Whether or not the decreased incretin effect is due to T2DM itself, or due to decreased β cell function, remains unclear.15 Of the two incretins, we focused on GLP‐1 because it potentiates insulin secretion under hyperglycaemic conditions and reduces blood glucose levels in patients with T2DM along with inhibition of gastric emptying, food intake and glucagon secretion.16 In addition to improved glycaemic control and preserving islet β cell mass, GLP‐1 has demonstrated beneficial effects on such as cardiac function and atherosclerotic plaque.17 This evidence concerns the gene GLP1R and type 2 diabetes mellitus.