BONE MINERAL DENSITY IN CHILDREN WITH IDIOPATHIC HYPERCALCIURIA.

UNLABELLED: The aim of the study was to evaluate bone mineral density (BMD) in the lumbar spine in children with idiopathic hypercalciuria. PATIENTS AND METHODS: The study group included 31 children (14 boys, 17 girls) aged 5 to 17 years (mean age 9.8 ± 4.0 years) with idiopathic hypercalciuria. All children remained on normal calcium diet, without vitamin D and citrate supplementation. We evaluated lumbar spine (L1-L4) BMD (L1-L4 BMD) (expressed as Z-score) and blood serum levels of 25-hydroxyvitamin D3 (250HD3), calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and intact parathormone (iPTH). We also evaluated 24-hour urinary Ca, P, and sodium (Na) excretion. RESULTS: Reduced L1-L4 BMD Z-score <-1 was found in 25.8% of children, Z-score values from -1 to 1 in 64.5% of children, and Z-score > 1 in 9.7% of children. Reduced 250HD3 level (< 20 ng/mL) was found in 71% of children, levels in the range of 20-30 ng/mL in 22.6% of children, and levels > 30 ng/mL in 6.4% of children. Seven out of 8 children with L1-L4 BMD Z-score <-1 were found to have 250HD3 deficiency (level < 20 ng/mL). Among children with reduced lumbar spine BMD, most were girls at the mean age of 13.8 years. Ca and P levels were normal in all children. We did not find significant differences in 25OHD3, Ca, and P levels in relation to gender and age. We found a positive correlation between L1-L4 BMD Z-score and serum 250HD3 level. Concomitant nephrolithiasis was found in 50% of patients with reduced lumbar spine BMD. CONCLUSIONS: Reduced lumbar spine BMD in patients with idiopathic hypercalciuria seems to be related to vitamin D3 deficiency.