Submitted on March 5, 2007
Accepted on August 23, 2007
Applicability of a segmental bioelectrical impedance analysis for predicting the whole body skeletal muscle volume
Noriko I Tanaka1*, Masae Miyatani2, Yoshihisa Masuo3, Tetsuo Fukunaga3, and Hiroaki Kanehisa4
1 Department of Sport System, Kokushikan University, Tama, Tokyo, Japan
2 Rehabilitation Engineering Lab, Lyndhurst Centre Toronto Rehabilitation Institute, Sutherland Drive Toronto, Canada
3 Department of Sport Sciences, School of Human Sciences, Tokorozawa, Saitama, Japan
4 Department of Life Sciences (Sports Sciences), University of Tokyo, Meguro, Tokyo, Japan
* To whom correspondence should be addressed. E-mail: ishiguro{at}kokushikan.ac.jp.
This study aimed to test the hypothesis that a segmental bioelectrical impedance (BI) analysis can predict whole body skeletal muscle (SM) volume more accurately than a whole-body BI analysis. Thirty males (19~34 yrs) participated in this study. They were divided into validation (n=20) and cross-validation groups (n=10). The BI values were obtained using two methods; whole-body BI analysis which determines impedance between the wrist and ankle, and segmental BI analysis which determines the impedance of every body segment in both sides of the upper arm, lower arm, upper leg and lower leg, and five parts of the trunk. Using a magnetic resonance imaging method, whole body SM volume was determined as a reference (SMVMRI). Simple and multiple regression analyses were applied to (length)2/Z (BI index) values for the whole-body and every body segment, respectively, to develop the prediction equations of SMVMRI. In the validation group, there were no significant differences between the measured and estimated SMV and no systematic errors in either BI analysis. In the cross-validation group, the whole-body BI analysis produced systematic errors and resulted in the overestimation of SMVMRI, but the segmental BI analysis was cross-validated. In the pooled data, the segmental BI analysis produced a prediction equation, which involves the BI indices of the trunk and upper thigh as independent variables, with a SE of estimation of 1693.8 cm3 (6.1%). Thus, the findings obtained here indicated that the segmental BI analysis is superior to the whole-body BI analysis for estimating SMVMRI.
