Renoprotective effects of empagliflozin in type 1 and type 2 models of diabetic nephropathy superimposed with hypertension.

Diabetes, hypertension, and aging are major contributors to cardiovascular and chronic kidney disease (CKD). Sodium/glucose cotransporter 2 (SGLT2) inhibitors have become a preferred treatment for type II diabetic patients since they have cardiorenal protective effects. However, most elderly diabetic patients also have hypertension, and the effects of SGLT2 inhibitors have not been studied in hypertensive diabetic patients or animal models. The present study examined if controlling hyperglycemia with empagliflozin, or given in combination with lisinopril, slows the progression of renal injury in hypertensive diabetic rats. Studies were performed using hypertensive streptozotocin-induced type 1 diabetic Dahl salt-sensitive (STZ-SS) rats and in deoxycorticosterone-salt hypertensive type 2 diabetic nephropathy (T2DN) rats. Administration of empagliflozin alone or in combination with lisinopril reduced blood glucose, proteinuria, glomerular injury, and renal fibrosis in STZ-SS rats without altering renal blood flow (RBF) or glomerular filtration rate (GFR). Blood pressure and renal hypertrophy were also reduced in rats treated with empagliflozin and lisinopril. Administration of empagliflozin alone or in combination with lisinopril lowered blood glucose, glomerulosclerosis, and renal fibrosis but had no effect on blood pressure, kidney weight, or proteinuria in hypertensive T2DN rats. RBF was not altered in any of the treatment groups, and GFR was elevated in empagliflozin-treated hypertensive T2DN rats. These results indicate that empagliflozin is highly effective in controlling blood glucose levels and slows the progression of renal injury in both hypertensive type 1 and type 2 diabetic rats, especially when given in combination with lisinopril to lower blood pressure.