Favorable changes in the eGFR slope after dapagliflozin treatment and its association with the initial dip.

Background: Renoprotective effects of sodium glucose transporter 2 (SGLT2) inhibitors, including dapagliflozin, were observed in randomized controlled trials (RCTs). The suspected underlying mechanism is a correction of hyperfiltration, observed as an "initial dip". Whether SGLT2 inhibitors can attenuate the rate of decline in the estimated glomerular filtration rate (eGFR) in clinical settings, even when considering the pre-treatment decline rate, is unknown. Although several RCTs identified an association between the initial dip and long-term renal prognoses, a conclusion has not been reached.

Methods: We collected the eGFR data of patients for whom dapagliflozin was initiated in our hospital and then calculated their eGFR slopes before and after the start of the treatment. We investigated the changes in the eGFR slopes (ΔeGFR slope) and the association between the ΔeGFR slope and the initial dip. Risks for rapid eGFR decliners (eGFR slope < - 3 mL/min/1.73 m²/year) were also examined.

Results: The eGFR slope was significantly milder after dapagliflozin treatment (p < 0.01). A deeper initial dip was associated with a milder rate of eGFR decline (adjusted beta: - 0.29, p < 0.001). Dapagliflozin treatment reduced the proportion of rapid eGFR decliners from 52.9 to 14.7%, and a smaller initial dip was identified as a significant risk for post-treatment rapid eGFR decline (adjusted odds ratio: 1.73, p < 0.05).

Conclusions: Compared to before the administration of dapagliflozin, the rate of eGFR decline was significantly milder after its administration. The initial dip was significantly associated with long-term renoprotective effects and may be a useful predictor of treatment response.