Norgan N G, Ferro-Luzzi A
Ann Hum Biol. 1985 Jan-Feb;12(1):1-15. doi: 10.1080/03014468500007521.
Regression equations for estimating body density and fatness from anthropometric measurements are usually specific to the populations from which they are derived, owing to methodological and biological factors. Some equations are, however, regarded as having general validity for subjects of different ages, levels of fatness and fitness. In this study, five such general equations were tested by comparing estimated body density (Dest) with measured body density (Dmeas) in 138 European men employed in an Italian shipyard. Body density was measured by underwater weighing with the simultaneous determination of lung residual volume. Measurements were also made of height, weight, eight skinfolds, four circumferences and seven diameters by standard techniques. Dest from the five general equations were significantly different from Dmeas (P less than 0.001). New prediction equations for estimating D were drawn up by simple and multiple regression of various combinations of skinfolds expressed as individual skinfolds, sums, log sums and the quadratic form. Equations were drawn up on a validation sample (N = 92) and tested on a cross-validation sample (N = 46). The form of skinfolds and the combination selected made little difference to the SEEs and R2 but the inclusion of age resulted in lower SEEs. Stepwise multiple regression produced an equation incorporating thorax and triceps skinfolds and age with an SEE of 6 kg/m3 and R2 of 79%. The derived equations were successfully cross-validated, Dmeas and Dest were not significantly different, ryy' and SEE were similar to those of the validation sample. When the cross-validation sample was divided into two according to age, density or VO2 max, the derived equations were applicable to the upper and lower groups for age or physical fitness but not to the groups differing in fatness. These equations should be validated further on other samples by studies performed with due regard to the methodological factors, both technical and statistical, that may result in specificity. However, the poor performance of the general equations tested and the specificity for fatness of the derived equations suggest that biological factors may preclude the development of general prediction equations for body density.
由于方法学和生物学因素，通过人体测量学指标估算身体密度和肥胖程度的回归方程通常特定于其推导所基于的人群。然而，有些方程被认为对不同年龄、肥胖程度和健康水平的受试者具有普遍有效性。在本研究中，通过比较138名受雇于意大利造船厂的欧洲男性的估计身体密度（Dest）和测量身体密度（Dmeas），对五个这样的通用方程进行了测试。身体密度通过水下称重并同时测定肺残气量来测量。还采用标准技术测量了身高、体重、八个皮褶厚度、四个周长和七个直径。五个通用方程得出的Dest与Dmeas有显著差异（P小于0.001）。通过将皮褶厚度的各种组合（表示为单个皮褶厚度、总和、对数总和和二次形式）进行简单和多元回归，得出了用于估算D的新预测方程。方程是在一个验证样本（N = 92）上制定的，并在一个交叉验证样本（N = 46）上进行了测试。皮褶厚度的形式和所选组合对标准误（SEE）和决定系数（R2）影响不大，但纳入年龄会使SEE降低。逐步多元回归得出一个包含胸部和三头肌皮褶厚度以及年龄的方程，其SEE为6 kg/m3，R2为79%。所推导的方程成功进行了交叉验证，Dmeas和Dest无显著差异，ryy'和SEE与验证样本相似。当根据年龄、密度或最大摄氧量（VO2 max）将交叉验证样本分为两组时，所推导的方程适用于年龄或身体素质较高和较低的组，但不适用于肥胖程度不同的组。这些方程应通过充分考虑可能导致特异性的技术和统计方法学因素的研究，在其他样本上进一步验证。然而，所测试的通用方程表现不佳以及所推导方程对肥胖程度的特异性表明，生物学因素可能阻碍身体密度通用预测方程的开发。
