Asymptomatic hypercalciuria: prevalence and metabolic characteristics

Area of Science:

• Pediatric Nephrology
• Urology
• Metabolic Bone Disease

Background:

• Hypercalciuria is a significant risk factor for kidney stone formation in pediatric populations.
• Early identification of hypercalciuria is crucial for preventing urolithiasis in children.

Purpose of the Study:

• To determine the prevalence of hypercalciuria in healthy Turkish children.
• To investigate the characteristics and potential risk factors associated with hypercalciuria in this cohort.

Main Methods:

• Screening of 592 healthy Turkish children (aged 3 months to 16 years) for hypercalciuria using urinary calcium/creatinine (UCa/Cr) ratios in second-morning urine samples.
• Performing oral calcium-loading tests on identified hypercalciuric children to differentiate subtypes.
• Assessing family history of urolithiasis and correlating urinary calcium with urinary magnesium levels.

Main Results:

• Hypercalciuria was detected in 17 children (2.9%), with a near-equal distribution between boys and girls.
• Oral calcium-loading tests indicated absorptive hypercalciuria in 2 out of 7 children tested.
• A 50% prevalence of a family history of urolithiasis was observed in asymptomatic hypercalciuric children.
• Median UCa/Cr and urinary magnesium/creatinine (UMg/Cr) ratios were 0.11 and 0.10, respectively, with 97th percentiles of 0.32 and 0.23.
• UCa/Cr ratio showed a positive correlation with UMg/Cr ratio (r = 0.44) and was independent of age and sex.

Conclusions:

• Hypercalciuria affects a notable percentage of healthy Turkish children, highlighting the importance of screening.
• Family history appears to be a significant risk factor for hypercalciuria in children.
• The correlation between urinary calcium and magnesium warrants further investigation in pediatric hypercalciuria.