All-cause mortality and incidence of cardiovascular diseases in lean patients with newly diagnosed type 2 diabetes

A few studies evaluated all-cause mortality or risk of cardiovascular diseases according to the body mass index (BMI) level in patients with type 2 diabetes. We evaluated all-cause mortality and the incidence of cardiovascular diseases in lean patients with newly diagnosed type 2 diabetes in Korea. Additionally, we aimed to determine a difference in all-cause mortality and the incidence of cardiovascular diseases according to changes in BMI over time among patients with newly diagnosed type 2 diabetes in Korea. We analyzed 419,509 patients with newly diagnosed type 2 diabetes who underwent health screening between 2010 and 2014 and followed up until 2019. We conducted a multivariate Cox proportional hazards model to determine the association between BMI and all-cause mortality or risk of cardiovascular diseases. Lean patients with type 2 diabetes had a higher risk of all-cause mortality (hazard ratio [HR]: 2.106, 95% confidence interval [CI]: 1.974-2.248), cardiovascular disease (HR: 1.132, 95% CI: 1.078, 1.189), coronary heart disease (HR: 1.219, 95% CI: 1.124-1.323), heart failure (HR: 1.405, 95% CI: 1.279-1.543), stroke (HR: 1.155, 95% CI: 1.024-1.302), and ischemic stroke (HR: 1.205, 95% CI: 1.045-1.388) compared to patients with type 2 diabetes and normal BMI. Patients with newly diagnosed type 2 diabetes had the highest all-cause mortality when they remained lean during the follow-up. Our findings underscore the critical role of maintaining an appropriate weight status to reduce all-cause mortality and incidence of cardiovascular diseases among lean patients with newly diagnosed type 2 diabetes.