Potentiation of glucose-induced insulin secretion by GIP is diminished in chronic hyperglycaemic states due at least in part to a decrease in the Gs subtype of the GIP receptor in pancreatic beta cells, and further reasons for concern over GIP as a treatment for type 2 diabetes are that it increases glucagon secretion and adipose deposition [49]. This evidence concerns the gene GIP and type 2 diabetes mellitus.