Spot Urinary Citrate Normograms in Children.

Area of Science:

• Pediatric Nephrology
• Urology
• Clinical Chemistry

Background:

• Urinary citrate plays a vital role in inhibiting kidney stone formation (nephrolithiasis).
• Oral citrate supplementation is a common preventative strategy for kidney stones.
• Establishing normative data for urinary citrate is essential for pediatric stone disease management.

Purpose of the Study:

• To determine the normograms for urinary citrate, creatinine, and their ratio in healthy children.
• To provide reference ranges for spot urine citrate-to-creatinine ratios across different pediatric age groups and sexes.
• To investigate potential age-related variations in urinary citrate excretion.

Main Methods:

• Analysis of spot urine samples from 237 healthy children aged 1 month to 14 years.
• Statistical evaluation including mean, standard deviation, median, and 5th/95th percentiles.
• Comparison of urinary citrate-to-creatinine ratios across age groups and sexes using ANOVA and t-tests.

Main Results:

• Established normograms for urinary citrate and creatinine levels and their ratio in healthy children.
• Identified a significantly higher urinary citrate-to-creatinine ratio in children younger than 18 months (lower cutoff 915 mg/g).
• Reported lower cutoffs for older boys (109 mg/g) and girls (126 mg/g).

Conclusions:

• The study provides essential normative data for urinary citrate-to-creatinine ratios in pediatric populations.
• Age-specific reference ranges are crucial, with infants showing distinct patterns potentially linked to diet.
• These findings aid in the diagnosis and management of pediatric kidney stone disease.