Dataset Information

Measurement of glomerular filtration rate in patients undergoing obesity surgery.

ABSTRACT: BACKGROUND:Most studies on obesity surgery have measured renal function using the estimated GFR. However, due to the reduction of muscle mass, and therefore creatinine that accompanies weight loss, such measures can falsely suggest an improvement in renal function. To balance the risks of surgery versus any potential benefits on renal function, we need to be able to determine renal function using valid and reliable methodologies. In this pilot study we aimed to measure renal function in patients with CKD undergoing obesity surgery using the gold standard 51Cr-EDTA GFR clearance methodology which is independent of measures of muscle mass. METHODS:Nine consecutive obese patients with CKD underwent obesity surgery. Their renal function was assessed using 51Cr-EDTA GFR, cystatin C and serum creatinine as well as using eGFR equations including MDRD CKD Epi, Cockcroft Gault and CKD Epi cystatin before and 12?months after surgery. RESULTS:Renal function using the 51Cr-EDTA measured GFR did not change significantly after surgery. Similar results were obtained when Cystatin C, CKD Epi cystatin, CKD Epi cystatin creatinine and adjusted Cockcroft Gault Creatinine clearance methods were used. In contrast there were either trends or significant improvements in renal function measured using the MDRD and CKD Epi equations. CONCLUSIONS:In this pilot study using the gold standard 51Cr-EDTA method we found stabilisation in renal function after obesity surgery. Until further definitive data emerge it is critical to balance the risk and benefits of surgery, especially if renal function may not improve as often as previously suggested. TRIAL REGISTRATION:ClinicalTrials.gov NCT01507350 . Registered June 2011.

SUBMITTER: Chuah LL

PROVIDER: S-EPMC6311002 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Measurement of glomerular filtration rate in patients undergoing obesity surgery.

Chuah Ling L LL Miras Alexander D AD Perry Laura M LM Frankel Andrew H AH Towey David J DJ Al-Mayahi Zahraa Z Svensson William W le Roux Carel W CW

BMC nephrology 20181229 1

<h4>Background</h4>Most studies on obesity surgery have measured renal function using the estimated GFR. However, due to the reduction of muscle mass, and therefore creatinine that accompanies weight loss, such measures can falsely suggest an improvement in renal function. To balance the risks of surgery versus any potential benefits on renal function, we need to be able to determine renal function using valid and reliable methodologies. In this pilot study we aimed to measure renal function in ...[more]

PMID: 30594245

Similar Datasets

Project description:PurposeTo assess the accuracy of glomerular filtration rate (GFR) measurements obtained with low-contrast agent dose dynamic contrast material-enhanced magnetic resonance (MR) renography in patients with liver cirrhosis who underwent routine liver MR imaging, with urinary clearance of technetium 99m ((99m)Tc) pentetic acid (DTPA) as the reference standard.Materials and methodsThis HIPAA-compliant study was institutional review board approved. Written informed patient consent was obtained. Twenty patients with cirrhosis (14 men, six women; age range, 41-70 years; mean age, 54.6 years) who were scheduled for routine 1.5-T liver MR examinations to screen for hepatocellular carcinoma during a 6-month period were prospectively included. Five-minute MR renography with a 3-mL dose of gadoteridol was performed instead of a routine test-dose timing examination. The GFR was estimated at MR imaging with use of two kinetic models. In one model, only the signal intensities in the aorta and kidney parenchyma were considered, and in the other, renal cortical and medullary signal intensities were treated separately. The GFR was also calculated by using serum creatinine levels according to the Cockcroft-Gault and modification of diet in renal disease (MDRD) formulas. All patients underwent a (99m)Tc-DTPA urinary clearance examination on the same day to obtain a reference GFR measurement. The accuracies of all MR- and creatinine-based GFR estimations were compared by using Wilcoxon signed rank tests.ResultsThe mean reference GFR, based on (99m)Tc-DTPA clearance, was 74.9 mL/min/1.73 m(2) ± 27.7 (standard deviation) (range, 10.3-120.7 mL/min/1.73 m(2)). With both kinetic models, 95% of MR-based GFRs were within 30% of the reference values, whereas only 40% and 60% of Cockcroft-Gault- and MDRD-based GFRs, respectively, were within this range. MR-based GFR estimates were significantly more accurate than creatinine level-based estimates (P < .001).ConclusionGFR assessment with MR imaging, which outperformed the Cockcroft-Gault and MDRD formulas, adds less than 10 minutes of table time to a clinically indicated liver MR examination without ionizing radiation.Supplemental materialhttp://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101338/-/DC1.

Project description:Rationale & objectiveEvaluation of glomerular filtration rate (GFR) is challenging in adults undergoing bariatric surgery because creatinine and cystatin C levels are influenced by changes in muscle and fat mass. Additionally, indexing of GFR by body surface area (BSA) may by affected by decreases in BSA.Study designProspective observational study.Setting & participants27 adults with body mass index (BMI) ≥ 35 kg/m2 who underwent measurement of GFR before and after bariatric surgery.OutcomesIndexed and nonindexed GFRs measured (mGFRs) using plasma iohexol clearance, indexed and nonindexed estimated GFR (eGFR) based on levels of creatinine, cystatin C, or both from Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations.Analytic approachBias and percent of estimates within 20% and 30% of mGFR (P20 and P30) for estimating equations were examined.ResultsMean presurgery BMI was 49.5 (SD, 9.4) kg/m2, BSA was 2.42 (SD, 0.27) m2, nonindexed mGFR was 117.3 (SD, 34.1) mL/min, and indexed mGFR was 84.1 (SD, 22.0) mL/min/1.73 m2. After 6 months, mean BMI changed by -13.8 (95% CI, -15.9 to -11.8) kg/m2, BSA by -0.30 (95% CI, -0.33 to -0.27) m2, and nonindexed mGFR by -9.2 (95% CI, -17.2 to -1.1) mL/min, while indexed mGFR was unchanged at 5.1 (95% CI, -0.1 to 10.4) mL/min/1.73 m2. Nonindexed eGFRcr was unbiased (median bias, 5.0 [95% CI, -4.3 to 11.6] mL/min) before surgery, but overestimated mGFR (8.8 [95% CI, 1.8 to 16.9] mL/min) after surgery. Nonindexed eGFRcys underestimated mGFR before (median bias, -12.1 [95% CI, -21.4 to -1.2] mL/min) and after surgery (-11.2 [95% CI, -21.8 to -7.3] mL/min). Nonindexed eGFRcr-cys was unbiased before (median bias, -6.0 [95% CI, -11.0 to 1.0] mL/min) and after surgery (-2.0 [95% CI, -8.8 to 4.9] mL/min). Findings were similar for indexed eGFR compared with indexed mGFR.LimitationsSmall, mostly white sample.ConclusionsChanges in indexed and nonindexed GFRs may be discordant after bariatric surgery in adults because of decreases in BSA. Indexed and nonindexed eGFRcr-cys may be less biased than indexed or nonindexed eGFRcr or eGFRcys because of opposite biases in estimating mGFR.

Dataset Information

Measurement of glomerular filtration rate in patients undergoing obesity surgery.

Publications

Measurement of glomerular filtration rate in patients undergoing obesity surgery.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets