Bariatric Surgery and Long-term Survival in Patients With Obesity and End-stage Kidney Disease.

Importance: Obesity rates in patients with end-stage kidney disease are rising, contribute to excess morbidity, and limit access to kidney transplant. Despite this, there continues to be controversy around the use of bariatric surgery in this patient population. Objective: To determine whether bariatric surgery is associated with improvement in long-term survival among patients with obesity and end-stage kidney disease. Design, Setting, and Participants: Retrospective cohort study and secondary analysis of previously collected data from the United States Renal Data System registry (2006-2015). We used Cox proportional hazards analysis to evaluate differences in outcomes for patients receiving bariatric surgery (n = 1597) compared with a matched cohort of nonsurgical patients (n = 4750) receiving usual care. Data were analyzed between September 3, 2019, and November 13, 2019. Exposure: Receipt of bariatric surgery. Main Outcomes and Measures: All-cause mortality at 5 years. Secondary outcomes included disease-specific mortality and incidence of kidney transplant. Results: Surgical and nonsurgical control patients had similar age, demographics, and comorbid disease burden. The mean (SD) age was 49.8 (11.2) years for surgical patients vs 51.7 (11.1) years for nonsurgical patients. Six hundred fifteen surgical patients (38.5%) were black vs 1833 nonsurgical patients (38.6%). Surgery was associated with lower all-cause mortality at 5 years compared with usual care (cumulative incidence, 25.6% vs 39.8%; hazard ratio, 0.69, 95% CI, 0.60-0.78). This was driven by lower mortality from cardiovascular causes at 5 years for patients undergoing bariatric surgery compared with nonsurgical control patients (cumulative incidence, 8.4% vs 17.2%; hazard ratio, 0.51; 95% CI, 0.41-0.65). Bariatric surgery was also associated with an increase in kidney transplant at 5 years (cumulative incidence, 33.0% vs 20.4%; hazard ratio, 1.82; 95% CI, 1.58-2.09). However, at 1 year, bariatric surgery was associated with higher all-cause mortality compared with usual care (cumulative incidence, 8.6% vs 7.7%; hazard ratio, 1.45; 95% CI, 1.13-1.85). Conclusions and Relevance: Among patients with obesity and end-stage kidney disease, bariatric surgery was associated with lower all-cause mortality compared with usual care. Bariatric surgery was also associated with an increase in kidney transplant. Bariatric surgery may warrant further consideration in the treatment of patients with obesity and end-stage kidney disease.