Impact of sodium–glucose cotransporter 2 inhibitors on renal function in participants with type 2 diabetes and chronic kidney disease with normoalbuminuria

BACKGROUND: We compared the effects of sodium–glucose cotransporter 2 (SGLT2) inhibitors on renal function in participants with type 2 diabetes and chronic kidney disease (CKD) classified by degree of albuminuria. METHODS: A retrospective review of the clinical records of Japanese participants with type 2 diabetes (age > 20 years; SGLT2 inhibitor treatment > 2 years; estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2)) was conducted. Based on the urinary albumin-to-creatinine ratio (UACR) or urinary protein-to-creatinine ratio (UPCR) at the start of SGLT2 inhibitor administration, participants were categorized into three groups: normoalbuminuria (A1; UACR < 30 mg/g Cr or UPCR < 0.15 g/g Cr), microalbuminuria (A2; UACR 30 to < 300 mg/g Cr or UPCR 0.15 to < 0.50 g/g Cr), and macroalbuminuria (A3; UACR ≥ 300 mg/g Cr or UPCR ≥ 0.50 g/g Cr). The study outcome was a comparison of the rates of change in renal function evaluated by eGFR at 2 years after starting SGLT2 inhibitor among the three groups. RESULTS: A total of 87 participants (40 females, 47 males) were categorized into three groups: A1 (n = 46), A2 (n = 25), and A3 (n = 16). eGFR was similarly decreased at 2 years before starting SGLT2 inhibitor in all three groups. However, the decline in eGFR was ameliorated at 2 years after starting SGLT2 inhibitor, and eGFR was rather increased in the A1 and A2 groups. Interestingly, the rate of change in eGFR at 2 years after starting SGLT2 inhibitor in the A1 group was significantly higher than that in the A3 group. CONCLUSIONS: These results demonstrate that more favorable effects of SGLT2 inhibitors on renal function were observed in participants with type 2 diabetes and CKD with normoalbuminuria compared with those with macroalbuminuria. Trial registration UMIN-CTR: UMIN000035263. Registered 15 December 2018