Statin Use and the Risk of Dementia in Patients with Stroke: A Nationwide Population-Based Cohort Study

Background: Patients with stroke have an increased risk of dementia. Some studies have found that statin use might lower the risk of incident dementia; however, there is still a lack of data from patients with stroke. Therefore, the aim of our study was to investigate the impact of statin use on the risk of dementia in patients with stroke. Methods: We used the National Health Insurance Research Database in Taiwan to identify 14,807 patients diagnosed with stroke from 1997 to 2005. These patients were classified as statin users and nonusers. Propensity score matching was performed to balance selected confounders between the statin users and nonusers. Cox proportional hazard regression models were used to evaluate the association between statin use and the risk of dementia. Results: During the follow-up period (median, 7.5 years), 1895 patients were diagnosed with incident dementia. Statin use was associated with a significantly lower incidence of dementia (adjusted hazard ratio, .81; 95% confidence interval, .73-.89) than nonuse was. In particular, lipophilic and high-potency statins were associated with lower risk of dementia. Statin exposure duration was inversely related to the risk of dementia (P < .001 for the trend). No significant effect modification for the relationship between statin use and the risk of dementia was found for either age or sex. Conclusion: In this nationwide cohort study, statin use was associated with decreased risk of dementia among patients with stroke. The use of high-potency statins, lipophilic statins, and prolonged exposure to statins may be associated with greater benefits.