Supplementary Material for: Determinants of Advanced Bone Age in Childhood Obesity

<i>Background:</i> Childhood obesity is associated with advanced bone age (BA). Previous studies suggest that androgens, oestrogens, sex hormone-binding globulin, and insulin are responsible for this phenomenon, but results are contradictory and might be biased by confounders. We aim to elucidate this matter by applying a multivariate approach. <i>Method:</i> We performed a correlation analysis of BA standard deviation score (SDS) with age- and sex-specific SDS for androgens, oestrogens, and with indicators of insulin secretion derived from oral glucose tolerance testing, in a group of obese children. A multivariate analysis was performed to investigate which parameters were independently predictive of BA SDS. <i>Results:</i> In this cohort (<i>n</i> = 101; mean age 10.9 years; mean BA 11.8 years; mean BMI SDS 3.3), BMI SDS was significantly correlated to BA SDS (<i>r</i> = 0.55, <i>p</i> &lt; 0.001). In a regression analysis in the total cohort (<i>B</i> = 0.27, <i>p</i> &lt; 0.001) as well as in females (<i>B</i> = 0.34, <i>p</i> = 0.042), males (<i>B</i> = 0.31, <i>p</i> = 0.006), and pubertal children (<i>B</i> = 0.32, <i>p</i> = 0.046), dehydroepiandrosterone sulphate (DHEAS) showed a positive, independent association with BA SDS. No association with indicators of insulin secretion was found. <i>Conclusion:</i> BMI SDS is highly correlated to BA SDS in obese children. Increased DHEAS has a central role in advanced BA in obese children.

背景：儿童肥胖与骨龄（Bone Age, BA）超前存在关联。既往研究认为雄激素、雌激素、性激素结合球蛋白及胰岛素是该现象的潜在成因，但相关研究结果存在矛盾，且可能受混杂因素影响而产生偏倚。本研究旨在通过多变量分析方法阐明这一问题。
方法：本研究针对肥胖儿童队列，开展了骨龄标准差评分（BA SDS）与年龄及性别特异性的雄激素、雌激素标准差评分，以及口服葡萄糖耐量试验衍生的胰岛素分泌指标的相关性分析，并通过多变量分析探究可独立预测BA SDS的参数。
结果：本队列共纳入101名受试者，平均年龄10.9岁，平均骨龄11.8岁，平均体重指数标准差评分（BMI SDS）为3.3。BMI SDS与BA SDS呈显著正相关（r = 0.55，p < 0.001）。在全队列（回归系数B = 0.27，p < 0.001）、女性亚组（B = 0.34，p = 0.042）、男性亚组（B = 0.31，p = 0.006）及青春期儿童亚组（B = 0.32，p = 0.046）的回归分析中，硫酸脱氢表雄酮（dehydroepiandrosterone sulphate, DHEAS）与BA SDS呈独立的正向关联。未发现与胰岛素分泌指标存在显著关联。
结论：肥胖儿童的BMI SDS与BA SDS呈显著相关；血清DHEAS水平升高在肥胖儿童骨龄超前的发病机制中发挥核心作用。