Dehydration and insulinopenia are necessary and sufficient for euglycemic ketoacidosis in SGLT2 inhibitor-treated rats

Abstract

Sodium-glucose transport protein 2 (SGLT2) inhibitors are a class of anti-diabetic agents; however, concerns have been raised about their potential to induce euglycemic ketoacidosis and to increase both glucose production and glucagon secretion. The mechanisms behind these alterations are unknown. Here we show that the SGLT2 inhibitor (SGLT2i) dapagliflozin promotes ketoacidosis in both healthy and type 2 diabetic rats in the setting of insulinopenia through increased plasma catecholamine and corticosterone concentrations secondary to volume depletion. These derangements increase white adipose tissue (WAT) lipolysis and hepatic acetyl-CoA content, rates of hepatic glucose production, and hepatic ketogenesis. Treatment with a loop diuretic, furosemide, under insulinopenic conditions replicates the effect of dapagliflozin and causes ketoacidosis. Furthermore, the effects of SGLT2 inhibition to promote ketoacidosis are independent from hyperglucagonemia. Taken together these data in rats identify the combination of insulinopenia and dehydration as a potential target to prevent euglycemic ketoacidosis associated with SGLT2i.

Fig. 1

Dapagliflozin causes increases in rates of hepatic ketogenesis and glucose production due to extracellular volume depletion. a–d Plasma glucose, bicarbonate, acetoacetate, and β-OHB concentrations. In panel c, n = 7 dapagliflozin-treated and n = 6 in all other groups. e, f Whole-body β-OHB and fatty acid turnover. g Plasma insulin concentrations. h Liver acetyl-CoA. Data are the mean ± S.E.M., and groups were compared by ANOVA with Bonferroni’s multiple comparisons test

Fig. 2

Dapagliflozin-induced increases in hepatic ketogenesis and hepatic glucose production are caused by extracellular volume depletion. a Weight change from baseline (time of injection) measured six hours after treatment. b–d Plasma epinephrine, corticosterone, and glucagon concentrations. Data are the mean ± S.E.M., with comparisons by ANOVA with Bonferroni’s multiple comparisons test. e, f Weight change and plasma glucose concentrations six hours after treatment with furosemide. g Plasma epinephrine. h Whole-body β-OHB turnover. In panels e–h, comparisons were performed using the 2-tailed unpaired Student’s t-test. Data are the mean ± S.E.M

Fig. 3

Dapagliflozin (1 mg kg⁻¹) causes ketoacidosis in a rat model of type 2 diabetes. a Weight change. b, c Plasma glucose and epinephrine concentrations. d Heart rate. e, f Whole-body fatty acid and β-OHB turnover. g Liver acetyl-CoA. h Plasma bicarbonate. In all panels, data are the mean ± S.E.M., with comparisons by ANOVA with Bonferroni’s multiple comparisons test

Fig. 4

Dapagliflozin causes ketoacidosis in normal rats through β-1 adrenergic and glucocorticoid activity. a, b Heart rate and body temperature after treatment with dapagliflozin ± atenolol ± mifepristone. c, d Whole-body fatty acid and glycerol turnover. e Liver acetyl-CoA content. f Whole-body glucose turnover. g, h Plasma β-OHB concentrations and β-OHB turnover. i Plasma bicarbonate. In all panels, data are the mean ± S.E.M., with comparisons by ANOVA with Bonferroni’s multiple comparisons test