Measuring the Glomerular Filtration Rate in Obese Individuals without Overt Kidney Disease
Open Access
- 2 July 2010
- journal article
- research article
- Published by S. Karger AG in Nephron Clinical Practice
- Vol. 116 (3), c224-c234
- https://doi.org/10.1159/000317203
Abstract
Background: Identifying methods to accurately measure the glomerular filtration rate (GFR) in obese individuals without kidney overt kidney disease is necessary to understanding the pathophysiology and natural history of obesity-related kidney disease. Methods: Using a cross-sectional design, iohexol clearance and disposition was measured, an optimal sampling schedule was identified, and the reliability of GFR-estimating methods was described in 29 obese individuals with normal serum creatinine levels. Iohexol disposition was measured using population pharmacokinetics. The agreement with GFR-estimating equations was assessed by intraclass coefficients. Results: Mean age was 44 ± 10 years, body mass index 45 ± 10, creatinine 0.7 ± 0.2 mg/dl (62 ± 18 µmol/l) , and cystatin C 0.83 ± 0.18 mg/dl (8.3 ± 1.8 mg/l). Iohexol disposition fit a two-compartment model and 5 sampling windows were identified over a 4-hour period to optimize model accuracy and minimize blood draws. Precision was not compromised with this sampling design. Neither creatinine nor cystatin C were linearly correlated with the measured GFR though cystatin C was independent of body composition. Agreement was fair to poor between the measured GFR and GFR-estimating equations. Conclusion: This study offers a rigorous method to study obesity-related kidney disease and improve upon suboptimal GFR-estimating methods.Keywords
This publication has 41 references indexed in Scilit:
- Population Pharmacokinetics II: Estimation MethodsAnnals of Pharmacotherapy, 2004
- Population Pharmacokinetics I: Background, Concepts, and ModelsAnnals of Pharmacotherapy, 2004
- HypothesisJournal of Hypertension, 2004
- Estimation of glomerular filtration rate in paediatric cancer patients using 51CR-EDTA population pharmacokineticsBritish Journal of Cancer, 2004
- Optimal Sampling Strategies to Assess Inulin Clearance in Children by the Inulin Single-Injection MethodClinical Chemistry, 2003
- Body composition assessment in extreme obesity and after massive weight loss induced by gastric bypass surgeryAmerican Journal of Physiology-Endocrinology and Metabolism, 2003
- Plasma clearance of a new contrast agent, iohexol: a method for the assessment of glomerular filtration rate.1984
- Human Pharmacokinetics of IohexolInvestigative Radiology, 1983
- Estimation of population characteristics of pharmacokinetic parameters from routine clinical dataJournal of Pharmacokinetics and Biopharmaceutics, 1977
- Prediction of Creatinine Clearance from Serum CreatinineNephron, 1976