Background: Obesity is associated with a range of medical problems, including impaired renal function. Type 2 diabetes mellitus (T2DM), independently, exerts a direct and multifactorial impact on renal health. This study evaluates and compares the effects of metabolic bariatric surgery (MBS) on renal function in patients with and without T2DM.
Methods: This prospective cohort study followed patients undergoing MBS over three years, stratified by T2DM status. Participants were matched using propensity scores (PS), and postoperative trajectories of creatinine-based estimated glomerular filtration rate (eGFR) were compared. Generalized estimating equation (GEE) method was employed to identify factors significantly associated with changes in eGFR over time.
Results: A total of 1895 participants (83% women), including 770 PS-matched individuals, were enrolled in the study. All participants had a baseline eGFR ≥ 60 mL/min/1.73m2. Across both unmatched and matched cohorts, and irrespective of T2DM status, eGFR improved over the three-year follow-up, with no significant between-group differences or interactions observed. Multivariable analysis identified older age, being a woman, higher baseline eGFR, and undergoing sleeve gastrectomy (SG) as negative correlates of eGFR improvements over time.
Conclusion: Renal function improved following MBS, regardless of T2DM status. Furthermore, older age, being a woman, higher baseline eGFR, and undergoing SG were associated with less eGFR improvements.
Keywords: Diabetes; Metabolic bariatric surgery; Obesity; Renal function.
© 2026. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.