Ellis K J, Nicolson M
USDA/ARS Children's Nutrition Research Center, Department Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.
Pediatr Res. 1997 Oct;42(4):484-8. doi: 10.1203/00006450-199710000-00010.
Leptin, a hormone secreted by adipocytes, is elevated in blood of obese adults. It is unknown whether the concentration is affected by gender, ethnicity, age, or stage of sexual maturation in children. We measured serum leptin levels in 183 children and 27 young adults using a double-antibody ELISA assay. Body fat mass (FM) and percent body fatness (%Fat) were determined by dual-energy x-ray absorptiometry. Correlations for serum leptin with FM, %Fat, and a body mass index were examined. Analyses of covariance were used to determine the effects of gender, ethnicity, and sexual maturation (Tanner stage). We found strong positive correlations (r = 0.56-0.88, p < 0.001) for serum leptin with body mass index. %Fat, and FM, which were gender-dependent (p < 0.001), but unaffected by ethnicity. At each Tanner stage, female subjects had higher serum leptin than male subjects (p < 0.001), and this difference remained significant (p < 0.001) when leptin was normalized for FM. For each gender, the mean leptin/FM ratios were relatively invariant during sexual maturation and no differences were observed between the oldest children (Tanner stage 5) and the young adults. The observation that female subjects have higher mean serum leptin and leptin/FM levels than male subjects at prepubertal ages may suggest that there are gender differences in leptin synthesis, clearance rates, bioactivity, and/or leptin transport.
瘦素是一种由脂肪细胞分泌的激素，在肥胖成年人的血液中含量升高。目前尚不清楚儿童的瘦素浓度是否受性别、种族、年龄或性成熟阶段的影响。我们使用双抗体酶联免疫吸附测定法测量了183名儿童和27名年轻成年人的血清瘦素水平。通过双能X线吸收法测定体脂肪量（FM）和体脂百分比（%Fat）。研究了血清瘦素与FM、%Fat和体重指数之间的相关性。采用协方差分析来确定性别、种族和性成熟（坦纳分期）的影响。我们发现血清瘦素与体重指数、%Fat和FM之间存在强正相关（r = 0.56 - 0.88，p < 0.001），这些相关性存在性别差异（p < 0.001），但不受种族影响。在每个坦纳分期，女性受试者的血清瘦素水平均高于男性受试者（p < 0.001），当瘦素经FM标准化后，这种差异仍然显著（p < 0.001）。对于每种性别，在性成熟过程中瘦素/FM的平均比值相对不变，在年龄最大的儿童（坦纳5期）和年轻成年人之间未观察到差异。青春期前女性受试者的平均血清瘦素和瘦素/FM水平高于男性受试者这一观察结果可能表明，瘦素的合成、清除率、生物活性和/或瘦素转运存在性别差异。
