While evidence of improved renal function following gastric bypass exists, pre-operative predictors of this improvement are not completely known.
To assess the glomerular filtration rate (GFR) 1 year after Roux-en-Y gastric bypass (RYGB) and to identify pre-operative predictors associated with the improvement of renal function.
A historical cohort study, which included 109 obese patients before and 12 months after RYGB, was classified into subgroups according to GFR (normofiltration, hypofiltration (GFR < 5th percentile), and hyperfiltration (GFR > 95th percentile)). The 5th and 95th percentiles were 90 and 120 mL/min/1.73 m2, respectively. The primary outcome was the variation of GFR (%GFR) estimated by the Chronic Kidney Disease - Epidemiology Collaboration (CKD-EPI) formula, calculated using serum creatinine, ethnicity, and gender.
The mean age was 38.3 ± 10.3 years and 77% were female; 52.3% presented hypertension and 27.5% type 2 diabetes. One year after surgery, the mean BMI decreased from 36.7 ± 3.6 to 28.8 ± 3.3 kg/m2 (p < 0.001). Pre-surgically, 37.6% presented hypofiltration, 47.7% normofiltration, and 14.7% hyperfiltration. The overall GFR increased from 95.5 ± 19 to 104 ± 16.4 mL/min (10.9%) (p < 0.001). The overall post-surgical %GFR was negatively correlated with the pre-surgical GFR (R = − 0.687; p < 0.001). In the hypofiltration and normofiltration subgroups, the post-surgical %GFR was negatively correlated with age (R = − 0.328, p = 0.036; and R = − 0.355, p = 0.004, respectively) and pre-surgical GFR (R = − 0.436, p = 0.04; and R = − 0.528, p < 0.001, respectively).
RYGB led to a significant improvement in renal function, mainly among patients with a worse pre-operative renal function. In the hypofiltration and normofiltration subgroups, a younger age was associated with better outcomes.
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Chooi YC, Ding C, Magkos F. The epidemiology of obesity. Metabolism. 2019;92:6–10.
Gansevoort RT, Correa-Rotter R, Hemmelgarn BR, et al. Chronic kidney disease and cardiovascular risk: epidemiology, mechanisms, and prevention. Lancet. 2013;382(9889):339–52.
Ecder T. Early diagnosis saves lives: focus on patients with chronic kidney disease. Kidney Int Suppl. 2011;3(4):335–6.
Kopple JD. Obesity and chronic kidney disease. J Ren Nutr. 2010;20:S29–30.
Tsuboi N, Okabayashi Y, Shimizu A, et al. The renal pathology of obesity. Kidney Int Rep. 2017;2(2):251–60.
Eckardt KU, Coresh J, Devuyst O, et al. Evolving importance of kidney disease: from subspecialty to global health burden. Lancet. 2013;382(9887):158–69.
Sitticharoon C, Chatree S, Churintaraphan M. Expressions of neuropeptide Y and Y1 receptor in subcutaneous and visceral fat tissues in normal weight and obese humans and their correlations with clinical parameters and peripheral metabolic factors. Regul Pept. 2013;185:65–72.
LeRoux CW, Welbourn R, Werling M, et al. Gut hormones as mediators of appetite and weight loss after Roux-en-Y gastric bypass. Ann Surg. 2007;246(5):780–5.
LeRoux CW, Heneghan HM. Bariatric surgery for obesity. Med Clin North Am. 2018;102(1):165–82.
Chaim EA, Pareja JC, Gestic MA, et al. Pre-operative multidisciplinary program for bariatric surgery: a proposal for the Brazilian public health system. Arq Gastroenterol. 2017;54(1):70–4.
Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604–12.
Matsushita K, Mahmoodi BK, Woodward M, et al. Comparison of risk prediction using the CKD-EPI equation and the MDRD study equation for estimated glomerular filtration rate. JAMA. 2012;307:1941–51.
Okada R, Yasuda Y, Tsushita K, et al. The number of metabolic syndrome components is a good risk indicator for both early- and late-stage kidney damage. Nutr Metab Cardiovasc Dis. 2014;24(3):277–85.
Magalhães DSC, Pedro JMP, Souteiro PEB, et al. Analyzing the impact of bariatric surgery in kidney function: a 2-year observational study. Obes Surg. 2019;29(1):197–206.
Ngoh CLY, So JBY, Tiong HY, et al. Effect of weight loss after bariatric surgery on kidney function in a multiethnic Asian population. Surg Obes Relat Dis. 2016;12(3):600–5.
Favre G, Anty R, Canivet C, et al. Determinants associated with the correction of glomerular hyper-filtration one year after bariatric surgery. Surg Obes Relat Dis. 2017;13(10):1760–6.
Hou CC, Shyu RS, Lee WJ, et al. Improved renal function 12 months after bariatric surgery. Surg Obes Relat Dis. 2013;9(2):202–6.
von Scholten BJ, Persson F, Svane MS, et al. Effect of large weight reductions on measured and estimated kidney function. BMC Nephrol. 2017;18(1):52.
Bilha SC, Nistor I, Nedelcu A, et al. The effects of bariatric surgery on renal outcomes: a systematic review and meta-analysis. Obes Surg. 2018;28(12):3815–33.
Li K, Zou J, Ye Z, et al. Effects of bariatric surgery on renal function in obese patients: a systematic review and meta analysis. PLoS One. 2016;11(10):e0163907.
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Garcia, M.S., Calderoni, D.R., Jimenez, L.S. et al. Renal Function 1 Year After Bariatric Surgery: Influence of Roux-en-Y Gastric Bypass and Identification of Pre-Operative Predictors of Improvement. OBES SURG 30, 860–866 (2020). https://doi.org/10.1007/s11695-019-04249-w
- Kidney diseases
- Gastric bypass
- Bariatric surgery
- Glomerular filtration rate