Prediction of DXA-determined whole body fat from skinfolds: importance of including skinfolds from the thigh and calf in young, healthy men and women

Abstract

Objective: To investigate the relationship of percent body fat (%fat), assessed by dual energy-X-ray absorptiometry (DXA) or a four-compartment model, with upper body and lower limb skinfolds. Design: Cross-sectional design involving forward stepwise and hierarchical multiple regression analyses to assess the relationship of %fat with skinfolds and a combination of four commonly used upper body skinfolds (biceps, triceps, subscapular and iliac crest) with the calf and thigh skinfolds. Setting: University research laboratory. Subjects: In all, 31 females, mean age 20.9 (72.0) y, and 21 males, mean age 22.3 (75.5) y volunteered for this study, which was approved by the Ethics Committee of the School of Sport, Health and Exercise Sciences, University of Wales, Bangor. Measurements: %fat from DXA in both groups, and %fat from a four-compartment (water, bone mineral mass, fat and residual) model (%fat4C) in females only. Skinfolds were measured at the abdomen, iliac crest, biceps, triceps, subscapular, calf and thigh. Results: All skinfolds were positively associated with DXA estimates of %fat (Po0.01). In males and females, the thigh skinfold had the highest correlation with %fat. This was also observed when %fat4C was used as the criterion in females. Stepwise multiple regression analysis using %fatDXA as the criterion selected the thigh (R 2 ¼ 0.82), calf (R 2 change 0.04) and iliac crest (R 2 change ¼ 0.03) for females, and the thigh (R 2 ¼ 0.79), iliac crest (R 2 change ¼ 0.11) and abdomen (R 2 change ¼ 0.03) for males (all Po0.01). When %fat4C was used as the criterion in the females, only the thigh was selected as a significant predictor (R 2 ¼ 0.76). Independent prediction factors were created from the sum of biceps, triceps, subscapular and iliac crest ( P 4skf) and from the sum of the thigh and calf ( P thigh þ calf). These factors were then entered into a hierarchical multiple linear regression analysis to predict percent fat. Order of entry was varied to allow the assessment of unique variance accounted for by each predictor. The sum of the thigh and calf explained more variance in %fatDXA than that explained by the P 4skf alone, irrespective of the order of entry in both males and females. This was also observed when %fat4C was used as the criterion in the females. Conclusions:The results of this study confirm that lower body skinfolds are highly related to percent body fat in fit and healthy young men and women, and uphold current recommendations by the British Olympic Association to include the thigh skinfold with P 4skf. Conventional use of the P 4skf to estimate percent body fat is significantly enhanced by the inclusion of the thigh and calf skinfolds, either independently or in combination. In this group of males and females, the sum of the thigh and calf skinfolds accounted for the most variance in percent fat.

Critical Appraisal of Data Acquisition in Body Composition: Evaluation of Methods, Techniques and Technologies on the Anatomical Tissue-System Level

“…On the other hand, we find an important www.intechopen.com Data Acquisition 296 number of validation and application studies that support the DXA technique as convenient, as the criterion for %fat, for lean body mass (LBM), and as a criterion for bone mineral content (BMC) (Clasey et al, 1999;Haarbo et al, 1991;Johansson et al, 1993;Prior et al, 1997;Pritchard et al, 1993). A number of authors as mentioned in Provyn et al (2008) suggest DXA as the gold standard for validation of other techniques essential for the measurement of BC (Eston et al, 2005;Poortmans et al, 2005;Salamone et al, 2000). In addition to the violation of basic assumptions as referred to earlier, one needs to repeat and underline that DXA, hydrodensitometry, anthropometry, air-, gas-and water displacement methods, bioelectrical impedance (BIA) are all indirect in vivo techniques for measuring BC.…”

“…This model is based on the assumption of a density constancy of 0.901 g/ml for fat and of 1.100 g/ml for FFM and, irrespective the technique or method it was used for, the background of constancy was projected to all tissues that compose FFM and irrespective the measurement of fat (Behnke et al, 1942;Siri, 1956). A l t h o u g h t h i s k n o w l e d g e , i n p a r t o r a s a whole, has been extensively described and discussed in the literature, one must ascertain that HD has not been abandoned as a reference and is used in various sport medical centers and sport science laboratories still (Brodie et al, 1998;Eston et al, 2005;Westerterp et al, 2008;. Readers are reminded that distinction needs to be made between HD for the purpose of %fat determination and for the purpose of single tissue density measurement.…”

“…In HD, but also in newer technologies, e.g. DXA body fat is calculated on the constancy assumption that ≈73% of LBM is water (Brommage, 2003;Clasey et al, 1999;Eston et al, 2005;Prior et al, 1997). This assumed constancy of hydration e.g.…”

Suprailiac or Abdominal Skinfold Thickness Measured with a Skinfold Caliper as a Predictor of Body Density in Japanese Adults

“…Measurement of subcutaneous fat thickness with skinfold calipers is a simple and inexpensive technique for body composition assessment that has been used in the field setting (Eston et al 1994(Eston et al , 2005Demura et al 1999;Garcia et al 2005). In Japan, Nagamine and Suzuki's formula (1964) has been most widely used as an equation for predicting body density.…”

Regression Equation from Dual Energy X Ray Absorptiometry (DEXA) for Estimating Muscle Mass Segment

“…Fat-free mass given by the DEXA method permits estimating the body mass and the bone mineral content (Williams et al, 2006;Eisenmann et al, 2004;Flegal et al, 2009) with a low variation coefficient (between 1% and 4%) in the different components of the individuals and a minimal X-ray exposure, thus making it a non-invasive technique (van der Ploeg et al, 2003;Eston et al, 2005), consequently becoming the reference method par excellence (Visser et al, 2003) and one of the most accurate for the estimation of muscle mass (Freda et al, 2009), which is even borne out by the European Society for Clinical Nutrition and Metabolism as a reference method for the evaluation of body composition.…”