Pietrobelli A, Faith M S, Allison D B, Gallagher D, Chiumello G, Heymsfield S B
Obesity Research Center, St. Luke's/Roosevelt Hospital, Columbia University, College of Physicians and Surgeons, New York, New York 10025, USA.
J Pediatr. 1998 Feb;132(2):204-10. doi: 10.1016/s0022-3476(98)70433-0.
To test the hypothesis that in a healthy pediatric population body mass index (BMI) (kilograms per meter square) is a valid measure of fatness that is independent of age for both sexes.
Total body fat (TBF) (in kilograms) and percent of body weight as fat (PBF) were estimated by dual energy x-ray absorptiometry (DXA) in 198 healthy Italian children and adolescents between 5 and 19 years of age. We developed multiple regression analysis models with TBF and percent body fat as dependent variables and BMI, age, and interaction terms as independent variables. Separate analyses were conducted for boys and girls.
BMI was strongly associated with TBF (R2 = 0.85 and 0.89 for boys and girls, respectively) and PBF (R2 =0.63 and 0.69 for boys and girls, respectively). Confidence limits on BMI-fatness association were wide, with individuals of similar BMI showing large differences in TBF and in PBF. Age was a significant covariate in all regression models. Addition of nonlinear terms for BMI did not substantially increase the R2 for TBF and PBF models in boys and girls.
Our results support the use of BMI as a fatness measure in groups of children and adolescents, although interpretation should be cautious when comparing BMI across groups that differ in age or when predicting a specific individual's TBF or PBF.
验证如下假设，即在健康儿童群体中，体重指数（BMI，千克/平方米）是衡量肥胖程度的有效指标，且该指标对于男女两性均与年龄无关。
采用双能X线吸收法（DXA）对198名年龄在5至19岁之间的健康意大利儿童和青少年的全身脂肪（TBF，千克）及体脂百分比（PBF）进行了估算。我们构建了以TBF和体脂百分比为因变量，BMI、年龄及交互项为自变量的多元回归分析模型。分别对男孩和女孩进行了分析。
BMI与TBF密切相关（男孩和女孩的R2分别为0.85和0.89），与PBF也密切相关（男孩和女孩的R2分别为0.63和0.69）。BMI与肥胖程度之间关联的置信区间较宽，BMI相似者的TBF和PBF差异很大。在所有回归模型中，年龄都是一个显著的协变量。添加BMI的非线性项并未显著提高男孩和女孩TBF及PBF模型的R2。
我们的结果支持将BMI用作儿童和青少年群体肥胖程度的衡量指标，不过，在比较不同年龄组的BMI或预测特定个体的TBF或PBF时，解释结果应谨慎。
