Body Mass Index and Risk of All-Cause and Cardiovascular Disease Mortality in Patients With Type 2 Diabetes Mellitus

Abstract Context The correlations between body mass index (BMI) and risk of all-cause and cardiovascular disease (CVD) mortality in patients with type 2 diabetes mellitus (T2DM) are still controversial. Objective To explore the correlation between BMI and the risk of all-cause and CVD mortality in patients with T2DM. Methods The data sources China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, PubMed, Web of Science, Embase, and The Cochrane Library were searched up until May 25, 2024. After adjusting for confounding factors, the original study on the association between BMI and all-cause and CVD mortality in patients with T2DM was analyzed. Number of all-cause and CVD mortality events, BMI, and basic characteristics were extracted. Results Twenty-eight papers with a total of 728 321 participants were finally included. Compared to normal-weight patients with T2DM, the risk of all-cause (HR = 1.61; 95% CI [1.51, 1.72]; P = .000) and CVD (HR = 1.31; 95% CI [1.10, 1.54]; P = .002) mortality were increased in underweight patients; however, they were reduced (HR = 0.85; 95% CI [0.81, 0.89]; P = .000) and (HR = 0.86; 95% CI [0.78, 0.96]; P = .007), respectively in patients with overweight. Also, there were significant reductions in the risk of all-cause (HR = 0.85; 95% CI [0.78, 0.92]; P = .000) and CVD (HR = 0.81; 95% CI [0.74, 0.89]; P = .000] mortality in patients with mild obesity. The difference in the risk of all-cause mortality (HR = 0.98; 95% CI [0.80, 1.21]; P = .881) in patients with moderate obesity was not statistically significant. Conclusion We found that there were correlations between BMI and the risk of all-cause and CVD mortality in patients with T2DM. The obesity paradox remains.