ESPE Abstracts

Background: Some studies suggested a correlation between vitamin D (VD) and the GH-IGF1 but few studies, and with controversial results, have prospectively analysed the vitamin D status in children before and after GH treatment.

Objective and hypothesis: To assess VD status in pre-pubertal children with idiopathic GH deficiency (GHD); and to evaluate effect of GHD and GH treatment on VD levels.

Methods: 50 pre-pubertal children with isolated idiopathic GHD were subjected to history, anthropometric assessment and measurement of 25 hydroxy vitamin D (25-OHD), serum calcium, phosphorous, alkaline phosphatase and parathyroid hormone at diagnosis and 1 year after GH therapy (0.025 mg/kg per day). Patients were compared to 50 age-, sex-, and pubertal stage-matched controls. VD deficiency was defined as a 25-OHD<20 ng/ml, VD insufficiency as a 25-OHD between 20 and 30 ng/ml and VD sufficiency as a 25-OHD > 30 ng/ml.

Results: 25-OHD levels were lower in cases than controls. Twenty GHD children (40%) were VD insufficient and 22 (44%) deficient; while 8 (16%) were VD sufficient at baseline. There was a positive correlation between 25OH-D and baseline GH levels (r=+0.98, P<0.0001). After 12 months of GH therapy, 25OH-D increased (23.4±12.4 ng/ml at baseline vs 34.5±10.1 ng/ml after therapy; P=0.001). Overall, 13 (26%) of children remained insufficient and 11 (22%) deficient, with an increase in prevalence of children with normal levels (26 (52%); P=0.001).

Conclusions: Hypovitaminosis D is prevalent in GHD children and significantly improved 12 months after GH therapy. VD should be assessed in GHD children both at diagnosis and during the follow-up. The relatively high prevalence of low VD levels remaining after 12 months of GH treatment, would suggest the idea that GHD children could also profit from VD supplementation.