Impact of Bariatric Metabolic Surgery on Cardiovascular, Kidney, and Mortality Outcomes Among Adults with Obesity and Chronic Kidney Disease Across Different Time Frames

Abstract

Objective: Bariatric metabolic surgery (BMS) is an effective intervention for obesity, with proven benefits in reducing cardiovascular events and mortality. However, its impact on patients with chronic kidney disease (CKD) remains unclear. This study aims to evaluate the long-term outcomes of BMS compared to nonsurgical management in CKD patients with obesity, focusing on major adverse cardiovascular events (MACE), major adverse kidney events (MAKE), and all-cause mortality.

Methods: We conducted a retrospective cohort study using the TriNetX database, including adult patients with CKD and obesity. Patients who underwent BMS (Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy) were compared to those receiving lifestyle interventions. Propensity score matching (PSM) was applied to balance baseline characteristics. The primary outcome was a composite of all-cause mortality, MACE, and MAKE. Secondary outcomes included individual components of the primary outcome. Cox proportional hazards models and Kaplan-Meier survival analyses were used to assess outcomes across short-term (1 month-1 year), intermediate (up to 3 years), and long-term (up to 5 years) follow-up periods. Subgroup analyses were conducted by CKD stage (1-3 vs. 4-5) to evaluate effect heterogeneity across different levels of kidney function.

Results: After matching, 5,221 patients were included in each group. Over a 5-year follow-up, BMS was associated with significantly lower risk of the primary composite outcome (HR 0.75, 95% CI 0.70-0.81; p < 0.001). Subgroup analyses showed that this protective effect was observed across all CKD stages, with a more pronounced reduction in MAKE among patients with advanced CKD (stages 4-5) compared to early-stage CKD (stages 1-3). BMS was also associated with greater preservation of eGFR over time compared to controls.

Conclusion: Among adults with obesity and CKD, BMS was associated with lower risks of mortality, MACE, and MAKE, as well as slower decline in kidney function. The benefits were consistent across CKD stages and appeared particularly pronounced in patients with advanced CKD (stages 4-5), highlighting the potential role of BMS in high-risk kidney populations. Further randomized trials are needed to validate these results and refine patient selection criteria.

Keywords: Bariatric metabolic surgery; Chronic kidney disease; Major adverse cardiovascular events; Major adverse kidney events; Obesity.