title: Measurement of glomerular filtration rate in obese patients: pitfalls and potential consequences on drug therapy.
abstract: Epidemiological studies have shown that obesity is associated with chronic kidney disease and end stage renal disease. These studies have used creatinine derived equations to estimate glomerular filtration rate (GFR) and have indexed GFR to body surface area (BSA). However, the use of equations using creatinine as a surrogate marker of glomerular filtration and the indexation of GFR for BSA can be questioned in the obese population. First, these equations lack precision when they are compared to gold standard GFR measurements such as inulin clearances; secondly, the indexation of GFR for 1.73 m(2) of BSA leads to a systematic underestimation of GFR compared to absolute GFR in obese patients who have BSA that usually exceed 1.73 m(2). Obesity is also associated with pathophysiological changes that can affect the pharmacokinetics of drugs. The effect of obesity on both renal function and drug pharmacokinetics raises the issue of correct drug dosage in obese individuals. This may be particularly relevant for drugs known to have a narrow therapeutic range or excreted by the kidney.
authors.affiliation: Service of Nephrology and Hypertension, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: Grégoire
authors.initials: G
authors.lastname: Wuerzner
authors.forename: Murielle
authors.initials: M
authors.lastname: Bochud
authors.forename: Vittorio
authors.initials: V
authors.lastname: Giusti
authors.forename: Michel
authors.initials: M
authors.lastname: Burnier
mesh_terms: D015415:Biomarkers; D001830:Body Surface Area; D003404:Creatinine / Q000378:metabolism; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000188:drug therapy / Q000503:physiopathology*; D007677:Kidney Function Tests / Q000592:standards*; D009765:Obesity / Q000503:physiopathology*; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D010599:Pharmacokinetics; D015203:Reproducibility of Results; D012107:Research Design
chemical_list: D015415:Biomarkers; D004364:Pharmaceutical Preparations; D003404:Creatinine