Evaluation of Skinfold Techniques in People with Down Syndrome: Development of a New Equation

The primary aim of this study was to evaluate the accuracy of skinfold thickness (SFT) measurements for the estimation of %Fat when compared to dual energy X-ray absorptiometry (DXA) in individuals with Down syndrome (DS). The secondary aim was to develop a new SFT-based body fat equation (SFT_NICKERSON). SFT-based %Fat was estimated using a body fat equation from González-Agüero (SFT_G-A) and body density conversion formulas from Siri (SFT_SIRI) and Brozek (SFT_BROZEK). Criterion %Fat was measured via DXA. SFT_G-A, SFT_SIRI, and SFT_BROZEK were significantly lower than DXA (mean differences ranged from -7.59 to -13.51%; all p < 0.001). The SEE values ranged from 3.47% (SFT_BROZEK) to 8.60% (SFT_G-A). The 95% limits of agreement were greater than ±10% for all comparisons. Mid-axilla and suprailium were significant predictors of %Fat (both p < 0.05). %Fat SFT_NICKERSON = 10.323 + (0.661 × mid-axilla) + (0.712 × suprailium). Age and all other skinfold sites were not statically significant in the regression model (all p > 0.05). Current findings indicate that SFT_G-A, SFT_SIRI, and SFT_BROZEK erroneously place an individual with excessive adiposity in a normal healthy range. Accordingly, the current study developed a new equation (SFT_NICKERSON) that can easily be administered in people with DS in a quick and efficient time frame. However, further research is warranted in this area.