Comparison of DXA and water measurements of body fat following gastric bypass surgery and a physiological model of body water, fat, and muscle composition
- 1 September 2010
- journal article
- research article
- Published by American Physiological Society in Journal of Applied Physiology
- Vol. 109 (3), 786-795
- https://doi.org/10.1152/japplphysiol.00278.2010
Abstract
Measurement of body composition changes following bariatric surgery is complicated because of the difficulty of measuring body fat in highly obese individuals that have increased photon absorption and are too large for the standard dual-energy X-ray absorptiometry (DXA) table. We reproducibly measured body composition from half-body DXA scans and compared the values of total body fat estimated from total body water (TBW) and DXA measurements before and after Roux-en-Y gastric bypass surgery (RYGB). DXA, TBW (deuterium dilution), extracellular water (ECW; bromide dilution), and intracellular water (ICW) measurement (by subtraction) were made before surgery and at 2 wk, 6 wk, 6 mo, and 12 mo after surgery. Twenty individuals completed baseline and at least four follow-up visits. DXA appeared to underestimate the fat and bone mass in extreme obesity (before surgery), whereas at 6 and 12 mo after surgery, the DXA and TBW fat measurements were similar. The ECW-to-ICW ratio was increased in obese individuals and increased slightly more after surgery. We describe a new model that explains this abnormal water composition in terms of the normal physiological changes that occur in body composition in obesity and weight loss. This model is also used to predict the muscle mass loss following RYGB.Keywords
This publication has 48 references indexed in Scilit:
- Body Composition Measured by Dual‐energy X‐ray Absorptiometry Half‐body Scans in Obese AdultsObesity, 2009
- The Sucrose Space of Human Subcutaneous Adipose Tissue in ObesityActa Medica Scandinavica, 2009
- Multifrequency bioelectrical impedance analysis and bioimpedance spectroscopy for monitoring fluid and body cell mass changes after gastric bypass surgeryClinical Nutrition, 2008
- Effect of pronounced weight loss on visceral fat, liver steatosis and adiponectin isoformsEuropean Journal of Clinical Investigation, 2008
- Body Composition, Dietary Intake, and Energy Expenditure After Laparoscopic Roux-en-Y Gastric Bypass and Laparoscopic Vertical Banded GastroplastyAnnals of Surgery, 2006
- Resting energy expenditure and fuel metabolism following laparoscopic adjustable gastric banding in severely obese women: relationships with excess weight lostInternational Journal of Obesity, 2006
- Laparoscopic gastric banding and body composition in morbid obesityNutrition, Metabolism and Cardiovascular Diseases, 2005
- Three-compartment model: critical evaluation based on neutron activation analysisAmerican Journal of Physiology-Endocrinology and Metabolism, 2004
- Body composition changes following laparoscopic gastric banding for morbid obesityActa Diabetologica, 2003
- Body Composition and Surgical Treatment of ObesityAnnals of Surgery, 1992