As a result, the significance of the incretin effect for the maintenance of glucose homeostasis is clearly established in human T2DM patients,24 and also in experimental animals with T2DM including Zucker fatty diabetic rats25 and WBKDF rats.17 Similarly, in the present study, we found a significant reduction in plasma glucose levels and glucose tolerance aggravated by HFD supplementation in WBKDF rats. Here, GCG is linked to type 2 diabetes mellitus.