Association Between Use of Lipid-Lowering Therapy and Cardiovascular Diseases and Death in Individuals With Type 1 Diabetes

Abstract

Objective: To evaluate the effect of lipid-lowering therapy (LLT) in primary prevention on cardiovascular disease (CVD) and death in type 1 diabetes.

Research design and methods: We used the Swedish National Diabetes Register (NDR) to perform a propensity score-based study. Propensity scores for treatment with LLT were calculated from 32 baseline clinical and socioeconomic variables. The propensity score was used to estimate the effect of LLT in the overall cohort (by stratification). We estimated risk of acute myocardial infarction, stroke, coronary heart disease, and cardiovascular and all-cause mortality in individuals with and without LLT using Cox regression. A total of 24,230 individuals included in 2006-2008 NDR with type 1 diabetes without a history of CVD were followed until 31 December 2012; 18,843 were untreated and 5,387 treated with LLT (97% statins). The mean follow-up was 6.0 years.

Results: The propensity score allowed balancing of all 32 covariates, with no differences between treated and untreated after accounting for propensity score. Hazard ratios (HRs) for treated versus untreated were as follows: cardiovascular death 0.60 (95% CI 0.50-0.72), all-cause death 0.56 (0.48-0.64), fatal/nonfatal stroke 0.56 (0.46-0.70), fatal/nonfatal acute myocardial infarction 0.78 (0.66-0.92), fatal/nonfatal coronary heart disease 0.85 (0.74-0.97), and fatal/nonfatal CVD 0.77 (0.69-0.87).

Conclusions: This observational study shows that LLT is associated with 22-44% reduction in the risk of CVD and cardiovascular death among individuals with type 1 diabetes without history of CVD and underlines the importance of primary prevention with LLT to reduce cardiovascular risk in type 1 diabetes.