Compliance in Primary Prevention With Statins and Associations With Cardiovascular Risk and Death in a Low-Risk Population With Type 2 Diabetes Mellitus

Background We examined whether primary prevention with statins and high adherence to statins reduce the associated risk of cardiovascular events or death in a low-risk population with type 2 diabetes mellitus (T2D). Methods and Results Using Danish nationwide registers, we included patients with new-onset T2D, aged 40 to 89 years, between 2005 and 2011, who were alive 18 months following the T2D diagnosis (index date). In patients who purchased statins within 6 months following T2D diagnosis, we calculated the proportion of days covered (PDC) within 1 year after the initial 6-month period. We studied the combined end point of myocardial infarction, stroke, or all-cause mortality, whichever came first, with Cox regression. Reported were standardized 5-year risk differences for fixed comorbidity distribution according to statin treatment history, stratified by sex and age. Among 77 170 patients, 42 975 (56%) were treated with statins, of whom 31 061 (72%) had a PDC ≥80%. In men aged 70 to 79 years who were treated with statins, the standardized 5-year risk was 22.9% (95% CI, 21.5%-24.3%), whereas the risk was 29.1% (95% CI, 27.4%-30.7%) in men not treated, resulting in a significant risk reduction of 6.2% (95% CI, 4.0%-8.4%), P<0.0001. The risk reduction associated with statins increased with advancing age group (women: age 40-49 years, 0.0% [95% CI, -1.0% to 1.0%]; age 80-89 years, 10.8% [95% CI, 7.2%-14.4%]). Standardizing to all patients treated with statins, PDC <80% was associated with increased risk difference (reference PDC ≥80%; PDC <20%, 4.2% [95% CI, 2.9%-5.6%]). Conclusions This study supports the use of statins as primary prevention against cardiovascular diseases or death in 18-month surviving low-risk patients with T2D, with the highest effect in the elderly and adherent patients.