Normal Reference Range of the Urinary Calcium/Creatinine Ratio in Healthy Children

Area of Science:

• Pediatric Nephrology
• Clinical Biochemistry
• Public Health

Background:

• Accurate reference ranges for urinary calcium-to-creatinine ratio (UCa/Cr) are essential for diagnosing pediatric hypercalciuria.
• Existing UCa/Cr reference ranges may not be applicable to diverse pediatric populations.
• Establishing local, age-specific data is crucial for effective clinical management.

Purpose of the Study:

• To determine age-specific normal reference ranges for urinary calcium-to-creatinine ratio (UCa/Cr).
• To study healthy children aged 7-12 years in the urban Kolhapur region.
• To provide data for accurate diagnosis and management of calcium disorders in children.

Main Methods:

• 358 healthy children aged 7-12 years were enrolled.
• Second-morning, non-fasting urine samples were collected.
• Urinary calcium was analyzed using the Cresolpthalein complexone spectrophotometric method, and creatinine by the Modified Jaffe's method.

Main Results:

• The mean UCa/Cr ranged from 0.12 ± 0.08 mg/mg at age 7 to 0.09 ± 0.02 mg/mg at age 12.
• The highest mean UCa/Cr was observed at age 8 (0.15 ± 0.05 mg/mg).
• The normal reference range for UCa/Cr in this population was 0.05 ± 0.192 mg/mg, showing a decline with age.

Conclusions:

• Population-specific reference values for UCa/Cr are vital for diagnosing hypercalciuria in children.
• This study provides essential clinical data for the Kolhapur region.
• Early detection and management of calcium metabolism disorders in children are facilitated by these findings.