Singh, Balwinder

ABSTRACT Introduction Sodium‐glucose cotransporter‐2 inhibitors (SGLT2i), initially developed for type 2 diabetes, have shown promise in improving renal outcomes in patients with and without diabetes. However, their effect on lithium‐associated kidney dysfunction remains unknown. Methods This historical cohort study included patients from Mayo Clinic (2001–2023) with mood disorders who received lithium for ≥ 6 months and later used SGLT2i for ≥ 1 month. Data on SGLT2i use and lithium treatment were extracted from electronic health records. Serum creatinine values were used to calculate estimated glomerular filtration rate (eGFR) trajectories. Linear mixed‐effects models with piecewise linear splines were used to estimate eGFR slopes before and after SGLT2i initiation, adjusted for age and sex. Results Fifty‐six patients (mean age 57.4 years, 46.4% female), predominantly with bipolar disorder (87.5%), were included. The mean eGFR, measured nearest to SGLT2i initiation, was 77.9 ± 26.0 mL/min/1.73 m 2 , and the mean duration of SGLT2i use was 19.5 ± 17.8 months. Before SGLT2i initiation, eGFR declined at a rate of −1.43 mL/min/1.73 m 2 per year ( p < 0.001). After initiation, eGFR increased by 0.69 mL/min/1.73 m 2 per year, reflecting a + 2.13 change ( p = 0.025). Sensitivity analyses, including only patients on lithium at SGLT2i initiation ( n = 22) or who had > 1 year of SGLT2i use ( n = 29) showed similar, though non‐significant, changes in slopes. Conclusion SGLT2i treatment was associated with a significant improvement in eGFR trajectory in patients with mood disorders who received long‐term lithium therapy. These findings suggest a potential role for SGLT2is in mitigating lithium‐associated kidney dysfunction and highlight the need for randomized controlled trials in this population.