Body composition : methods of measurement, normative values and clinical use

Laurence Genton Graf
2011
Stricto sensu, lean body mass is not synonymous of FFM as it contains both essential and non-essential lipids. However, in the literature, they are often used interchangeably. 2. Importance of body composition determination Determination of body composition is part of the nutritional assessment, as well as clinical history, medical examination, anthropometrics and biological markers (table 2). Table 2: Parameters allowing assessment of nutritional state (adapted from (3)) Parameters Clinical
more » ... ameters Clinical history Medical examination Weight, Height Biological markers Body composition Energy balance (needs vs. intakes and losses), weight history, appetite Abnormalities of skin, hair, nails, digestive symptoms, edema... Calculation of body mass index Plasma: total protein, albumin, transthyretin, transferrin, IGF-1, lymphocyte count Urine: creatine, 3-méthyl-histidine, Skinfold thickness, circumferences, bioelectrical impedance analysis, dual-energy x-ray absorptiometry... However, body composition is often not measured because of unavailability of measurement methods, and lack of experience and knowledge. consequently, nutritional assessment often relies only on anthropometry, laboratory values and evaluation of energy balance (4). Unfortunately, anthropometric parameters give only a crude estimation of body composition. In women, a high body mass index (BMI = weight (kg)/height (m) 2 )) has been associated with a high FFM and FM while in men it may reflect only high FM (5). In patients, as those with chronic hypercapnic failure, BMI may underestimate FFM depletion (6). Knowing that changes in FFM and FM carry health implications, assessment of body composition is preferable to anthropometrics for guidance of nutritional care. Bedside methods 1. Generalities The afore-mentioned reference methods are expensive, require extensive operator training and cannot be performed at the patient's bedside. Thus, in clinical routine, health care providers generally evaluate body composition through BMI, skinfold thickness, circumferences or bioelectrical impedance analysis. Skinfold thickness and circumferences Skinfold thickness predicts percent body fat from measurements of subcutaneous fatfolds. Among 50 frequently used equations for FM and FFM prediction, the most common areas for taking skinfold measurements are at the triceps, subscapular, abdominal and iliac crest, thigh, biceps, calf, chest, umbilicus and thorax, on the right side (56). Its main limitation is the interobserver variability, which can be due to the calipers used, the differences in location of the anatomical sites and the technique of grasping the skinfolds. The other limitations are the validation of equations, which were developed in one population but may not be valid in another population, and obesity (57).
doi:10.13097/archive-ouverte/unige:17006 fatcat:6j6bba4v5rguvgv4heh56u4tx4