Metabolic and endocrine effects of SGLT2 inhibition

Abstract: Obesity and type 2 diabetes (T2D) are two growing global health problems with similar comorbidity profiles. SGLT2 inhibitors (SGLT2i) improve blood glucose control and can relieve both T2D and obesity, as well as their associated health problems such as hypertension, kidney failure, and cardiovascular disease.In paper I, 50 obese patients without diabetes were treated for 24 weeks with SGLT2i dapagliflozin + GLP-1 receptor agonist (GLP-1RA) exenatide or placebo. They were examined regarding body weight loss and body composition. The placebo-adjusted weight loss was 4.13 kg, mostly attributable to adipose tissue loss.In paper II, 43 completers of the study in paper I entered a 28-week extension phase in which all participants received active treatment. We found major reductions in body weight, adipose tissue volume, blood pressure and prediabetes that were sustained at 52 weeks. In paper III, 84 patients with T2D and non-alcoholic fatty liver disease underwent a 12-week treatment with dapagliflozin, omega-3 (n-3) carboxylic acids (OM-3CA), the combination of both or placebo to assess effects on liver fat content. MRI showed significant reductions of liver fat versus baseline and, for the combination, versus placebo.In paper IV: 15 metformin-treated patients with T2D were assessed for changes in plasma glucagon levels following a single dose of dapagliflozin during experiments with stable versus falling plasma glucose. Changes in glucagon levels could largely be explained by changes in glucose levels.In conclusion, SGLT2 inhibition can lower body weight and cardiovascular risk factors in obese patients without diabetes when combined with GLP-1RA, and it can reduce liver fat in T2D patients, in particular when given together with OM-3CA. SGLT2i effects on glucagon secretion can largely be explained by lower glucose levels rather than direct α-cell effects.