Roubenoff R
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
Am J Clin Nutr. 1996 Sep;64(3 Suppl):459S-462S. doi: 10.1093/ajcn/64.3.459S.
Bioelectrical impedance analysis (BIA) is a promising tool in the evaluation of body composition in large population studies because it is fast, is inexpensive, and does not require extensive operator training or cross-validation. The empiric nature of the relation between resistance and reactance measured by BIA and body composition has led to the development of equations that translate the raw data into liters of body water or kilograms of fat-free mass (FFM) or fat mass. These equations may not be easily transferred from one population to another if the populations differ significantly in important determinants of body composition such as age, obesity, and illness. I review two recent studies from the Framingham Heart Study in which BIA was first compared with dual-energy X-ray absorptiometry (DXA) as a validation technique, and then compared with the body mass index (BMI, in kg/m2) as an alternative estimate of body fat. BIA was a good predictor of DXA-derived FFM (r = 0.85-0.88, P < 0.001) and was superior to BMI as an estimator of body fat.
生物电阻抗分析（BIA）在大规模人群研究的身体成分评估中是一种很有前景的工具，因为它速度快、成本低，且不需要操作人员进行大量培训或交叉验证。通过BIA测量的电阻和电抗与身体成分之间关系的经验性质，促使了一些方程的开发，这些方程可将原始数据转化为身体水分升数或无脂肪体重（FFM）或脂肪量的千克数。如果不同人群在身体成分的重要决定因素（如年龄、肥胖和疾病）方面存在显著差异，这些方程可能不易从一个人群转移到另一个人群。我回顾了弗明汉心脏研究的两项最新研究，其中首先将BIA与双能X线吸收法（DXA）作为一种验证技术进行比较，然后将其与体重指数（BMI，单位为kg/m²）作为身体脂肪的替代估计值进行比较。BIA是DXA得出的FFM的良好预测指标（r = 0.85 - 0.88，P < 0.001），并且作为身体脂肪的估计指标优于BMI。
