Statin use and risk of dementia or Alzheimer's disease: a systematic review and meta-analysis of observational studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational (cohort and case-control) studies
PubMed 34871380 · doi:10.1093/eurjpc/zwab208
What was done
A systematic review and random-effects meta-analysis of observational (cohort and case-control) studies searched across PubMed, Cochrane, and EMBASE up to January 2021. The study compared statin users to non-users for the primary outcomes of all-cause dementia and Alzheimer's disease (AD) risk. Pooled effect sizes were calculated using restricted maximum-likelihood random-effects models and reported as odds ratios (ORs) with 95% confidence intervals (CIs).
What was found
Statin use was significantly associated with a decreased risk of all-cause dementia (36 studies; OR 0.80, 95% CI 0.75–0.86) and Alzheimer's disease (21 studies; OR 0.68, 95% CI 0.56–0.81). In sex-stratified analysis, risk reduction for dementia was identical for men (OR 0.86, 95% CI 0.81–0.92) and women (OR 0.86, 95% CI 0.81–0.92). Lipophilic and hydrophilic statins showed similar risk associations. High-potency statins were associated with a 20% dementia risk reduction versus 16% for low-potency statins, with borderline significance for subgroup heterogeneity (p = 0.05).
Why it matters
These results counter concerns that statin therapy promotes cognitive impairment and instead suggest a potential neuroprotective association across sexes and drug classes.
Limits
The underlying evidence relies entirely on observational studies, which are susceptible to confounding by indication, healthy-user bias, and survivor bias. The abstract does not report individual participant numbers, duration of exposure, specific dosages, or detailed control for cardiovascular comorbidities.
Cited by
- supports Clinical trial evidence shows no difference between lipophilic (hydrophobic) and hydrophilic statins with respect to dementia and Alzheimer's disease outcomes.