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Kidney Week

Abstract: TH-PO455

Long-Term Impact of Bariatric Surgery on Renal Outcomes at a Community-Based Publicly Funded Bariatric Program

Session Information

Category: CKD (Non-Dialysis)

  • 2102 CKD (Non-Dialysis): Clinical, Outcomes, and Trials


  • Mcisaac, Mark, University of Saskatchewan, Oakville, Ontario, Canada
  • Jafari, Maryam, RQHR- Research and Performance Support, Regina, Saskatchewan, Canada
  • Prasad, Bhanu, RQHR, Regina, Saskatchewan, Canada

Obesity is recognized as an independent risk factor for chronic kidney disease (CKD) through multiple direct and indirect biological pathways. Bariatric surgery is a proven, effective method for sustained weight loss. However, there is a relative paucity of data on the impact of bariatric surgery on renal outcomes.


471 consecutive obese adult patients who underwent bariatric surgery between 2008-2015 were included in this observational retrospective cohort study. The patients were followed for two years post surgery at the Provincial Bariatric Surgery Clinic, Regina General Hospital, Saskatchewan. The primary objective was to evaluate the change in urine albumin/creatinine ratio (ACR) at the time of surgery and at 12 months post procedure. Secondary objectives were to determine the changes in ACR at (6 and 24 months), estimated glomerular filtration rate (eGFR) (6, 12 and 24 months), and HbA1c (12 and 24 months) post procedure.The change in body mass index (BMI), and metabolic outcomes (fasting glucose, total cholesterol, LDL, triglycerides, HbA1c) were also measured.


Patients were predominantly female (81%) with a mean age (±SD) of 46 ± 10 years. The majority of patients (87%) had a BMI >40 kg/m2 and 81 % of the patients underwent Roux-en-Y gastric bypass. The mean BMI decreased from 47.7 ± 7.8 kg/m2 at baseline to 37.1 ± 7.9 kg/m2 at 6 months and 34.8 ± 8.8 kg/m2 at 12 months. In patients with microalbuminuria, ACR showed an improvement from a median [IQR] value of 5.1 [3.7-7.5] mg/mmol at baseline to 2.3 [1.2-3.6] mg/mmol at 6 months (p=0.007), to 1.4 [0.9-3.7] mg/mmol at 2-year follow-up (p < 0.001). Similarly, eGFR increased in patients with microalbuminuria from 109 ± 10 mL/min/1.73m2 at baseline to 120 ± 36 mL/min/1.73m2 at two-year follow-up (p=0.013). There were statistically significant reductions in triglycerides, fasting glucose, and HbA1c.


The results of our study suggest bariatric surgery significantly decreased weight and consequently improved renal outcomes. There was a significant improvement in albumin excretion rates and improvement in filtration rates. An improvement in metabolic outcomes was also seen
(fasting glucose, cholesterol, and triglycerides) in patients with elevated BMI.