Angela R. Russell

The Accuracy of Hand-to-Hand Bioelectrical Impedance Analysis in Predicting Body Composition in College-Age Female Athletes

Esco, MR, Olson, MS, Williford, HN, Lizana, SN, and Russell, AR. The accuracy of hand-to-hand bioelectrical impedance analysis in predicting body composition in college-age female athletes. J Strength Cond Res 25(4): 1040-1045, 2011-The purpose of this investigation was to determine the accuracy of hand-to-hand bioelectrical impedance analysis (BIA) for estimating body composition in college-age female athletes using dual-energy X-ray absorptiometry (DEXA) as the criterion measure. Forty National Association for Intercollegiate Athletics college female athletes volunteered to participate in this study. For each participant, total body fat percentage (BF%) and fat-free mass (FFM) were obtained via BIA and DEXA. The mean BF% and FFM values obtained by BIA were compared with the criterion DEXA measure. The DEXA strongly correlated to the BIA for BF% (r = 0.74, R2 = 0.55, SEE = 3.60, and p < 0.01) and FFM (r = 0.84, R2 = 0.71, SEE = 2.45, p < 0.01). However, when compared with the DEXA, the mean values for BIA were significantly lower for BF% (DEXA = 27.6 ± 5.3%, BIA = 22.5 ± 3.5%, p < 0.01) and higher for FFM (DEXA = 47.2 ± 4.5 kg, BIA = 50.6 ± 4.6 kg, p < 0.01). The results of this investigation indicate that hand-to-hand BIA significantly underestimates BF% and overestimated FFM in college-age female athletes when compared with the criterion DEXA. Practitioners should use caution when analyzing body composition with hand-held BIA in a population of athletic women.

Validity of the body adiposity index in adults with Down syndrome

The purpose of this investigation was to determine the agreement between the body adiposity index (BAI) and dual energy X-ray absorptiometry (DXA) for measuring BF% in adults with Down syndrome (DS). Twenty adults (male: n=10; female: n=10) with Down syndrome volunteered to participate in this study. Criterion BF% was determined by DXA and predicted BF% was estimated by the BAI method. There was a significant mean difference (p<0.001) between DXA BF% (39.94±10.80%) and the BAI BF% (42.60±8.19%). The correlation between the two BF% variables was large and significant (r=0.73, p<0.001). However, the standard error of the estimate and total error was 7.79% and 7.86%, respectively. Additionally, the 95% limits of agreement ranged from 12.21% below to 17.52% above the constant error of 2.65%. Our findings suggest that on average, the BAI significantly overestimated BF% when compared to DXA values. Though there was a strong correlation between both methods, the wide limits of agreement suggest there is large amount of individual error when estimating BF% via the BAI. Therefore, the use of the BAI for individuals with DS does not appear to be accurate for estimating BF%.

Agreement of BMI-Based Equations and DXA in Determining Body-Fat Percentage in Adults With Down Syndrome.

The purpose of this investigation was to evaluate measurements of body-fat percentage (BF%) in 4 body-mass-index- (BMI) -based equations and dual-energy X-ray absorptiometry (DXA) in individuals with Down syndrome (DS). Ten male and 10 female adults with DS volunteered for this study. Four regression equations for estimating BF% based on BMI previously developed by Deurenberg et al. (DE(BMI-BF%)), Gallagher et al. (GA(BMI-BF%)), Womersley & Durnin (WO(BMI-BF%)), and Jackson et al. (JA(BMI-BF%)) were compared with DXA. There was no significant difference (p = .659) in mean BF% values between JA(BMI-BF%) (BF% = 40.80% ± 6.3%) and DXA (39.90% ± 11.1%), while DE(BMI-BF%) (34.40% ± 9.0%), WO(BMI-BF%) (35.10% ± 9.4%), and GA(BMI-BF%) (35.10% ± 9.4%) were significantly (p < .001) lower. The limits of agreement (1.96 SD of the constant error) varied from 9.80% to 16.20%. Therefore, BMI-based BF% equations should not be used in individuals with DS.

Relative accuracy of body adiposity index and relative fat mass in participants with and without down syndrome

Background/ObjectivesThe body adiposity index (BAI) and relative fat mass (RFM) are anthropometric measures developed to estimate body composition (%Fat). There is limited research validating these methods of body composition assessment in adults with Down syndrome (DS). The aim of this study was to examine the accuracy of the BAI and RFM in a sample of adults with- and without DS. We hypothesize that the RFM would provide greater accuracy than the BAI when estimating %Fat.Subjects/MethodsBAI and RFM were assessed in a sample of adults (n = 235, 50.2% female, 20.0% DS, 23.1 ± 6.7 years). %Fat assessed using dual-energy X-ray absorptiometry served as the criterion method of body composition. Between-group differences were assessed using a two-way (SEX × DS) analysis of variance.ResultsBAI overestimated %Fat in men without DS, but underestimated %Fat in women without DS (4.1 ± 4.5%Fat vs. −3.5 ± 4.6%Fat, respectively, p < 0.001). BAI overestimated %Fat in men and women with DS (4.7 ± 7.8%Fat vs. 0.8 ± 7.5%Fat, respectively, p = 0.090). RFM slightly overestimated %Fat in male and female participants without DS, and did not vary by sex (0.9 ± 4.0%Fat vs. 0.2 ± 4.2%Fat, respectively, p = 0.248). RFM underestimated %Fat in men and women with DS, with no differences observed between sexes (−2.1 ± 5.3%Fat vs. −2.2 ± 6.9%Fat, respectively, p = 0.953).ConclusionsThe BAI and RFM can be used to estimate body composition in individuals with- and without DS, however, the RFM yields greater accuracy and is recommended when more advanced methods of body composition assessment are unavailable or create unwanted participant burden.