Body mass index and mortality in patients with type 2 diabetes mellitus: A prospective cohort study of 11,449 participants.

AIMS: To investigate the association between body-mass index and mortality in Chinese adults T2DM. METHODS: 11,449 participants of Kailuan Study with T2DM were included in this prospective cohort study. All-cause mortality was calculated using Kaplan-Meier analysis. Cox proportional hazards analysis was used to estimate the association between BMI and mortality. RESULTS: During a mean follow-up period of 7.25±1.42years, 1254 deaths occurred. The number of deaths of the underweight, normal weight, overweight, and obese group was 23, 389, 557, and 285; the corresponding mortality was 25.0%, 13.4%, 10.3%, and 9.4%, respectively. The obese group had the lowest all-cause mortality rate (log-rank chi-square=48.430, P<0.001). After adjusting for age, sex, fasting blood glucose, smoking status, systolic blood pressure, history of hypertension, stroke, cancer and myocardial infarction, compared with the normal weight group, Multivariate Cox proportional hazard regression analysis showed that HR (95% CI) of all-cause mortality in the underweight, overweight, and obese group was 1.497 (0.962, 2.330), 0.833 (0.728, 0.952), and 0.809 (0.690, 0.949). After stratifying for age tertiles, this trend remained. CONCLUSIONS: In T2DM patients in north China, the risk for all-cause mortality was lower in the overweight and the obese groups than those in the normal weight and the underweight groups.