title: Cross-mode bioelectrical impedance analysis in a standing position for estimating fat-free mass validated against dual-energy x-ray absorptiometry.
abstract: Bioelectrical impedance analysis (BIA) is commonly used to assess body composition. Cross-mode (left hand to right foot, Z(CR)) BIA presumably uses the longest current path in the human body, which may generate better results when estimating fat-free mass (FFM). We compared the cross-mode with the hand-to-foot mode (right hand to right foot, Z(HF)) using dual-energy x-ray absorptiometry (DXA) as the reference. We hypothesized that when comparing anthropometric parameters using stepwise regression analysis, the impedance value from the cross-mode analysis would have better prediction accuracy than that from the hand-to-foot mode analysis. We studied 264 men and 232 women (mean ages, 32.19 ± 14.95 and 34.51 ± 14.96 years, respectively; mean body mass indexes, 24.54 ± 3.74 and 23.44 ± 4.61 kg/m2, respectively). The DXA-measured FFMs in men and women were 58.85 ± 8.15 and 40.48 ± 5.64 kg, respectively. Multiple stepwise linear regression analyses were performed to construct sex-specific FFM equations. The correlations of FFM measured by DXA vs. FFM from hand-to-foot mode and estimated FFM by cross-mode were 0.85 and 0.86 in women, with standard errors of estimate of 2.96 and 2.92 kg, respectively. In men, they were 0.91 and 0.91, with standard errors of the estimates of 3.34 and 3.48 kg, respectively. Bland-Altman plots showed limits of agreement of -6.78 to 6.78 kg for FFM from hand-to-foot mode and -7.06 to 7.06 kg for estimated FFM by cross-mode for men, and -5.91 to 5.91 and -5.84 to 5.84 kg, respectively, for women. Paired t tests showed no significant differences between the 2 modes (P > .05). Hence, cross-mode BIA appears to represent a reasonable and practical application for assessing FFM in Chinese populations.
authors.affiliation: Department of Leisure, Recreation, and Tourism Management, Tzu-Hui Institute of Technology, Pingtung, Taiwan.
authors.forename: Ai-Chun
authors.initials: AC
authors.lastname: Huang
authors.affiliation: Department of Physical Education, National Taiwan University of Sport, Taichung, Taiwan.
authors.forename: Yu-Yawn
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Department of Radiology, Jen-Ai Hospital, Taichung, Taiwan.
authors.forename: Chih-Lin
authors.initials: CL
authors.lastname: Chuang
authors.affiliation: College of Health Science, Movement Activities and Lifetime Fitness, East Stroudsburg University of Pennsylvania, East Stroudsburg, PA, USA.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Chiang
authors.affiliation: Sport Science Research Center, National Taiwan University of Sport, Taichung, Taiwan.
authors.forename: Hsueh-Kuan
authors.initials: HK
authors.lastname: Lu
authors.affiliation: Division of Gastroenterology and Hepatology, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Hung-Chi
authors.initials: HC
authors.lastname: Lin
authors.affiliation: Department of Applied Mathematics, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Kuen-Tsann
authors.initials: KT
authors.lastname: Chen
authors.affiliation: Department of Radiology, Jen-Ai Hospital, Taichung, Taiwan.
authors.forename: An-Chi
authors.initials: AC
authors.lastname: Hsiao
authors.affiliation: Office of Physical Education and Sport, National Chung Hsing University, Taichung, Taiwan; Research Center, Charder Electronic Co, Ltd, Taichung, Taiwan. Electronic address: abaqus0927@yahoo.com.tw.
authors.forename: Kuen-Chang
authors.initials: KC
authors.lastname: Hsieh
mesh_terms: D015502:Absorptiometry, Photon / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001823:Body Composition; D015992:Body Mass Index; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Bioelectrical impedance analysis; Body composition; Dual-energy x-ray absorptiometry; Electric impedance; Fat-free mass; Obesity