Bariatric surgery is associated with improvement in kidney outcomes

Abstract

Severe obesity is associated with increased risk of kidney disease. Whether bariatric surgery reduces the risk of adverse kidney outcomes is uncertain. To resolve this wecompared the risk of estimated glomerular filtration rate (eGFR) decline of≥30% and doubling of serum creatinine or end-stage renal disease (ESRD) in 985 patients who underwent bariatric surgery with 985 patients who didnot undergo such surgery. Patients were matched ondemographics, baseline body mass index, eGFR, comorbidities, and previous nutrition clinic use. Mean agewas 45 years, 97% were white, 80% were female, and33% had baseline eGFR<90 ml/min per 1.73 m(2). Mean1-year weight loss was 40.4 kg in the surgery group compared with 1.4 kg in the matched cohort. Over a median follow-up of 4.4 years, 85 surgery patients had aneGFR decline of≥30% (22 had doubling of serum creatinine/ESRD). Over a median follow-up of 3.8 years, 177patients in the matched cohort had an eGFR decline of≥30% (50 had doubling of serum creatinine/ESRD). Inadjusted analysis, bariatric surgery patients had a significant 58% lower risk for an eGFR decline of≥30% (hazard ratio 0.42, 95% confidence interval 0.32-0.55) and57% lower risk of doubling of serum creatinine or ESRD (hazard ratio 0.43, 95% confidence interval: 0.26-0.71) compared with the matched cohort. Results were generally consistent among subgroups of patients with and without eGFR<90 ml/min per 1.73 m(2), hypertension, and diabetes. Thus, bariatric surgery may be an option to prevent kidney function decline in severely obese individuals.