GIP and diabetes mellitus: In patients with obesity and diabetes (OB+/DM+), neither GLP-1 (66.31% ± 30.11%, n = 7) nor GIP (71.74% ± 32.57%, n = 8) significantly altered BTCH-induced contraction in longitudinal muscle strips compared to control (vehicle-treated, 74.08% ± 18.93%, n = 8; P > 0.05) (Figure 6A).