Body surface area prediction in normal-weight and obese patients

• Published in: American journal of physiology: endocrinology and metabolism 2001-09, Vol.281 (3), p.E586-E591
• Main Authors: Livingston, Edward H, Lee, Scott
• Format: Article
• Language: English
• Subjects: Body Height; Body Mass Index; Body Surface Area; Body Weight; Female; Humans; Male; Mathematics; Obesity - physiopathology; Regression Analysis
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.2001.281.3.e586

Veterans Affairs Medical Center, Greater Los Angeles Health Care System, and the University of California Los Angeles Center for Human Nutrition, Los Angeles, California 90073 None of the equations frequently used to predict body surface area (BSA) has been validated for obese patients. We applied the principles of body size scaling to derive an improved equation predicting BSA solely from a patient's weight. Forty-five patients weighing from 51.3 to 248.6 kg had their height and weight measured on a calibrated scale and their BSA calculated by a geometric method. Data were combined with a large series of published BSA estimates. BSA prediction with the commonly used Du Bois equation underestimated BSA in obese patients by as much as 20%. The equation we derived to relate BSA to body weight was a power function: BSA (m 2 ) = 0.1173 × Wt (kg) 0.6466 . Below 10 kg, this equation deviated significantly from the BSA vs. body weight curve, necessitating a different set of coefficients: BSA (m 2 ) = 0.1037 × Wt (kg) 0.6724 . Covariance of height and weight for patients weighing