ISI, a more valuable index of insulin sensitivity derived from OGTT, was significantly higher in both MHO-IRes (4.9 ± 1.5 vs. 2.4 ± 1.0, p < 0.01) and MHO-MetS (3.2 ± 1.5 vs. 2.5 ± 1.3; p < 0.01) patients, compared to their MUO counterparts. Here, INS is linked to metabolic syndrome.