Matsuoka H, Fors H, Bosaeus I, Rosberg S, Albertsson-Wikland K, Bjarnason R
International Pediatric Growth Research Center, Department of Pediatrics, University of Göteborg, Sweden.
Eur J Endocrinol. 1999 Jan;140(1):35-42. doi: 10.1530/eje.0.1400035.
The aim of this study was to follow changes in body composition, estimated by dual-energy X-ray absorptiometry (DXA), in relation to changes in leptin during the first year of GH therapy in order to test the hypothesis that leptin is a metabolic signal involved in the regulation of GH secretion in children.
In total, 33 prepubertal children were investigated. Their mean (S.D.) chronological age at the start of GH treatment was 11.5 (1.6) years, and their mean height was -2.33 (0.38) S.D. scores (SDS). GH was administered subcutaneously at a daily dose of 0.1 (n=26) or 0.2 (n=7) IU/kg body weight. Ten children were in the Swedish National Registry for children with GH deficiency, and twenty-three children were involved in trials of GH treatment for idiopathic short stature. Spontaneous 24-h GH secretion was studied in 32 of the children. In the 24-h GH profiles, the maximum level of GH was determined and the secretion rate estimated by deconvolution analysis (GHt). Serum leptin levels were measured at the start of GH treatment and after 10 and 30 days and 3, 6 and 12 months of treatment. Body composition measurements, by DXA, were performed at baseline and 12 months after the onset of GH treatment.
After 12 months of GH treatment, mean height increased from -2.33 to -1.73 SDS and total body fat decreased significantly by 3.0 (3.3)%. Serum leptin levels were decreased significantly at all time points studied compared with baseline. There was a significant correlation between the change in total body fat and the change in serum leptin levels during the 12 months of GH treatment, whereas the leptin concentration per unit fat mass did not change. In a multiple stepwise linear regression analysis with 12 month change in leptin levels as the dependent variable, the percentage change in fat over 12 months, the baseline fat mass (%) of body mass and GHt accounted for 24.0%, 11.5% and 12.2% of the variability respectively.
There are significant correlations between changes in leptin and fat and endogenous GH secretion in short children with various GH secretory capacities. Leptin may be the messenger by which the adipose tissue affects hypothalamic regulation of GH secretion.
本研究旨在追踪生长激素（GH）治疗第一年期间，通过双能X线吸收法（DXA）估算的身体成分变化与瘦素变化的关系，以检验瘦素是参与儿童GH分泌调节的代谢信号这一假说。
共对33名青春期前儿童进行了研究。他们开始GH治疗时的平均（标准差）实足年龄为11.5（1.6）岁，平均身高为-2.33（0.38）标准差评分（SDS）。GH以每日0.1（n = 26）或0.2（n = 7）IU/kg体重的剂量皮下注射。10名儿童在瑞典国家生长激素缺乏症儿童登记处，23名儿童参与了特发性矮小症GH治疗试验。对其中32名儿童研究了自发性24小时GH分泌情况。在24小时GH谱中，测定GH的最高水平并通过去卷积分析（GHt）估算分泌率。在GH治疗开始时以及治疗10天、30天、3个月、6个月和12个月后测量血清瘦素水平。通过DXA进行身体成分测量在基线时以及GH治疗开始后12个月进行。
GH治疗12个月后，平均身高从-2.33 SDS增加到-1.73 SDS，全身脂肪显著减少3.0（3.3）%。与基线相比，在所有研究时间点血清瘦素水平均显著降低。在GH治疗的12个月期间，全身脂肪变化与血清瘦素水平变化之间存在显著相关性，而单位脂肪量中的瘦素浓度未改变。在以瘦素水平12个月变化为因变量的多元逐步线性回归分析中，12个月内脂肪百分比变化、体重中基线脂肪量（%）和GHt分别占变异性的24.0%、11.5%和12.2%。
在具有不同GH分泌能力的矮小儿童中，瘦素和脂肪变化与内源性GH分泌之间存在显著相关性。瘦素可能是脂肪组织影响下丘脑GH分泌调节的信使。
