The relative GLP-1 protein expression in jejunal muscular tissue showed significant tendency to increase in obese patients with diabetes (OB+/DM+: 3.62 ± 0.98 pg/mL) compared to obese patients without diabetes (OB+/DM−: 2.77 ± 0.54 pg/mL), as shown in Figure 4A (P = 0.037). Here, GCG is linked to diabetes mellitus.