Related Experiment Videos
Urinary calcium excretion in healthy Thai children
P Vachvanichsanong1, L Lebel, E S Moore
1Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat-Yai, Thailand. Vprayong@ratree.psu.ac.th
Insights
This study established age-specific reference values for urinary calcium/creatinine ratios in healthy Thai children. Elevated ratios correlated with higher sodium excretion, but routine urinalysis is not a reliable indicator of hypercalciuria.
Area of Science:
- Pediatric Nephrology
- Clinical Chemistry
- Public Health
Background:
- Establishing age-specific reference values for urinary calcium/creatinine ratios (UCa/Cr) is crucial for diagnosing pediatric hypercalciuria.
- Previous studies have not comprehensively defined these values for healthy children in Southeast Asia.
Purpose of the Study:
- To determine age-specific reference values for random, non-fasting urinary calcium/creatinine ratios (UCa/Cr) in healthy Southern Thai children.
- To investigate the relationship between UCa/Cr and other urinary parameters like sodium and potassium.
Main Methods:
- A cross-sectional study involving 488 healthy children aged 17 days to 15 years in Southern Thailand.
- Collection of non-fasting urine samples, divided into six age groups.
- Analysis of urinary calcium, creatinine, sodium, and potassium levels; hypercalciuria defined as exceeding the 95th percentile within each age group.
Main Results:
- Age-specific 95th percentiles for UCa/Cr were established, showing a decrease with age.
- Hypercalciuria was identified in 22 children; pyuria, hematuria, and proteinuria were not more prevalent in this group.
- Higher UCa/Cr correlated with increased urinary sodium/creatinine (UNa/Cr) and urinary sodium/potassium (UNa/K) ratios.
Conclusions:
- The study provides essential reference ranges for UCa/Cr in healthy Thai children.
- Routine urinalysis parameters (pyuria, hematuria, proteinuria) are not effective indicators for identifying hypercalciuria.
- Elevated UCa/Cr in children may be associated with increased sodium excretion.
Abstract:
The objective of this study was to determine age-specific reference values for urinary calcium/creatinine ratios (UCa/Cr) of children in southern Thailand. Non-fasting urine samples were collected from a random population of 488 healthy children (282 males, 206 females) ranging in age from 17 days to 15 years. Samples were divided into six groups by age. Subjects whose calcium levels exceeded the 95th percentile within each age group were classified as having hypercalciuria. Pyuria, hematuria, proteinuria, urinary sodium, and potassium levels in children with normal UCa/Cr were compared with levels in children with high UCa/Cr. The 95th percentiles for UCa/Cr (mg/mg) by age were: <6 months, 0.75; 6 months to <12 months, 0.64; 12 months to <2 years, 0.40; 2 years to <5 years, 0.38; 5 years to <10 years, 0.29; and 10 years to <15 years, 0.26. Pyuria, hematuria, and proteinuria were no more prevalent in the 22 children with hypercalciuria than in children with normal urinary calcium levels. Urinary sodium/creatinine ratios (UNa/Cr) and urinary sodium/potassium ratios (UNa/K) were correlated with UCa/Cr (r=0.41, P<0.0001 and r=0.24, P<0.0001, respectively). Urinary potassium/creatinine ratios (UK/Cr) were not (r=0.05, P>0.1)). Children with high UCa/Cr ratios also had higher UNa/Cr and UNa/K (5.6+/-7.1 vs. 2.6+/-1.5, P<0.001 and 5.4+/-2.3 vs. 2.5+/-0.23, P<0.05, respectively). The study established reference values for random, non-fasting UCa/Cr for healthy Thai children and indicated that urinalysis is not a good indicator of hypercalciuria.