Among different classes of antihypertensive drugs, RAS inhibitor performed better than other non-RAS antihypertensive drug in slowing progression of mild cognitive impairment to dementia, while ARB and ACEI were comparable in this aspect.