In this study, a two-sample Mendelian randomization (TSMR) with a large sample size was conducted to determine whether a genetic predisposition to increased BMI, WHR, and WHRadjBMI was causally associated with T2DM and glycemic traits, including HOMA-IR, fasting insulin, fasting glucose, and HbA1c. Here, INS is linked to type 2 diabetes mellitus.