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Random urinary calcium/creatinine ratio for screening hypercalciuria in children with hematuria
In Su Choi1, Eui Seok Jung, Young Earl Choi
1Department of Pediatrics, Chonnam National University Medical School and Hospital, Gwangju, Korea.
Insights
A random urine calcium/creatinine ratio is not reliable for screening hypercalciuria in children with hematuria. Standard 24-hour urine analysis is necessary for accurate diagnosis of this condition.
Area of Science:
- Pediatric Nephrology
- Urology
- Clinical Diagnostics
Background:
- Hypercalciuria is a frequent cause of unexplained isolated hematuria in children.
- Current diagnostic methods for hypercalciuria lack standardization.
- This study investigates the utility of random urinary calcium/creatinine ratio as a screening tool.
Purpose of the Study:
- To evaluate the effectiveness of random urinary calcium/creatinine ratio for screening hypercalciuria in pediatric hematuria cases.
- To determine if a random urine test can replace 24-hour urine collection for hypercalciuria diagnosis.
Main Methods:
- Prospective study of 264 children with primary hematuria.
- Comparison of random urinary calcium/creatinine ratio with 24-hour urinary calcium excretion.
- Statistical analysis including Pearson correlation, ROC curve, and multiple linear regression.
Main Results:
- A moderate correlation (r=0.584) was found between random and 24-hour urinary calcium/creatinine ratios.
- The optimal cutoff for random ratio (0.075 mg/mg) showed limited sensitivity (77.8%) and specificity (64.3%).
- Body mass index and 24-hour calcium excretion influenced the random ratio, with low explanatory power (r²=0.380).
Conclusions:
- Random urinary calcium/creatinine ratio is inadequate for screening hypercalciuria in children presenting with hematuria.
- Accurate diagnosis of hypercalciuria in these patients requires a 24-hour urinary analysis.
- Standardized diagnostic protocols are needed for pediatric hypercalciuria.
Background:
Hypercalciuria is one of the most common causes of unexplained isolated hematuria. The diagnostic methods for hypercalciuria have not yet been standardized. The aim of this study was to assess whether random urinary calcium/creatinine ratio could be used as a screening tool for hypercalciuria in children with hematuria.
Methods:
This prospective study included 264 children with primary hematuria for whom both random and 24 hr urinary evaluations were performed. Pearson correlation and ROC curve were used to assess the correlations. A multiple linear regression model was used to analyze effects of age, weight, height, body mass index, and body surface area on random urinary calcium/creatinine ratio.
Results:
There was a moderately strong correlation between random urinary calcium/creatinine ratio and 24 hr urinary calcium excretion (r=0.584, P<0.001). The most appropriate cutoff value of random urinary calcium/creatinine ratio for the estimation of hypercalciuria was 0.075 mg/mg (sensitivity, 77.8%; specificity, 64.3%; area under the curve, 0.778). Body mass index and 24 hr urinary calcium excretion significantly affected random urinary calcium/creatinine ratio with a low coefficient of determination (r(2)=0.380, P<0.001).
Conclusions:
Random urinary calcium/creatinine ratio is not suitable for screening hypercalciuria in children with hematuria. Twenty-four hour urinary analysis should be performed to diagnose hypercalciuria in children with hematuria.
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