Lee Vinson R, Blew Rob M, Farr Josh N, Tomas Rita, Lohman Timothy G, Going Scott B
University of Arizona, College of Medicine, Department of Physiology, Tucson, AZ.
University of Arizona, College of Agriculture and Life Sciences, Department of Nutritional Sciences, Tucson, AZ.
Int J Body Compos Res. 2013;11(1):1-8.
Assess the utility of peripheral quantitative computed tomography (pQCT) for estimating whole body fat in adolescent girls.
Our sample included 458 girls (aged 10.7 ± 1.1y, mean BMI = 18.5 ± 3.3 kg/m) who had DXA scans for whole body percent fat (DXA %Fat). Soft tissue analysis of pQCT scans provided thigh and calf subcutaneous percent fat and thigh and calf muscle density (muscle fat content surrogates). Anthropometric variables included weight, height and BMI. Indices of maturity included age and maturity offset. The total sample was split into validation (VS; n = 304) and cross-validation (CS; n = 154) samples. Linear regression was used to develop prediction equations for estimating DXA %Fat from anthropometric variables and pQCT-derived soft tissue components in VS and the best prediction equation was applied to CS.
Thigh and calf SFA %Fat were positively correlated with DXA %Fat (r = 0.84 to 0.85; <0.001) and thigh and calf muscle densities were inversely related to DXA %Fat (r = -0.30 to -0.44; < 0.001). The best equation for estimating %Fat included thigh and calf SFA %Fat and thigh and calf muscle density (adj. R = 0.90; SEE = 2.7%). Bland-Altman analysis in CS showed accurate estimates of percent fat (adj. R = 0.89; SEE = 2.7%) with no bias.
Peripheral QCT derived indices of adiposity can be used to accurately estimate whole body percent fat in adolescent girls.
评估外周定量计算机断层扫描（pQCT）在估计青春期女孩全身脂肪方面的效用。
我们的样本包括458名女孩（年龄10.7±1.1岁，平均BMI = 18.5±3.3 kg/m²），她们接受了双能X线吸收法（DXA）扫描以测量全身脂肪百分比（DXA %脂肪）。pQCT扫描的软组织分析提供了大腿和小腿皮下脂肪百分比以及大腿和小腿肌肉密度（肌肉脂肪含量替代指标）。人体测量变量包括体重、身高和BMI。成熟度指标包括年龄和成熟度偏移。总样本分为验证组（VS；n = 304）和交叉验证组（CS；n = 154）。在验证组中，使用线性回归从人体测量变量和pQCT衍生的软组织成分中建立预测方程以估计DXA %脂肪，并将最佳预测方程应用于交叉验证组。
大腿和小腿皮下脂肪百分比与DXA %脂肪呈正相关（r = 0.84至0.85；P < 0.001），大腿和小腿肌肉密度与DXA %脂肪呈负相关（r = -0.30至-0.44；P < 0.001）。估计%脂肪的最佳方程包括大腿和小腿皮下脂肪百分比以及大腿和小腿肌肉密度（调整后R² = 0.90；标准误 = 2.7%）。交叉验证组的Bland-Altman分析显示脂肪百分比估计准确（调整后R² = 0.89；标准误 = 2.7%），无偏差。
外周定量CT得出的肥胖指数可用于准确估计青春期女孩的全身脂肪百分比。
