Background: Idiopathic hypercalciuria (IH) is characterized by the excess excretion of calcium, despite normal levels of calcium in the blood and no apparent cause. In recent years, this metabolic disorder is become more common to diagnose in children and can cause various urinary symptoms.
Objective: To determine the prevalence of idiopathic hypercalciuria in children with different urinary symptoms, recurrent unexplained fever, or abdominal pain and to explore the risk factors and symptoms associated with childhood idiopathic hypercalciuria.
Methods: This descriptive cross-sectional study that was conducted from May to November 2022 in a Pediatric Nephrology and General Pediatric Clinic at Bab Al-sharia Hospital Al-Azhar University Hospital on 100 children aged between 2 months to 14 years with urinary symptoms, recurrent unexplained fever, or abdominal pain. All Participants provided two urine samples for the calcium-to-creatinine ratio measured. Venous blood samples were collected to analyze creatinine, urea, uric acid, calcium, sodium, and potassium.
Results: The prevalence of idiopathic hypercalciuria in children was 20 % at a cutoff point of 0.14 mg/mg ca/ creatinine ratio. Serum ca, creatinine, urine ca excretion, and Ca/creatinine ratio was significantly higher in idiopathic hypercalciuria children than in those with normal ratios but lower urinary creatinine. The Ca/creatinine ratio showed a significant negative correlation with age and urine creatinine, while a positive correlation with serum ca and urinary ca excretion. According to multiple linear regression, serum calcium is a significant predictor for ca/creatinine ratio change in those with idiopathic hypercalciuria.
Conclusion: Hypercalciuria may present different symptoms associated with urinary symptoms, recurrent unexplained fever, and abdominal pain. Therefore, checking the urinary calcium level in children with urinary symptoms with no definite etiology is recommended.