FGF19 and diabetes mellitus: One year after SG, the DM-CR group had significantly lower FGF 19 levels (126.3 ± 50.5 vs. 200.6 ± 46.9 pg/mL, p < 0.05), higher insulin levels (5.4 ± 2.7 vs. 2.4 ± 0.7 μU/mL, p < 0.05), lower glycated hemoglobin levels (5.5 ± 0.2 vs. 6.3 ± 0.4 %, p < 0.001), and higher HOMA-β index (110.8 ± 127.9 vs. 20.4 ± 15.0, p = 0.01) 1 year after SG than the DM-non-CR group.