Association between statin use and cataract formation in a retrospective cohort study using Japanese health screening and claims data

In this retrospective cohort study of data (recorded between 1 January 2005 and 31 December 2017) from a commercially available health screening and insurance claims database of the working-age Japanese population, we examined the association of statin use with cataract formation. Using the health screening data, we identified 1,178,560 patients who met the dyslipidaemia criteria; among them, 724,200 patients were enrolled. Based on person-years, the cohort was categorised by statin non-use and new use. Unadjusted, age–sex-adjusted, and multivariate-adjusted hazard ratios (hazard ratios [HRs]; with their 95% confidence intervals [CIs]) were estimated, and intergroup comparisons were undertaken using Cox proportional hazards regression. An increased risk of cataract incidence was associated with statin use (adjusted HR [95% CI]) compared with statin non-use (1.56 [1.43–1.70]). The adjusted HRs [95% CI] for cataract incidence for low- and high-potency statins were 1.48 [1.30–1.70] and 1.61 [1.44–1.79], respectively, whereas those for lipophilic and hydrophilic statins were 1.56 [1.39–1.75] and 1.56 [1.38–1.75], respectively. The adjusted HR for statin use with incidence of cataract was 1.35–1.73, except for fluvastatin and simvastatin. In the middle-aged Japanese working population, statin use was associated with a 1.5- to 1.6-fold higher risk of cataracts.