Abstract：
OBJECTIVE: Sarcopenia is a serious problem in adults and children. However, limited modalities are available for diagnosing pediatric sarcopenia. The serum creatinine to cystatin C ratio (Cre/CysC ratio) is a promising method for muscle quantification, although its clinical significance in the pediatric population is unknown. This study aimed to evaluate the relationship between the Cre/CysC ratio and physical performance.
METHODS: This was a single-center retrospective study. Patients aged <15 years who had visited the University of Tokyo Hospital for measurements of serum creatinine and cystatin C levels, body height, and body weight were included. The patients were assigned according to their age (<2 or ≥2 years), and the relationship between the Cre/CysC ratio and physical performance at the time of measurement was analyzed.
RESULTS: We included 266 patients, revealing a significant relationship between Cre/CysC ratio and physical performance in children aged ≥2 years (p < 0.001) but not in children aged <2 years (p = 0.42). The repeater-operator curve analysis of Cre/CysC to predict bedridden status showed good performance (the area under the curve was 0.82 (95% CI, 0.75-0.89)) and the cut-off value 0.44 had good accuracy (sensitivity 0.87, specificity 0.61).
CONCLUSIONS: The Cre/CysC ratio was a significant marker of impaired physical performance, and a Cre/CysC ratio <0.44 accurately predicted bedridden status in children aged >2 years.
METHODS: This was a single-center retrospective study. Patients aged <15 years who had visited the University of Tokyo Hospital for measurements of serum creatinine and cystatin C levels, body height, and body weight were included. The patients were assigned according to their age (<2 or ≥2 years), and the relationship between the Cre/CysC ratio and physical performance at the time of measurement was analyzed.
RESULTS: We included 266 patients, revealing a significant relationship between Cre/CysC ratio and physical performance in children aged ≥2 years (p < 0.001) but not in children aged <2 years (p = 0.42). The repeater-operator curve analysis of Cre/CysC to predict bedridden status showed good performance (the area under the curve was 0.82 (95% CI, 0.75-0.89)) and the cut-off value 0.44 had good accuracy (sensitivity 0.87, specificity 0.61).
CONCLUSIONS: The Cre/CysC ratio was a significant marker of impaired physical performance, and a Cre/CysC ratio <0.44 accurately predicted bedridden status in children aged >2 years.
摘要：
目的：肌肉减少症是成人和儿童的严重问题。然而,诊断小儿肌少症的方法有限.血清肌酐与胱抑素C比值（Cre/CysC比值）是一种有前途的肌肉定量方法，尽管其在儿科人群中的临床意义尚不清楚。本研究旨在评估Cre/CysC比率与物理性能之间的关系。
方法：这是一项单中心回顾性研究。年龄<15岁的患者曾到东京大学医院进行血清肌酐和胱抑素C水平的测量，身体高度,和体重都包括在内。根据患者的年龄（<2岁或≥2岁）进行分组，并分析了Cre/CysC比值与测量时物理性能的关系。
结果：我们纳入了266例患者，揭示Cre/CysC比率与≥2岁儿童的身体表现之间存在显着关系（p<0.001），而<2岁儿童则没有（p=0.42）。Cre/CysC预测卧床状态的重复操作员曲线分析显示良好的性能（曲线下面积为0.82（95％CI，0.75-0.89）），临界值0.44具有良好的准确性（敏感性0.87，特异性0.61）。
结论：Cre/CysC比率是身体机能受损的重要标志，Cre/CysC比值<0.44可以准确预测2岁以上儿童的卧床状态。
方法：这是一项单中心回顾性研究。年龄<15岁的患者曾到东京大学医院进行血清肌酐和胱抑素C水平的测量，身体高度,和体重都包括在内。根据患者的年龄（<2岁或≥2岁）进行分组，并分析了Cre/CysC比值与测量时物理性能的关系。
结果：我们纳入了266例患者，揭示Cre/CysC比率与≥2岁儿童的身体表现之间存在显着关系（p<0.001），而<2岁儿童则没有（p=0.42）。Cre/CysC预测卧床状态的重复操作员曲线分析显示良好的性能（曲线下面积为0.82（95％CI，0.75-0.89）），临界值0.44具有良好的准确性（敏感性0.87，特异性0.61）。
结论：Cre/CysC比率是身体机能受损的重要标志，Cre/CysC比值<0.44可以准确预测2岁以上儿童的卧床状态。
