Morrison J A, Alfaro M P, Khoury P, Thornton B B, Daniels S R
Department of Pediatrics, University of Cincinnati College of Medicine, Ohio, USA.
J Pediatr. 1996 Nov;129(5):637-42. doi: 10.1016/s0022-3476(96)70142-7.
To identify determinants of resting energy expenditure (REE) in black girls and white girls and to evaluate racial differences in REE.
Cross-sectional study of 98 girls (47 black and 51 white girls), ages 6 to 16 years.
Determinations of lean body mass, fat mass, and bone mass were made by dual-energy x-ray absorptiometry. Measurements of REE were made with the DeltaTrac metabolic monitor. Subjects fasted at least 3 hours before testing, had rested 30 minutes before the test, and had not engaged in strenuous activity for the previous 12 hours. Pubertal maturation was assessed with a three-stage scoring method: (1) prepubertal, (2) pubertal, but premenarcheal, and (3) postmenarcheal.
There were no significant differences in height, weight, lean body mass, or fat mass between the black and white subjects. Racial differences in total REE were also not significant, but REE standardized by weight was significantly greater in white girls (40.3 kcal/day) compared with black girls (35.5 kcal/day) (p = 0.001). Resting energy expenditure was positively and significantly correlated with all measures of body composition. Multiple regression analysis identified lean body mass, sexual maturation, and race as significant main effects. After controlling for lean body mass and maturation, black girls had significantly lower REE. The race-maturation interaction was of borderline significance (p = 0.09); prepubertal black girls had significantly lower REE (1156 kcal/day) than prepubertal white girls (1399 kcal/day), but racial differences in stages 2 and 3 were not statistically significant.
Lean body mass, maturation, and race are significant determinants of REE. Resting energy expenditure is significantly lower in black than white girls in the prepubertal stage. The cause of this racial difference in REE is not known; it is not explained by differences in anthropometric variables. Racial differences in REE could explain in part the earlier onset of puberty in black girls compared with white girls and could be a factor in the difference in obesity in black and white women.
确定黑人女孩和白人女孩静息能量消耗（REE）的决定因素，并评估REE的种族差异。
对98名6至16岁女孩（47名黑人女孩和51名白人女孩）进行横断面研究。
采用双能X线吸收法测定瘦体重、脂肪量和骨量。使用DeltaTrac代谢监测仪测量REE。受试者在测试前至少禁食3小时，测试前休息30分钟，且在过去12小时内未进行剧烈活动。采用三阶段评分法评估青春期成熟度：（1）青春期前，（2）青春期但月经初潮前，（3）月经初潮后。
黑人和白人受试者在身高、体重、瘦体重或脂肪量方面无显著差异。总REE的种族差异也不显著，但按体重标准化后的REE在白人女孩（40.3千卡/天）中显著高于黑人女孩（35.5千卡/天）（p = 0.001）。静息能量消耗与所有身体成分指标呈正相关且显著相关。多元回归分析确定瘦体重、性成熟和种族为显著的主要影响因素。在控制了瘦体重和成熟度后，黑人女孩的REE显著较低。种族 -成熟度相互作用具有临界显著性（p = 0.09）；青春期前黑人女孩的REE（1156千卡/天）显著低于青春期前白人女孩（1399千卡/天），但在第2和第3阶段的种族差异无统计学意义。
瘦体重、成熟度和种族是REE的重要决定因素。青春期前黑人女孩的静息能量消耗显著低于白人女孩。这种REE种族差异的原因尚不清楚；人体测量变量的差异无法解释这一现象。REE的种族差异可能部分解释了黑人女孩青春期比白人女孩更早开始，并且可能是黑人和白人女性肥胖差异的一个因素。
