Impact of statin treatment on cardiovascular risk in patients with type 1 diabetes: a population-based cohort study

BACKGROUND: Cardiovascular disease (CVD) is a major complication in type 1 diabetes mellitus (T1D) patients. Previous studies have suggested that statins may be helpful for prevention of CVD in T1D, but there are limited data on the role of statins in T1D. We investigated the relationship between statin treatment and cardiovascular risk in T1D patients using a population-based cohort. METHODS: We conducted a retrospective cohort study using the Korean nationwide health insurance database from January 2007 to December 2017. This study included 11,009 T1D patients aged ≥ 20 years without a prior history of CVD. The primary outcome was a composite development of stroke or myocardial infarction. Statin use during follow-up was treated as a time-varying variable. We performed a multivariable time-dependent Cox regression analysis adjusting for sex, age, type of insurance, hypertension, renal disease, and use of antiplatelets and renin–angiotensin–aldosterone system inhibitors. RESULTS: During the mean follow-up of 9.9 ± 3.7 years of follow-up, 931 T1D patients (8.5%) suffered primary outcome. Statin treatment was associated with a reduced risk of the primary outcome (adjusted hazard ratio, 0.76; 95% confidence interval 0.66–0.88; p < 0.001). Statin use led to decreased risks of ischemic stroke and myocardial infarction, but was not related to hemorrhagic stroke. We also found that the risk of cardiovascular events decreased as the cumulative exposure duration of statins increased. CONCLUSIONS: Statin use was associated with a lower risk of cardiovascular events in T1D patients. Further prospective studies are needed to confirm the potential role of statins in prevention of CVD in patients with T1D.