身材矮小儿童和青少年血脂水平与生长激素激发试验峰值的相关性研究

背景　矮小症是儿童生长发育的常见问题，生长激素缺乏症（GHD）是多见的类型，其诊断依赖于生长激素激发试验。研究表明，血脂水平可能是影响生长激素激发试验反应变异性的因素之一。然而，类似的研究尚未在儿童和青少年中进行。目的　调查身材矮小儿童和青少年血脂水平与生长激素激发试验峰值之间的关系，为影响身材矮小患儿生长激素激发试验高峰的可能因素提供证据。方法　回顾性分析2013—2017年济宁医学院附属医院内分泌科收治的1 009例身材矮小的中国儿童和青少年的临床资料，根据身高第3百分位数分为矮小症595例，身材偏矮414例，进行分层分析。均完成左旋多巴生长激素激发试验（L-dopa试验）或胰岛素低血糖生长激素激发试验（ITT），测量身高、体质量、血脂水平和其他相关指标。采用单因素及多元线性回归分析生长激素激发试验峰值与人体测量指标和血脂水平的相关性。结果　L-dopa试验峰值（PEAK1）与体质量、体质指数（BMI）、BMI标准差数值（SDS）、三酰甘油（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、极低密度脂蛋白胆固醇（VLDL-C）、丙氨酸氨基转移酶（ALT）呈负相关，与胰岛素样生长因子1（IGF-1）呈正相关（P<0.05）；ITT峰值（PEAK2）与BMI SDS、TC、HDL-C呈负相关，与女性、年龄、骨龄、身高、体质量、血红蛋白（Hb）、IGF-1呈正相关（P<0.05）。多元线性回归分析结果显示，PEAK1与TG和HDL-C呈负相关（P<0.05）；PEAK2与HDL-C呈负相关（P<0.05）。按照身高第三百分位分为矮小症595例，身材偏矮414例，进行分层分析。对于矮小症患儿，PEAK1与HDL-C呈负相关（P<0.05）。对于身材偏矮患儿，PEAK1与TG、HDL-C呈负相关（P<0.05）；PEAK2与HDL-C呈负相关（P<0.05）。结论　血脂水平影响生长激素对生长激素激发试验的反应性，建议在进行生长激素激发试验之前应低脂饮食，这可能会提高诊断GHD的准确性。

Correlation between Serum Lipid and Peak Growth Hormone at a Stimulation Test in Children and Adolescents with Short Stature

Background　Short stature is a common problem in children's growth and development，which is caused mainly by growth hormone deficiency （GHD），and its diagnosis depends on the growth hormone（GH） stimulation test.Studies have shown that serum lipid levels may be one of the factors that influence the variability of GH response at a stimulation test.However，similar studies have not been conducted in child population yet.Objective　To investigate the relationship between serum lipids and peak GH at a stimulation test in children and adolescents with short stature，to provide evidence for possible factors influencing the stimulated peak GH in such populations.Methods　A retrospective analysis was performed on 1 009 Chinese children and adolescents with short stature recruited from Department of Endocrinology，Jining Medical University，from 2013 to 2017.Clinical data such as height，body weight，and other anthropometric parameters as well as serum lipid profile，results of GH stimulation test with L-dopa or insulin-induced hypoglycemia test （insulin tolerance test，ITT） were collected.Stratified analysis was performed on two subgroups 〔dwarfism subgroup （n=595） and slightly undersized subgroup （n=414）〕 divided by the third height percentile.Univariate and multiple linear regression analyses were used to explore the correlations of peak GH at a stimulation test with anthropometric parameters and serum lipids.Results　The peak GH value at the stimulation test with L-dopa （PEAK1） was negatively correlated with body weight，BMI，BMI SDS，TG，TC，HDL-C，LDL-C，VLDL-C，and ALT，but positively correlated with IGF-1 （P<0.05）；the peak GH value at the ITT （PEAK2） was negatively correlated with BMI SDS，TC，and HDL-C，but positively correlated with female，age，bone age，height，body weight，Hb and IGF-1 （P<0.05）．Multiple linear regression analysis showed that PEAK1 was negatively correlated with both TG and HDL-C （P<0.05），and PEAK2 was negatively correlated with HDL-C （P<0.05）．In the dwarfism subgroup，PEAK1 showed a negative correlation with HDL-C （P<0.05）．In the slightly undersized subgroup，PEAK1 demonstrated a negative correlation with both TG and HDL-C （P<0.05），and PEAK2 demonstrated a negative correlation with HDL-C （P<0.05）．Conclusion　This study suggests that serum lipids affect the response of GH at the stimulation test.It is suggested that low-fat diet should be adopted before the GH stimulation test，which may improve the accuracy of diagnosis of GHD.