Abstract
Dementia affects 55 million people globally, with the number projected to triple by 2050. Statins, widely prescribed for cardiovascular benefits, may also have neuroprotective effects, although studies on their impact on dementia risk have shown contradictory results. In this systematic review and meta-analysis, we searched PubMed, Embase, and Cochrane following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We assessed the risk of dementia, Alzheimer's disease (AD), and vascular dementia (VaD), with subgroup analyses by gender, statin type, and diabetes status. Fifty-five observational studies including over 7 million patients were analyzed. Statin use significantly reduced the risk of dementia compared to nonusers (hazard ratio [HR] 0.86; 95% confidence interval [CI]: 0.82 to 0.91; p < 0.001). It was also associated with reduced risks of AD (HR 0.82; 95% CI: 0.74 to 0.90; p < 0.001) and VaD (HR 0.89; 95% CI: 0.77 to 1.02; p = 0.093). Subgroup analyses revealed significant dementia risk reductions among patients with type 2 diabetes mellitus (HR 0.87; 95% CI: 0.85 to 0.89; p < 0.001), those with exposure to statins for more than 3 years (HR 0.37; 95% CI: 0.30 to 0.46; p < 0.001), and populations from Asia, where the greatest protective effect was observed (HR 0.84; 95% CI: 0.80 to 0.88). Additionally, rosuvastatin demonstrated the most pronounced protective effect for all-cause dementia among specific statins (HR 0.72; 95% CI: 0.60 to 0.88). Our findings underscore the neuroprotective potential of statins in dementia prevention. Despite the inherent limitations of observational studies, the large dataset and detailed subgroup analyses enhance the reliability of our results. Future randomized clinical trials are necessary to confirm these findings and enlighten clinical guidelines. HIGHLIGHTS: Largest meta-analysis to date on statins and dementia risk, including 55 studies and more than 7 million patients.Statin use linked to lower risks of all-dementia, AD, and VaD.Numerous significant subgroup results highlight statins' diverse neuroprotective effects.Findings support statins as a public health tool, especially in low-income countries.Future research should explore the impact of statins across diverse patient populations.