Use of Body Surface Area for Assessing Extracellular Fluid Volume and Glomerular Filtration Rate in Obesity
| Autor: | A. Michael Peters, Daphne M. Glass |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Adult
medicine.medical_specialty Body Surface Area Population Renal function urologic and male genital diseases Body Mass Index Internal medicine Extracellular fluid medicine Humans Obesity education Aged Retrospective Studies Body surface area education.field_of_study urogenital system business.industry Middle Aged Water-Electrolyte Balance medicine.disease female genital diseases and pregnancy complications Body Fluids Endocrinology Nephrology Kidney Diseases Extracellular Space business Body mass index Glomerular Filtration Rate Clearance |
| Zdroj: | American Journal of Nephrology. 31:209-213 |
| ISSN: | 1421-9670 0250-8095 |
| DOI: | 10.1159/000271272 |
| Popis: | Objective: To examine body surface area (BSA) for scaling extracellular fluid volume (ECV) in obesity. ECV varies less than glomerular filtration rate (GFR) in a clinical population and was therefore used as a surrogate for GFR on the grounds that if BSA is unsuitable for scaling GFR, it will also be unsuitable for ECV. Methods: GFR was measured in 917 patients using 51Cr-EDTA. GFR scaled to ECV was measured exclusively from the slope rate constant. ECV was calculated as GFR divided by GFR/ECV. Results: BSA correlated strongly with body mass index (BMI). ECV correlated strongly with BSA but the intercept was significantly lower than zero, indicating a disproportionate relation. ECV/BSA correlated with BSA but not with BMI. ECV in obese subjects was significantly less than in non-obese subjects individually matched for BSA. ECV/BSA was similar between obese and lean subjects matched for GFR/ECV and height. Conclusions: For subjects of similar BSA, a high BMI decreases ECV (the ‘obesity effect’). Subjects with high BMI generally have high BSA, which tends to increase ECV/BSA because of the disproportionate relation between ECV and BSA (the ‘BSA effect’). These opposing effects serendipitously and erroneously create the impression that BSA is suitable for scaling ECV (and by implication, GFR) in obesity. |
| Databáze: | OpenAIRE |
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