Intermittent calcitriol therapy and growth in children with chronic renal failure.

Intermittent calcitriol (1,25D) therapy has been used for the management of secondary hyperparathyroidism in children with chronic renal failure; however, the development of adynamic bone has been demonstrated in up to 40% of pediatric patients after 12 months of intermittent 1,25D therapy. To assess its effect on linear growth, we compared growth and biochemical data from 16 prepubertal patients with biopsy-proven secondary hyperparathyroidism during 12 months of intermittent 1,25D therapy and the preceding year of daily 1,25D therapy. While Z-scores for height remained stable during daily therapy, values decreased from -1.8 +/- 0.32 to -2.0 +/- 0.33, p < 0.01, during intermittent 1,25D therapy; the largest reductions were seen in those who developed adynamic bone. Reductions in growth may be due to the direct inhibitory effects of large intermittent doses of calcitriol on chondrocyte activity.