Normal urinary calcium/creatinine ratios in Turkish children.

A random urine calcium/creatinine ratio (UCa/Cr) is of practical use in screening for hypercalciuria. However, due to worldwide variations, reference values for the pediatric population are not yet well established. Furthermore, no study has been conducted to establish normal UCa/Cr values in Turkish children. The objectives of the present study were to set normal values of random UCa/Cr by age in the pediatric population of Istanbul City. A total of 324 healthy children of both genders were enrolled in the study. They were divided into four age groups as follows: (1) < 7 months, (2) 8-18 months, (3) 19 months to 6 years, and (4) 7-14 years. A non-fasting random urine specimen from each subject was analyzed for calcium and creatinine. The median UCa/Cr values were 0.19, 0.20, 0.14 and 0.10 respectively. The data showed a strong inverse relationship with age. The age-dependent 95th percentiles of UCa/Cr values were 0.76, 0.60, 0.69 and 0.24 respectively. The child's age and geographic location should be taken into consideration when interpreting UCa/Cr ratio.