INS and type 2 diabetes mellitus: T2DM was more severe in RYGB patients, with longer diabetes duration (6.1 ± 7.1 vs. 3.1 ± 4.7 years; median 4.0 years [IQR 1.0–9.0] vs. 1.0 years [IQR 0.1–3.0], p < 0.001) and higher insulin use (33.6% vs. 7.2%, p < 0.001).