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 5 years and if this association was modified by incident ESRD during the follow-up period. Summary of Background Data: Mortality risk in individuals with pre-dialysis 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 January 1, 2006 and September 30, 2015 (n = 802) were matched to patients who did not have surgery (n = 4933). 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 body mass index > 40kg/m 2 (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 (hazard ratio = 0.21; 95% confidence interval: 0.14-0.32; P < 0.001). Incident ESRD did not moderate the observed association between surgery and mortality (hazard ratio = 1.59; 95% confidence interval: 0.31-8.23; P =0.58).

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.