Statin May Reduce Risk of Dementia and Parkinson's Disease

BOSTON, July 19 -- Simvastatin (Zocor) may enrich the brain as well as help sustain the heart, according to researchers here.
The statin reduced the risk of incident dementia by more than 54% and the risk of newly acquired Parkinson's disease by 49% in patients 65 or older, Benjamin Wolozin, M.D., of Boston University, and colleagues, reported online in BMC Medicine
Analysis of data from the 4.5 million men and women included in the Veterans Affairs database found a significant protective effect for simvastatin (P <0.0001 for both), but not for lovastatin (Mevacor), Benjamin Wolozin, M.D., of Boston University School of Medicine, and colleagues reported online in BMC Medicine.
There was also a non-significant reduction in risk of incident dementia among patients taking atorvastatin (Lipitor) (HR 0.91, 95% CI 0.80-1.02, P =0.11), they wrote.
They compared those taking lovastatin, atorvastatin, or simvastatin with those using warfarin (Coumadin) or an unidentified mixture of other cardiovascular drugs. The data were analyzed using three Cox proportional hazard models, one that adjusted for age, a second that adjusted for hypertension, cardiovascular disease or diabetes, all known risk factors for dementia, and a third that included the Charlson index, which is used to assess severity of chronic disease.
The study included data from 1,290,071 participants who took some type of cardiovascular medicine including 727,128 who used simvastatin, 53,869 who took atrovastatin, 53,369 who took warfarin, and 54,052 lovastatin users. It also included data from 394,739 patients who used a variety of cardiovascular drugs.
Among the findings:
After adjusting for age, presence of known dementia risk factors, and Charlson index, simvastatin was associated with a 54% reduction in risk of incident dementia (HR 0.46, 95% CI 0.44-0.48, P <0.0001).
After adjusting for age, presence of known dementia risk factors, and Charlson index, lovastatin was associated with a non-significant 5% reduction in risk of incident dementia (HR 0.95, 95% CI 0.86-1.05, P =0.34).
After adjusting for age, presence of diabetes, hypertension, or other cardiovascular disease, the HR for new onset Parkinson's disease was 0.51 for patients taking simvastatin (95% CI 0.49-0.55 P <0.0001).
The authors said although the large sample size, the ability to track subjects using a comprehensive database, and the ability to analyze the data by specific statin type were all strengths of the study, the results were nonetheless limited by its retrospective design. Some of these limitations were offset by the use of two comparators-warfarin and the catchall cardiovascular drugs category.
But as the authors concluded, more studies are needed to determine whether the apparent protective effect "represents a biological action of simvastatin or an unanticipated statistical bias in the database."
Dr. Wolozin disclosed that he had a patent for the use of statin therapy for Alzheimer's disease. The authors said the study was supported by "an anonymous foundation." Additional source: BMC MedicineSource reference: Wolozin B et al "Simvastatin is associated with a reduced incidence of dementia" BMC Medicine 2007 (in press)