Renal, metabolic and cardiovascular considerations of SGLT2 inhibition

The kidney has a pivotal role in maintaining glucose homeostasis by using glucose as a metabolic fuel, by producing glucose through gluconeogenesis, and by reabsorbing all filtered glucose through the sodium-glucose cotransporters SGLT1 and SGLT2 located in the proximal tubule. In patients with diabetes, the maximum glucose reabsorptive capacity (Tm_G) of the kidney, as well as the threshold for glucose spillage into the urine, are elevated, contributing to the pathogenesis of hyperglycaemia. By reducing the Tm_G and, more importantly, the threshold of glucosuria, SGLT2 inhibitors enhance glucose excretion, leading to a reduction in fasting and postprandial plasma glucose levels and improvements in both insulin secretion and insulin sensitivity. The beneficial effects of SGLT2 inhibition extend beyond glycaemic control, however, with new studies demonstrating that inhibition of renal glucose reabsorption reduces blood pressure, ameliorates glucotoxicity and induces haemodynamic effects that lead to improved cardiovascular and renal outcomes in patients with type 2 diabetes mellitus. In this Review we examine the role of SGLT2 and SGLT1 in the regulation of renal glucose reabsorption in health and disease and the effect of SGLT2 inhibition on renal function, glucose homeostasis, and cardiovascular disease.