Metz Michael P
Division of Laboratory Medicine, Core Laboratory, Women's & Children's Hospital, 72 King William Road, North Adelaide, South Australia 5008, Australia.
Ann Clin Biochem. 2006 Sep;43(Pt 5):398-401. doi: 10.1258/000456306778520106.
The purpose of this study was to determine a cut-off above which a result is considered abnormal for 'spot' calcium-to-creatinine ratio (Ca/Cr) in urine in the paediatric age group. While the cut-offs are not well established, there are many published reports of urine Ca/Cr excretion ratio in the literature. Rather than undertaking a difficult, time-consuming, expensive, and ultimately redundant study, an analysis of these published works was undertaken to determine urine Ca/Cr cut-offs for the laboratory.
Fourteen studies reporting urine Ca/Cr ratio available in the literature were reviewed. Each study was abstracted for several characteristics. The data were plotted and the line of best fit describing the data was determined. Using the function describing the line, cut-offs by pertinent age were recalculated. These cut-offs were then compared to the original data and to in-house data.
The function describing the line of best fit was y=-0.3175 ln(x) +1.46 (y=Ca/Cr in mmol/mmol and x=age in years), r2=0.85. After consultation with the paediatric nephrologists and comparison with our in-house data, cut-offs for age groups of <1, 1-<2, 2-<5, 5-<10, and 10-18 years in mmol/mmol of 1.50, 1.25, 1.00, 0.70, and 0.60, respectively, were derived.
Using data from 14 published studies, suitable spot urine Ca/Cr cut-offs from birth to 18 years of age were determined.
本研究的目的是确定一个临界值，高于该临界值时，小儿年龄组尿“即时”钙肌酐比值（Ca/Cr）结果被视为异常。虽然临界值尚未完全确立，但文献中有许多关于尿Ca/Cr排泄率的报道。为了确定实验室的尿Ca/Cr临界值，未进行一项困难、耗时、昂贵且最终多余的研究，而是对这些已发表的研究进行了分析。
回顾了文献中14项报告尿Ca/Cr比值的研究。对每项研究提取了几个特征。绘制数据并确定描述数据的最佳拟合线。使用描述该线的函数，重新计算相关年龄的临界值。然后将这些临界值与原始数据和内部数据进行比较。
描述最佳拟合线的函数为y = -0.3175 ln(x) + 1.46（y为以mmol/mmol为单位的Ca/Cr，x为以岁为单位的年龄），r2 = 0.85。在与儿科肾病学家协商并与我们的内部数据比较后，得出<1岁、1 - <2岁、2 - <5岁、5 - <10岁和10 - 18岁年龄组以mmol/mmol为单位的临界值分别为1.50、1.25、1.00、0.70和0.60。
利用14项已发表研究的数据，确定了从出生到18岁合适的即时尿Ca/Cr临界值。
