Statin use and risk of Parkinson’s disease among older adults in Japan: a nested case-control study using the longevity improvement and fair evidence study

The association between statin use and the risk of Parkinson’s disease remains inconclusive, particularly in Japan’s super-aging society. This study aimed to investigate the potential association between statin use and the risk of Parkinson’s disease among Japanese participants aged ≥65 years. We used data from the Longevity Improvement and Fair Evidence Study, which included medical and long-term care claims data from April 2014 to December 2020 across 17 municipalities. Using a nested case-control design, we matched one case to five controls based on age, sex, municipality, and cohort entry year. A conditional logistic regression model was used to estimate the odds ratios with 95% confidence intervals. Among the 56,186 participants (9,397 cases and 46, 789 controls), 53.6% were women. The inverse association between statin use and Parkinson’s disease risk was significant after adjusting for multiple variables (odds ratio: 0.61; 95% confidence interval: 0.56–0.66). Compared with non-users, the dose analysis revealed varying odds ratios: 1.30 (1.12–1.52) for 1–30 total standard daily doses, 0.77 (0.64–0.92) for 31-90 total standard daily doses, 0.62 (0.52–0.75) for 91–180 total standard daily doses, and 0.30 (0.25–0.35) for >180 total standard daily doses. Statin use among older Japanese adults was associated with a decreased risk of Parkinson’s disease. Notably, lower cumulative statin doses were associated with an elevated risk of Parkinson’s disease, whereas higher cumulative doses exhibited protective effects against Parkinson’s disease development.