In contrast, GIP protein expression was significantly higher in the OB+/DM− group (9.46 ± 4.27 pg/mL) than in OB+/DM+: patients (4.03 ± 2.91 pg/mL; P = 0.026) (Figure 4B), indicating a potential diabetes-associated reduction in jejunal GIP content. Here, GIP is linked to diabetes mellitus.