Background
Glucose-dependent insulinotropic polypeptide, or GIP, is one of the two major incretin hormones released from the gut after eating. In healthy physiology, GIP helps stimulate insulin secretion in a glucose-dependent way, meaning it acts more strongly when blood sugar is elevated. In type 2 diabetes, however, the long-term glucose-lowering role of GIP has remained uncertain. This uncertainty is especially relevant now that incretin-based therapies are rapidly expanding, including GLP-1 receptor agonists such as semaglutide, which are already established treatments for improving glycaemic control and lowering body weight.
This study tested a simple but important question: if native GIP is infused under the skin for six weeks, does it improve glucose control in people with type 2 diabetes, either on its own or when added to semaglutide? The trial also examined whether combining the two hormones could produce an additive benefit, given that both act on related pathways involved in insulin secretion, appetite regulation, and post-meal metabolism.
