Bariatric Surgery and Risk of Death in Persons with Chronic Kidney Disease

OBJECTIVE A retrospective cohort study investigated the association between having surgery and risk of mortality for up to five years and if this association was modified by incident End Stage Renal Disease (ESRD) during the follow-up period. SUMMARY BACKGROUND DATA Mortality risk in individuals with pre-dialysis chronic kidney disease (CKD) is high and few effective treatment options are available. Whether bariatric surgery can improve survival in people with CKD is unclear. METHODS Patients with class II and III obesity and pre-dialysis CKD stages 3 - 5 who underwent bariatric surgery between 1/1/2006 and 9/30/2015 (n = 802) were matched to patients who did not have surgery (n = 4,933). Mortality was obtained from state death records and ESRD was identified through state-based or healthcare system-based registries. Cox regression models were used to investigate the association between bariatric surgery and risk of mortality and if this was moderated by incident ESRD during the follow-up period. RESULTS Patients were primarily women (79%), non-Hispanic White (72%), under 65 years old (64%), who had a BMI ≥ 40 kg/m2 (59%), diabetes (67%) and hypertension (89%). After adjusting for incident ESRD, bariatric surgery was associated with a 79% lower 5-year risk of mortality compared to matched controls (HR = 0.21; 95% CI: 0.14-0.32; p < .001). Incident ESRD did not moderate the observed association between surgery and mortality (HR = 1.59; 95% CI 0.31-8.23; p = .58). CONCLUSIONS Bariatric surgery is associated with a reduction in mortality in pre-dialysis patients regardless of developing ESRD. These findings are significant because patients with CKD are at relatively high risk for death with few efficacious interventions available to improve survival.