#1679 Relationship between initial eGFR DIP with proteinuria after SGLT2i treatment, in patients with IgA nephropathy. A real-world clinical study

Abstract Background and Aims Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with better cardiovascular outcomes and with nephroprotection independent of diabetes status. Recent data suggest that SGLT2i significantly reduce proteinuria in patients with IgA nephropathy (IgAN). However, they often cause an initial decline in estimated glomerular filtration rate (eGFR). The aim of our study was to assess the degree of proteinuria reduction after SGLT2i treatment in IgAN and its possible association with the initial functional dip in eGFR. Method 63 adult patients with biopsy-proven IgA nephropathy, eGFR ≥ 30 mL/min/1.73 m2 (CKD-epi), and total urine protein of 0.5 grams/day at screening were included. Patients with secondary IgAN were excluded. All receiving maximally tolerated RASi for at least 12 weeks. All patients started dapagliflozin 10 mg once per day after baseline data were registered. The total follow-up was 12 months. The main outcome was the decline in eGFR and the reduction in 24-hour proteinuria from SGLT2i initiation to 1,3, 6, 9, 12 months, end-stage renal disease, or kidney or cardiovascular death. Results 55 patients (38/17 M/F), with mean age of 44,2±18,3 years, completed follow up. 8 patients discontinued treatment due to adverse events attributed to dapagliflozin. At baseline eGFR was 66.17±19,7 ml/min/1.73 m2 and Upr: 2356±1023 mg/24H. There was a transient decline in eGFR, 30 days after initiation of dapagliflozin (66.17±19,7 min/1.73 m2 at baseline to 57 ml/min/1.73 m2) but then, there was an improvement at month 3 from baseline. The Upr/24H difference for dapagliflozin was −25.1% (95% CI −27.5, −23.2; p 0.001) at the end of follow-up (month 12). Proteinuria reduction was similar across all eGFRs. Notably, a significant correlation was found between the initial eGFR dip and percentage proteinuria reduction in the 12th month. (R = –0.23; p = 0.03). Consistent results of dapagliflozin treatment on proteinuria were found in all analysis subgroups including sex, baseline proteinuria, systolic blood pressure, and body mass index. No hypoglycaemic events were reported and no deaths occurred. Conclusion In the present study, the use of SGLT2i was associated with a significant reduction of proteinuria in patients with IgA nephropathy in patients with maximally tolerated RASi. Higher initial eGFR dip after treatment initiation was a predictor of a significantly higher reduction in proteinuria at the end of follow-up. The correlation between eGFR dip and proteinuria reduction perhaps reflects the intraglomerular pressure reduction, mediated by tubuloglomerular feedback, one of the numerous.