A radiographic method of quantifying protein-calorie undernutrition

Abstract

Estimation of midarm adipose tissue and muscle by the anthropometric technique is based on the idealized assumption that the arm and its muscle compartments are circular, and that fat is distributed evenly around the arm. We examined the validity of these assumptions by computerized axial tomography of the midarm in 21 subjects ranging from 65 to 255% of ideal body weight. Computerized axial tomography identified three errors inherent in the anthropometric method: 1) The arm and its muscle compartment were rarely circular, but resembled instead an ellipse and “cloverleaf”, respectively; 2) fat was distributed asymmetrically around the arm, and furthermore when triceps skinfold was 150% ideal body weight, however, anthropometric estimates of MAMA and midarm fat area differed from the radiographic values by >50% even after the above two types of correction. Midarm computerized axial tomography scan provides an accurate alternative to the anthropometric method for estimating midarm muscle and fat in these obese individuals.