In the present study, we applied a two-sample bidirectional MR framework to figure out the bidirectional causal associations of pulmonary function parameter, estimated by FEV1, FVC, and FEV1/FVC ratio, with four glycemic traits (fasting glucose, fasting insulin, glycated hemoglobin A1c [HbA1c], and fasting proinsulin levels) as well as risk of T2D. Here, INS is linked to type 2 diabetes mellitus.