Mortality and Cardiovascular Disease in Type 1 and Type 2 Diabetes

TLDR

Long‑term trends in excess mortality and cardiovascular risk in type 1 and type 2 diabetes have been understudied, prompting this Swedish cohort analysis. The study followed 1998‑2012 Swedish National Diabetes Register patients through 2014, matched them to age‑, sex‑, and county‑matched controls, and estimated mortality and cardiovascular trends using Cox regression and standardized incidence rates. During 1998‑2014, both type 1 and type 2 diabetes patients experienced substantial declines in mortality and cardiovascular events, with type 1 patients showing a ~40 % greater reduction in cardiovascular outcomes versus controls and type 2 patients a ~20 % greater reduction, though fatal outcomes declined less in type 2 patients compared to controls. Funding was provided by the Swedish Association of Local Authorities and Regions and other organizations.

Abstract

Long-term trends in excess risk of death and cardiovascular outcomes have not been extensively studied in persons with type 1 diabetes or type 2 diabetes.We included patients registered in the Swedish National Diabetes Register from 1998 through 2012 and followed them through 2014. Trends in deaths and cardiovascular events were estimated with Cox regression and standardized incidence rates. For each patient, controls who were matched for age, sex, and county were randomly selected from the general population.Among patients with type 1 diabetes, absolute changes during the study period in the incidence rates of sentinel outcomes per 10,000 person-years were as follows: death from any cause, -31.4 (95% confidence interval [CI], -56.1 to -6.7); death from cardiovascular disease, -26.0 (95% CI, -42.6 to -9.4); death from coronary heart disease, -21.7 (95% CI, -37.1 to -6.4); and hospitalization for cardiovascular disease, -45.7 (95% CI, -71.4 to -20.1). Absolute changes per 10,000 person-years among patients with type 2 diabetes were as follows: death from any cause, -69.6 (95% CI, -95.9 to -43.2); death from cardiovascular disease, -110.0 (95% CI, -128.9 to -91.1); death from coronary heart disease, -91.9 (95% CI, -108.9 to -75.0); and hospitalization for cardiovascular disease, -203.6 (95% CI, -230.9 to -176.3). Patients with type 1 diabetes had roughly 40% greater reduction in cardiovascular outcomes than controls, and patients with type 2 diabetes had roughly 20% greater reduction than controls. Reductions in fatal outcomes were similar in patients with type 1 diabetes and controls, whereas patients with type 2 diabetes had smaller reductions in fatal outcomes than controls.In Sweden from 1998 through 2014, mortality and the incidence of cardiovascular outcomes declined substantially among persons with diabetes, although fatal outcomes declined less among those with type 2 diabetes than among controls. (Funded by the Swedish Association of Local Authorities and Regions and others.).