Dapagliflozin increased pancreatic beta cell proliferation and insulinogenic index in mice fed a high-fat and high-sodium chloride diet

Abstract

People in Eastern Asia, including Japan, traditionally consume higher amounts of sodium chloride than in the United States and Western Europe, and it is common knowledge that impaired insulin secretion—rather than insulin resistance—is highly prevalent in Asian people who have diabetes mellitus. We previously reported that mice fed a high-fat and high-sodium chloride (HFHS) diet had a relatively lower degree of obesity than mice fed a high-fat diet, but had a comparatively impaired insulin secretion. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have been shown to dampen down the sympathetic nervous system, which reportedly is activated by a high-sodium chloride diet. In this study, we examined the effects of dapagliflozin, a SGLT2 inhibitor, on glucose metabolism and insulin secretion in mice fed a HFHS diet. C57BL6/J mice were fed a HFHS diet for 6 weeks and subsequently divided into two treatment groups fed: (1) a HFHS diet mixed with dapagliflozin for up to 3 weeks (HFHS + Da) and (2) a HFHS diet without dapagliflozin (HFHS). Dapagliflozin improved glucose tolerance and the insulinogenic index accompanied by increased pancreatic beta cell proliferation. Furthermore, dapagliflozin decreased both the tyrosine hydroxylase-positive area in pancreatic islets and catecholamine excretion in urine. Our results suggest that dapagliflozin improved insulin secretion by suppressing sympathetic nerve activation in mice fed a HFHS diet.