Body surface area estimation and its impact on predicting appendicular skeletal muscle mass with a mechanistic model based on the Reference Man

Abstract.

The purpose of this study was to analyze the difference between the equations presented by Du Bois and Du Bois (1916) and Livingston and Lee (2001), used to estimate body surface area (BSA) and its impact on predicting appendicular skeletal muscle mass (ASMM) in adults, using a model based on the Reference Man (Fuller et al. 1992). Subjects were 666 Caucasian women (44.3±15.2 years, 63.7±10.5 kg, 1.57±0.07 m, 26.0±4.3 kg/m²) and 316 Caucasian men (42.8±15.4 years, 79.8±12.5 kg, 1.72±0.07 m, 26.8±3.8 kg/m²). Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. Du Bois’s and Livingston’s BSA equations were used to calculate ASMM according to Fuller’s method. As compared to the new Livingston equation, Du Bois’s equation underestimated (p<0.05) BSA in women (-0.08 m²) and in men (-0.06 m²). On the other hand, ASMM was overestimated in the arms, legs, and total body with Du Bois’s equation. This effect was of greater magnitude in obese subjects.