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

The correlation 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. To explore the correlation between BMI and the risk of all-cause and CVD mortality in patients with T2DM. Data sources of CNKI, Wanfang, PubMed, Web of Science, Embase, and the Cochrane Library were searched until 25th May 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. 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=0.000] and CVD [HR=1.31, 95% CI: (1.10, 1.54), P=0.002] mortality were increased in underweight patients; however, they were reduced [HR=0.85, 95% CI: (0.81,0.89), P=0.000] and [HR=0.86, 95% CI: (0.78,0.96), P=0.007] 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=0.000] and CVD [HR=0.81, 95% CI: (0.74, 0.89), P=0.000] 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=0.881] in patients with moderate obesity was not statistically significant. 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.