Sarton-Miller Isabelle, Holman Darryl J, Spielvogel Hilde
Department of Anthropology, University of Washington, Seattle, Washington 98195, USA.
Am J Hum Biol. 2003 Jul-Aug;15(4):554-65. doi: 10.1002/ajhb.10162.
We developed a simple, non-invasive, and affordable method for estimating net energy expenditure (EE) in children performing activities at high altitude. A regression-based method predicts net oxygen consumption (VO(2)) from net heart rate (HR) along with several covariates. The method is atypical in that, the "net" measures are taken as the difference between exercise and resting VO(2) (DeltaVO(2)) and the difference between exercise and resting HR (DeltaHR); DeltaVO(2) partially corrects for resting metabolic rate and for posture, and DeltaHR controls for inter-individual variation in physiology and for posture. Twenty children between 8 and 13 years of age, born and raised in La Paz, Bolivia (altitude 3,600m), made up the reference sample. Anthropometric measures were taken, and VO(2) was assessed while the children performed graded exercise tests on a cycle ergometer. A repeated-measures prediction equation was developed, and maximum likelihood estimates of parameters were found from 75 observations on 20 children. The final model included the variables DeltaHR, DeltaHR(2), weight, and sex. The effectiveness of the method was established using leave-one-out cross-validation, yielding a prediction error rate of 0.126 for a mean DeltaVO(2) of 0.693 (SD 0.315). The correlation between the predicted and measured DeltaVO(2) was r = 0.917, suggesting that a useful prediction equation can be produced using paired VO(2) and HR measurements on a relatively small reference sample. The resulting prediction equation can be used for estimating EE from HR in free-living children performing habitual activities in the Bolivian Andes.
我们开发了一种简单、无创且经济实惠的方法，用于估算在高海拔地区进行活动的儿童的净能量消耗（EE）。一种基于回归的方法可根据净心率（HR）以及几个协变量预测净耗氧量（VO₂）。该方法的非典型之处在于，“净”测量值取运动时与静息时VO₂的差值（ΔVO₂）以及运动时与静息时HR的差值（ΔHR）；ΔVO₂部分校正了静息代谢率和姿势，而ΔHR则控制了个体生理差异和姿势。20名年龄在8至13岁之间、在玻利维亚拉巴斯（海拔3600米）出生并长大的儿童构成了参考样本。测量了人体测量学指标，并在儿童在自行车测力计上进行分级运动测试时评估了VO₂。开发了一个重复测量预测方程，并从对20名儿童的75次观察中得出了参数的最大似然估计值。最终模型包括变量ΔHR、ΔHR²、体重和性别。使用留一法交叉验证确定了该方法的有效性，对于平均ΔVO₂为0.693（标准差0.315），预测误差率为0.126。预测的和测量的ΔVO₂之间的相关性为r = 0.917，这表明使用相对较小的参考样本上的配对VO₂和HR测量值可以生成一个有用的预测方程。所得的预测方程可用于根据在玻利维亚安第斯山脉进行日常活动的自由生活儿童的心率估算EE。
