INTRODUCTION The cystatin C (CysC) serum level is a marker of glomerular filtration rate and depends on age, gender, and pubertal stage. We hypothesize that CysC might overall reflect energy homeostasis and be regulated by components of the endocrine system and metabolites in pubertal adolescents. METHODS Serum CysC levels and further possible effector parameters in 5355 fasting, morning venous blood samples from 2035 healthy participants of the LIFE Child cohort study (age 8 to 18 years) were analyzed. Recruitment started in 2011, with probands followed up once a year. Linear univariate and stepwise multivariate regression analyses were performed. RESULTS Annual growth rate, serum levels of thyroid hormones, parathyroid hormone, insulin-like growth factor 1, hemoglobin A1c (HbA1c), uric acid, and alkaline phosphatase show relevant and significant associations with CysC serum concentrations (p <0.001). Furthermore, male probands' CysC correlated with the body mass index and testosterone among other sexual hormones. Multivariate analyses revealed that uric acid and HbA1c are associated variables of CysC independent from gender (p <0.001). In males, alkaline phosphatase (p <0.001) is additionally significantly associated with CysC. Thyroid hormones show significant correlations only in multivariate analyses in females (p <0.001). CONCLUSIONS The described associations strongly suggest an impact of children's metabolism on CysC serum levels. These alterations need to be considered in kidney diagnostics using CysC in adolescents. Additionally, further studies are needed on CysC in children.

中文翻译：

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胱抑素 C 与健康青春期青少年的新陈代谢有关。

简介 胱抑素 C (CysC) 血清水平是肾小球滤过率的标志物，取决于年龄、性别和青春期阶段。我们假设 CysC 可能整体反映能量稳态，并受青春期青少年内分泌系统成分和代谢物的调节。方法 对来自 LIFE 儿童队列研究的 2035 名健康参与者（年龄 8 至 18 岁）的 5355 份空腹、早晨静脉血样本中的血清 CysC 水平和进一步可能的效应参数进行分析。招募始于 2011 年，先证者每年跟进一次。进行线性单变量和逐步多变量回归分析。结果 年增长率、血清甲状腺激素、甲状旁腺激素、胰岛素样生长因子 1、血红蛋白 A1c (HbA1c)、尿酸、和碱性磷酸酶显示与 CysC 血清浓度相关且显着相关（p <0.001）。此外，男性先证者的 CysC 与体重指数和睾酮以及其他性激素相关。多变量分析显示，尿酸和 HbA1c 是 CysC 的相关变量，与性别无关 (p <0.001)。在男性中，碱性磷酸酶 (p <0.001) 还与 CysC 显着相关。甲状腺激素仅在女性的多变量分析中显示出显着相关性（p <0.001）。结论 所描述的关联强烈表明儿童新陈代谢对 CysC 血清水平的影响。在使用青少年 CysC 进行肾脏诊断时需要考虑这些改变。此外，还需要进一步研究儿童的 CysC。