Empagliflozin Dosage and Albuminuria Reduction in CKD

Background: Exploratory analysis from EMPA-REG trial revealed empagliflozin significantly reduces albuminuria compared to placebo. Yet, no study has examined if there's a correlation between albuminuria reduction and varying dosage. Methods: We conducted a retrospective study on CKD patients with UACR > 30 mg/g, dividing them into two groups: group one received empagliflozin 10 mg daily and group 2 received empagliflozin 25 mg daily, with primary goal of assessing the proportion of patients achieving >50% reduction in UACR from baseline. Results: 163 patients were included, 94 (58%) were on group 1 with mean eGFR 43.2 ml/min per 1.73m2 and median UACR 399 mg/g, and 69 (42%) were on group 2 with mean eGFR 51.0 ml/min per 1.73m2 and median UACR 666 mg/g. At baseline, 126 (77.3.%) were on RAAS blockade, and 131 (80.3%) had type 2 diabetes. After 6 months, a reduction of > 50% in albuminuria was noted in 46% of patients in group 1, while in group 2, this figure rose to 68% [with a p-value of 0.01 and an OR of 2.46 (95% CI: 1.24 to 4.9)] (Figure 1A). When we looked at percent albuminuria reduction adjusted for baseline covariates, despite noting a greater reduction in group 2 (54%, 95% CI 41 to 67) compared to group 1 (45%, 95% CI 36 to 55), the difference was 9.2% (95% CI: -0.16 to 22.7) and was not statistically significant (Figure 1B). At 6-months, the mean difference in eGFR was –2 ml/min per 1.73m2 (SD 5.7) in group 1 and -2.7 ml/min per 1.73m2 (SD 7.7) in group 2, with no discernible variance between the two groups following adjustment for baseline eGFR and baseline covariates [the difference was -0.38 (95% CI: -2.49 to 1.74)]. At 6-months, the average difference in serum potassium was –0.1 mmol/L (SD 0.4) in both groups with no difference between the two groups after adjustment for baseline serum potassium level and baseline covariates [0.00 (95% Cl: -0.11 to 0.11]. Conclusion: Higher dose of empagliflozin led to more reduction in albuminuria among CKD patients, without a significant change in eGFR or serum potassium levels compared to the lower dose.