Reiterer E E, Sudi K M, Mayer A, Limbert-Zinterl C, Stalzer-Brunner C, Füger G, Borkenstein M H
Department of Pediatrics, Karl-Franzens University Graz, Austria.
J Pediatr Endocrinol Metab. 1999 Nov-Dec;12(6):853-62. doi: 10.1515/JPEM.1999.12.6.853.
Girls have higher leptin concentrations than boys at all stages of biological development and this is also seen in the state of obesity. Little is known about whether gender and biological development of obese children influence changes in leptin associated with a short-term weight reduction program.
To study whether leptin concentration, body composition and insulin levels in obese children were influenced by a 3-week intervention program including diet and sports.
Sixty-two obese children (32 boys and 30 girls) were examined before and after the intervention program. Body composition was measured by bioelectrical impedance and BMI-SDS was calculated. Serum leptin and serum insulin were determined by RIA.
Girls had higher leptin levels than boys, before and after the weight reduction program. Body mass, fat mass (FM), leptin and insulin were decreased after the intervention in both sexes. We found a greater change in serum leptin in girls but the change in FM was of greater magnitude in boys. However, percentage changes in leptin were not significantly different between the sexes. Before the intervention, leptin concentrations were correlated with %FM, FM and moderately with BMI-SDS in all children. Only in pubertal boys did correlation of leptin with %FM increase after the intervention (from r=0.57 to r=0.75, p<0.01). Changes in leptin were found to be associated with initial leptin values in boys (r=0.95, p<0.01) and in girls (r=0.93, p<0.01), independent of Tanner stages.
Serum leptin levels were positively correlated with adiposity in obese children and a diet and sports intervention program decreased serum leptin, insulin and body fat in all children. Changes in leptin were best described by the initial leptin concentration. The increase in correlation of leptin with %FM in obese pubertal boys after the intervention could have its underlying mechanism in an increased sensitivity to leptin and anabolic hormones.
在生物发育的各个阶段，女孩的瘦素浓度均高于男孩，肥胖状态下亦是如此。对于肥胖儿童的性别及生物发育是否会影响与短期减重计划相关的瘦素变化，目前知之甚少。
研究为期3周的饮食和运动干预计划是否会影响肥胖儿童的瘦素浓度、身体成分及胰岛素水平。
在干预计划前后对62名肥胖儿童（32名男孩和30名女孩）进行检查。通过生物电阻抗测量身体成分并计算BMI-SDS。采用放射免疫分析法测定血清瘦素和血清胰岛素。
在减重计划前后，女孩的瘦素水平均高于男孩。干预后，男女的体重、脂肪量（FM）、瘦素和胰岛素均有所下降。我们发现女孩血清瘦素的变化更大，但男孩的FM变化幅度更大。然而，瘦素的百分比变化在性别之间无显著差异。干预前，所有儿童的瘦素浓度与%FM、FM呈正相关，与BMI-SDS呈中度相关。仅在青春期男孩中，干预后瘦素与%FM的相关性增加（从r = 0.57增至r = 0.75，p < 0.01）。发现男孩（r = 0.95，p < 0.01）和女孩（r = 0.93，p < 0.01）的瘦素变化与初始瘦素值相关，与坦纳分期无关。
肥胖儿童的血清瘦素水平与肥胖程度呈正相关，饮食和运动干预计划可降低所有儿童的血清瘦素、胰岛素和体脂。瘦素的变化最好用初始瘦素浓度来描述。干预后肥胖青春期男孩中瘦素与%FM相关性的增加可能其潜在机制在于对瘦素和合成代谢激素的敏感性增加。
