Abstract
INTRODUCTION: Obesity is associated with chronic kidney disease (CKD) incidence and progression. We examined whether bariatric surgery is associated with change in eGFR trajectory among patients with and without CKD. METHODS: Patients who underwent bariatric surgery at two health systems were identified using ICD-9/ICD-10 and CPT codes. Linear mixed models were fit on estimated glomerular filtration rate (eGFR) trajectory pre- and post-surgery among patients with or without CKD. Models were adjusted for age, sex, race, ethnicity, body mass index, hypertension, diabetes, follow-up duration, and type of bariatric surgery. Post-surgery, eGFR trajectory among patients with CKD was also compared following 1:2 propensity score matching to (1) patients without CKD who underwent surgery and (2) patients with CKD who did not undergo surgery. RESULTS: Patients with CKD (n = 139) at Michigan Medicine had a slower annual rate of eGFR decline post-surgery compared to patients without CKD (n = 278) (1.54 [-2.26, -0.81] vs. 3.15 [-3.41, -2.87] mL/min/1.73 m2; p < 0.001), despite adjusting for degree of weight loss. Among patients with CKD, surgery was associated with a slower annual rate of eGFR decline (-0.20 [-0.83, 0.43] post-surgery vs. -1.11 [-1.37, -0.85] mL/min/1.73 m2 for non-surgery patients; p < 0.001). In an external validation study of patients with CKD in the Providence health system, bariatric surgery predicted an average increase in annualized eGFR slope by 1.19 [0.12, 2.25] mL/min/1.73 m2 (p = 0.03). CONCLUSION: Bariatric surgery is associated with less eGFR decline and may have weight-independent effects on preserving kidney function among persons living with obesity and CKD.