Stewart S P, Bramley P N, Heighton R, Green J H, Horsman A, Losowsky M S, Smith M A
Department of Clinical Medicine, University of Leeds, General Infirmary.
Br J Nutr. 1993 May;69(3):645-55. doi: 10.1079/bjn19930066.
In twenty-eight healthy subjects, ten men and eighteen women, with a range in body mass index (BMI) of 17.9-31.6 kg/m2 and an age range 20-60 years, body composition was estimated by dual-energy X-ray absorptiometry (DEXA), skinfold anthropometry (SFA) and bioelectrical impedance analysis (BIA) of the 'whole body' and body segments. In thirteen subjects muscle mass was also estimated by 24 h urinary creatinine excretion. The relationship between fat-free mass (FFM) determined by DEXA and the impedance index of each body segment (calculated as length2/impedance (Z)) was analysed. The strongest correlation was between FFM (DEXA) and height2/'whole-body' Z (ZW) (r 0.97 for the combined sexes, standard error of estimate (SEE) 2.72 kg). Separate prediction equations were found to be necessary for males and females when estimating FFM from BIA measurement of the arm (for men, r 0.93, SEE 1.98 kg; for women, r 0.75, SEE 2.87 kg). Muscle mass derived from 24 h creatinine excretion showed weak correlation with FFM (DEXA) (r 0.57, P = 0.03) and no correlation with FFM (SFA). FFM (SFA) correlated well with both FFM (DEXA) (r 0.96, SEE = 3.12 kg) and with height2/ZW (r 0.92, SEE 4.52 kg). Measurement of the impedance of the arm offers a simple method of assessing the composition of the whole body in normal individuals, and it appears comparable with other methods of assessment.
在28名健康受试者中，包括10名男性和18名女性，体重指数（BMI）范围为17.9 - 31.6 kg/m²，年龄范围为20 - 60岁，通过双能X线吸收法（DEXA）、皮褶厚度人体测量法（SFA）以及对“全身”和身体各部位的生物电阻抗分析（BIA）来估计身体成分。在13名受试者中，还通过24小时尿肌酐排泄量来估计肌肉量。分析了由DEXA测定的去脂体重（FFM）与每个身体部位的阻抗指数（计算为长度²/阻抗（Z））之间的关系。最强的相关性存在于FFM（DEXA）与身高²/“全身”Z（ZW）之间（男女合并数据时r为0.97，估计标准误（SEE）为2.72 kg）。当从手臂的BIA测量值估计FFM时，发现男性和女性需要分别使用预测方程（对于男性，r为0.93，SEE为1.98 kg；对于女性，r为0.75，SEE为2.87 kg）。由24小时肌酐排泄量得出的肌肉量与FFM（DEXA）的相关性较弱（r为0.57，P = 0.03），与FFM（SFA）无相关性。FFM（SFA）与FFM（DEXA）（r为0.96，SEE = 3.12 kg）以及身高²/ZW（r为0.92，SEE为4.52 kg）均具有良好的相关性。测量手臂的阻抗为评估正常个体的全身成分提供了一种简单方法，并且它似乎与其他评估方法相当。
