Arslanian S, Suprasongsin C, Kalhan S C, Drash A L, Brna R, Janosky J E
Division of Pediatric Endocrinology, Metabolism and Diabetes Mellitus, Children's Hospital, University of Pittsburgh, PA 15213, USA.
Metabolism. 1998 Mar;47(3):309-12. doi: 10.1016/s0026-0495(98)90262-1.
Leptin has been demonstrated to reflect body fat mass (FM) in humans, but the regulation of leptin levels during childhood growth and development is poorly understood. We studied the relation between plasma leptin, fasting insulin, insulin sensitivity, and resting energy expenditure in 22 healthy prepubertal children and 27 adolescents. Body composition was assessed by the H2(18)O-dilution principle, insulin sensitivity by a hyperinsulinemic (40 mU/m2/min)-euglycemic clamp, and energy expenditure by indirect calorimetry. Plasma leptin in prepubertal children (9.3 +/- 2.0 ng/mL) was not different from that in pubertal adolescents (10.9 +/- 2.2 ng/mL). Plasma leptin correlated with FM (r = .77, P < .001). There were no gender differences in leptin after controlling for FM differences. In prepubertal and pubertal subjects, plasma leptin correlated with fasting insulin independently of FM (r = .60, P < .001), but did not correlate with insulin sensitivity independently of body fat content. Leptin showed no relationship to resting energy expenditure after adjusting for body composition. The present cross-sectional evaluation of normal children shows that (1) plasma leptin reflects body fat content, (2) leptin concentrations are similar between prepubertal children and pubertal adolescents, (3) there are no gender differences in leptin independent of adiposity, and (4) leptin correlates with fasting insulin but not with insulin sensitivity. Contrary to animal data, our cross-sectional results in healthy children do not suggest a role for leptin in puberty or a female-related leptin resistance as reported in adults. It remains to be determined at which stage of human development the sexual dimorphism in leptin becomes evident.
瘦素已被证明可反映人体的体脂肪量（FM），但人们对儿童生长发育过程中瘦素水平的调节了解甚少。我们研究了22名健康青春期前儿童和27名青少年的血浆瘦素、空腹胰岛素、胰岛素敏感性和静息能量消耗之间的关系。通过H2(18)O稀释原理评估身体成分，通过高胰岛素血症（40 mU/m2/分钟）-正常血糖钳夹评估胰岛素敏感性，通过间接测热法评估能量消耗。青春期前儿童的血浆瘦素（9.3±2.0 ng/mL）与青春期青少年的血浆瘦素（10.9±2.2 ng/mL）无差异。血浆瘦素与体脂肪量相关（r = 0.77，P < 0.001）。在控制体脂肪量差异后，瘦素不存在性别差异。在青春期前和青春期受试者中，血浆瘦素与空腹胰岛素独立相关（与体脂肪量无关，r = 0.60，P < 0.001），但与胰岛素敏感性独立相关（与体脂肪含量无关）。在调整身体成分后，瘦素与静息能量消耗无关系。对正常儿童的本次横断面评估表明：（1）血浆瘦素反映体脂肪含量；（2）青春期前儿童和青春期青少年的瘦素浓度相似；（3）独立于肥胖情况，瘦素不存在性别差异；（4）瘦素与空腹胰岛素相关，但与胰岛素敏感性无关。与动物数据相反，我们在健康儿童中的横断面结果并不表明瘦素在青春期起作用，也不表明存在如成人中报道的与女性相关的瘦素抵抗。瘦素的性别二态性在人类发育的哪个阶段变得明显仍有待确定。
