Abstract:
Laboratory-based body-composition techniques include hydrostatic weighing (HW), dual-energy X-ray absorptiometry (DXA), measurement of total body water (TBW) by isotope dilution, measurement of total body potassium, and multicompartment models. Although these reference methods are used routinely, each has inherent practical limitations. Whole-body air-displacement plethysmography is a new practical alternative to these more traditional body-composition methods. We reviewed the principal findings from studies published between December 1995 and August 2001 that compared the BOD POD method (Life Measurement, Inc, Concord, CA) with reference methods and summarized factors contributing to the different study findings. The average of the study means indicates that the BOD POD and HW agree within 1% body fat (BF) for adults and children, whereas the BOD POD and DXA agree within 1% BF for adults and 2% BF for children. Few studies have compared the BOD POD with multicompartment models; those that have suggest a similar average underestimation of approximate 2-3% BF by both the BOD POD and HW. Individual variations between 2-compartment models compared with DXA and 4 -compartment models are partly attributable to deviations from the assumed chemical composition of the body. Wide variations among study means, -4.0% to 1.9% BF for BOD POD - HW and -3.0% to 1.7% BF for BOD POD - DXA, are likely due in part to differences in laboratory equipment, study design, and subject characteristics and in some cases to failure to follow the manufacturer\'s recommended protocol. Wide intersubject variations between methods are partly attributed to technical precision and biological error but to a large extent remain unexplained. On the basis of this review, future research goals are suggested.
摘要:
基于实验室的身体成分技术包括静压称重(HW),双能X射线吸收法(DXA),用同位素稀释法测量全身水(TBW),人体总钾的测量,和多隔间模型。尽管这些参考方法是常规使用的,每个都有固有的实际局限性。全身空气置换体积描记术是这些更传统的身体成分方法的一种新的实用替代方法。我们回顾了1995年12月至2001年8月发表的研究的主要发现,这些研究比较了BODPOD方法(寿命测量,Inc,康科德,CA)提供参考方法,并总结了导致不同研究结果的因素。研究平均值表明,成人和儿童的BODPOD和HW在1%的体脂(BF)范围内一致,而BODPOD和DXA在成人1%BF和儿童2%BF内一致。很少有研究将BODPOD与多隔室模型进行比较;那些建议BODPOD和HW平均低估约2-3%BF的人。与DXA和4室模型相比,2室模型之间的个体差异部分归因于与假定的身体化学成分的偏差。研究手段之间的差异很大,BODPOD-HW的-4.0%至1.9%BF,BODPOD-DXA的-3.0%至1.7%BF,部分可能是由于实验室设备的差异,研究设计,和主题特征,并且在某些情况下未能遵循制造商的推荐协议。方法之间的主体之间的广泛差异部分归因于技术精度和生物学误差,但在很大程度上仍无法解释。在此回顾的基础上,提出了未来的研究目标。