Heber D, Ingles S, Ashley J M, Maxwell M H, Lyons R F, Elashoff R M
Department of Medicine, UCLA School of Medicine 90024-1742.
Am J Clin Nutr. 1996 Sep;64(3 Suppl):472S-477S. doi: 10.1093/ajcn/64.3.472S.
To assess whether bioelectrical impedance analysis (BIA) provides clinically useful information on body composition beyond that obtained from measuring height and weight, we clinically classified 306 obese patients (233 females and 73 males) into tertiles of increasing fat-free mass estimated by BIA. Because fat-free mass by BIA is an estimate of lean body mass, the lowest tertile was clinically defined as sarcopenic obesity (reduced lean body mass), as contrasted with proportionate or muscular obesity in the next two tertiles. Fat mass in patients in each of the above tertiles based on BIA was then compared with fat mass estimated by using the equations of Garrow and Webster with body mass index (weight/height2). BIA-estimated fat mass was 4.3 kg greater in the sarcopenic group (n = 102) than predicted from body mass index. Fat mass predicted by BIA in the proportionate (n = 102) and muscular (n = 102) groups differed by less than the SEE of fat mass predicted by BMI. In premenopausal women at increased risk of breast cancer BIA showed a high prevalence of sarcopenic obesity (28/30) in these women at normal body mass indexes. Thus, BIA may be clinically useful for demonstrating sarcopenic obesity, but additional studies are needed to determine the metabolic and clinical significance of sarcopenic obesity.
为了评估生物电阻抗分析（BIA）能否提供超出身高和体重测量所得的有关身体成分的临床有用信息，我们将306例肥胖患者（233例女性和73例男性）根据BIA估计的无脂肪量增加情况临床分类为三个三分位数组。由于BIA得出的无脂肪量是瘦体重的一个估计值，最低的三分位数组在临床上被定义为肌肉减少性肥胖（瘦体重降低），与后两个三分位数组中的比例性肥胖或肌肉性肥胖形成对比。然后将上述基于BIA的每个三分位数组患者的脂肪量与使用加罗（Garrow）和韦伯斯特（Webster）公式结合体重指数（体重/身高²）估计的脂肪量进行比较。在肌肉减少性肥胖组（n = 102）中，BIA估计的脂肪量比根据体重指数预测的脂肪量高4.3千克。在比例性肥胖组（n = 102）和肌肉性肥胖组（n = 102）中，BIA预测的脂肪量差异小于BMI预测的脂肪量的标准误。在患乳腺癌风险增加的绝经前女性中，BIA显示这些体重指数正常的女性中肌肉减少性肥胖的患病率很高（28/30）。因此，BIA在临床上可能有助于诊断肌肉减少性肥胖，但需要进一步研究以确定肌肉减少性肥胖的代谢和临床意义。
