Statin use and incident dementia: a nationwide cohort study of Taiwan.

BACKGROUND: Statins are widely used in clinical treatment. However, an U.S. Food and Drug Administration issued health alert has raised concerns for the adverse effects of statin-associated confusion and memory loss in the elderly people. It is necessary to clarify the relationship between statin use and risk of incident dementia as well as whether class effects exist.

METHODS: In this population-based retrospective cohort study, total 33,398 patients aged ≥ 60 years were selected from a subset of the Taiwan National Health Insurance Research Databases and followed up for tracking the occurrence of any type of dementia from 2000 to 2010. The Cox proportional hazards models were used.

RESULTS: Compared to nonusers, statin users had a significantly lower risk of incident dementia (hazard ratio [HR], 0.78; 95% CI, 0.72-0.85, p<0.001). The potency and the cumulative duration of statin utilized were associated with the reducing risk of dementia. After stratifying by gender, the risk of incident dementia was lower in female statin users (HR, 0.76; 95% CI, 0.68-0.85, p<0.001) than in male statin users (HR, 0.86; 95% CI, 0.75-0.98, p=0.024). Higher potency and longer cumulative duration of statin use were required for reducing the risk of incident dementia in male patients than in female patients.

CONCLUSION: Statin use was associated with a significantly lower risk of dementia in the elderly patients in Taiwan. The potency and the cumulative duration of statin utilized played critical roles.