Survival benefit in bariatric surgery kidney recipients may be mediated through effects on kidney graft function and improvement of co-morbidities: A case-control study

Abstract

BackgroundData on the benefits of bariatric surgery for morbid obesity among kidney transplant recipients are scarce. ObjectiveTo examine the effect of bariatric surgery on graft function and survival and on obesity-related co-morbidities. SettingUniversity hospital. MethodsThis case-control study used retrospectively collected data of all kidney recipients who underwent bariatric surgery in our institution between November 2011 and August 2016 (n = 30, 11 females). Nonbariatric operated kidney recipients matched for age, sex, and time elapsed since transplantation served as controls (n = 50, 23 females). Main outcomes were renal function, graft loss events, mortality, and obesity-related co-morbidities. ResultsThe mean follow-up duration was 2.4 ± 1.3 years for both groups. At final follow-up, there was an increase in estimated glomerular filtration rates for the bariatric surgery group, and a decrease for the controls (13.4 ± 19.9 and −3.9 ± 15.8 mL/min/1.73 m2, respectively, P < .001). The chronic kidney disease classification improved in 9 bariatric surgery group patients and in 6 controls (P = .1). Two patients in the bariatric surgery group and 6 controls died. Total death or graft function loss during the follow-up was 6.7% and 16.7%, respectively (P = .3). The total numbers of co-morbidities and medications were lower in the bariatric surgery patients (−.7 and −2, respectively) and higher in the controls (+.3 and +1.1; P < .001) at study closure. ConclusionsThere was an improvement in renal function, graft survival, and obesity-related co-morbidities among kidney transplant recipients who underwent bariatric surgery compared with those who did not. These findings support bariatric surgery in this population and warrant prospective studies.