243-OR: ADA Presidents' Select Abstract: Dapagliflozin Reduces Measured GFR by Reducing Renal Efferent Arteriolar Resistance in Type 2 Diabetes

Introduction: Sodium-glucose cotransporter-2 inhibitors (SGLT2is) improve hard renal outcomes in type 2 diabetes (T2D) patients. An acute and reversible drop in eGFR that stabilizes over time, as with RAS inhibitors, suggests involvement of a beneficial renal hemodynamic mechanism. In hyperfiltering T1D patients, SGLT2i lowered GFR by increasing afferent arteriolar resistance, possibly by activating tubuloglomerular feedback. We studied the renal hemodynamic effects of SGLT2i dapagliflozin in T2D patients like those included in recent outcome trials. Methods: Forty-four T2D patients on metformin monotherapy, (62.9±7.0 years, HbA1c 7.38±0.63%, GFR 113±19 mL/min) were randomized to 12 weeks dapagliflozin 10mg (DAPA, n=24) or gliclazide 30mg (GLIC, n=20) QD to achieve glycemic equipoise. At baseline and week 12, GFR and renal plasma flow (RPF) were measured by gold-standard inulin and para-aminohippurate clearances. The measurements were performed 1) in the fasting state, 2) during clamped euglycemia (90 mg/dL) and 3) hyperglycemia (270 mg/dL). Renal vascular resistance (RVR) and filtration fraction (FF) were calculated using GFR, RPF, Ht and MAP. Afferent and efferent arteriolar resistances were estimated by Gomez’ equations. Results: HbA1C decreased similarly (0.47% with DAPA and 0.65% with GLIC; p=ns), while only DAPA significantly reduced MAP by approximately 6 mmHg. DAPA reduced GFR during all three conditions by 8.9 (p Conclusion: We confirm that SGLT2i induces beneficial renal hemodynamic changes in T2D beyond glycemic control that are characterized by reduced GFR and FF. However, in contrast to standing opinion, this is mediated by efferent arteriolar dilation rather than afferent arteriolar constriction. Disclosure E.J. van Bommel: None. M.A. Muskiet: Consultant; Self; Eli Lilly and Company, Novo Nordisk A/S, Sanofi. M.J. van Baar: None. M.H. Kramer: None. M. Nieuwdorp: Advisory Panel; Self; Caelus health. J.A. Joles: None. D.H. van Raalte: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Merck Sharp & Dohme Corp., Sanofi. Research Support; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Merck Sharp & Dohme Corp., Sanofi. Funding AstraZeneca Nederland BV