Urinary calcium creatinine ratio and hypercalciuria

Area of Science:

• Pediatric Nephrology
• Clinical Chemistry

Background:

• Hypercalciuria in children can indicate underlying renal or metabolic conditions.
• Establishing normative data for urinary calcium-creatinine ratio (Uca/Ucr) is crucial for accurate diagnosis in pediatric populations.

Purpose of the Study:

• To determine the prevalence of hypercalciuria in a general pediatric population.
• To establish the normal range for urinary calcium-creatinine ratio (Uca/Ucr) in children aged 5-12 years.
• To assess the relationship between Uca/Ucr, age, and sex in children.

Main Methods:

• Analysis of random urine samples from 352 children (5-12 years old) without predisposing factors for secondary hypercalciuria.
• Quantification of urinary calcium and creatinine using a colorimetric method.
• Calculation of the urinary calcium-creatinine ratio (Uca/Ucr) and statistical analysis to determine the upper limit of normal and prevalence.

Main Results:

• The distribution of Uca/Ucr in the studied pediatric cohort was skewed, mirroring patterns observed in Western children.
• The mean Uca/Ucr was 0.10 with a standard deviation of 0.094.
• Hypercalciuria (defined as Uca/Ucr > 0.29, mean + 2SD) was identified in 6.5% of the children, with no significant association with age or sex.

Conclusions:

• The study establishes a reference range for Uca/Ucr in children aged 5-12 years.
• A 6.5% prevalence of hypercalciuria was observed in the general pediatric population, suggesting a need for awareness.
• Urinary calcium-creatinine ratio is a valuable screening tool for hypercalciuria in children, independent of age and sex.