Statins, plasma cholesterol, and risk of Parkinson's disease: A prospective study

Previous findings on the association of statins, plasma lipids, and Parkinson's disease (PD) are confounded by the fact that statins also affect lipid profiles. We prospectively examined plasma lipids and statin use in relation to PD in the Atherosclerosis Risk in Communities (ARIC) Study. Statin use and plasma lipids were assessed at baseline (visit 1, 1987-89) and at three triennial visits thereafter (visits 2-4) until 1998. Potential PD cases were identified from multiple sources and validated where possible. The primary analysis was limited to incident PD cases diagnosed between 1998 and 2008. Odds ratios and 95% confidence intervals were derived from multivariate logistic regression models. Statin use was rare at baseline (0.57%) but increased to 11.2% at visit 4. During this time frame, total-cholesterol levels decreased, particularly among statin users. Fifty-six PD cases were identified after 1998. Statin use before 1998 was associated with significantly higher PD risk after 1998 (odds ratio=2.39, 95% confidence interval 1.11-5.13) after adjusting for total cholesterol and other confounders. Conversely, higher total cholesterol was associated with lower risk for PD after adjustment for statin usage and confounders. Compared with the lowest tertile of average total cholesterol, the odds ratios for PD were 0.56 (0.30-1.04) for the second and 0.43 (0.22-0.87) for the third tertile (P_trend=0.02). Statin use may be associated with a higher PD risk, whereas higher total cholesterol may be associated with lower risk. These data are inconsistent with the hypothesis that statins are protective against PD.