GIP and type 2 diabetes mellitus: Both GLP-1 and GIP belong to the incretin system that regulates hormone secretion in response to carbohydrate intake.32 Although the effect of GIP has been found to be greatly attenuated in patients with type 2 diabetes,33 subsequent research has shown that islet β-cell sensitivity to GIP may be restored with glycemic control.34 Glucose-dependent insulinotropic polypeptide acts in the central nervous system by blocking nausea and emesis from GLP-1 agonism without affecting satiety or energy intake reduction,35 thereby improving overall treatment tolerability.