Comparison of multifrequency bioelectrical impedance analysis with dual-energy X-ray absorptiometry for assessment of percentage body fat in a large, healthy population
التفاصيل البيبلوغرافية
العنوان:
Comparison of multifrequency bioelectrical impedance analysis with dual-energy X-ray absorptiometry for assessment of percentage body fat in a large, healthy population
Background: Bioelectrical impedance analysis (BIA) is widely usedinclinicsandresearchtomeasurebodycomposition.However, the results of BIA validation with reference methods are contradictory, and few data are available on the influence of adiposity on the measurement of body composition by BIA. Objective:The goal was to determine the effects of sex and adiposityonthedifferenceinpercentagebodyfat(%BF)predictedbyBIA compared with dual-energy X-ray absorptiometry (DXA). Design:Atotalof591healthysubjectswererecruitedinNewfoundland and Labrador. %BF was predicted by using BIA and was comparedwiththatmeasuredbyDXA.Methodsagreementwasassessed by Pearson’s correlation and Bland and Altman analysis. Differences in %BF among groups based on sex and adiposity were analyzed by using one-factor analysis of variance with Bonferroni correction. Results: Correlations between BIA and DXA were 0.88 for the whole population, 0.78 for men, and 0.85 for women. The mean %BF determined by BIA (32.89 8.00%) was significantly lower than that measured by DXA (34.72 8.66%). The cutoffs were sex specific. BIA overestimated %BF by 3.03% and 4.40% when %BF was 15% in men and 25% in women, respectively, and underestimated %BF by 4.32% and 2.71% when %BF was 25% in men and 33% in women, respectively. Conclusions: BIA is a good alternative for estimating %BF when subjects are within a normal body fat range. BIA tends to overestimate %BF in lean subjects and underestimate %BF in obese subjects. Am J Clin Nutr 2005;81:74–8.