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.
01 Oct 2015 - 03 Oct 2015