ESPE Abstracts

Background: According to the latest studies vitamin D has an effect on the production and/or secretion of IGF1 in the liver, but the exact mechanism regulating these relationships has not been thoroughly explained.

Objective and hypotheses: Evaluation of the relationship between 25(OH)D and IGF1 levels in the serum of children with GH deficiency (GHD).

Method: The study group consisted of 76 GH deficient children qualified for GH therapy. The GHD was defined as GH secretion in stimulatory tests below 10 ng/ml. 25(OH)D and IGF1 concentrations were evaluated before the start of GH treatment. The study group was divided into two subgroups, depending on the concentration of 25(OH)D: deficient children in need of treatment (25(OH)D < 20 ng/ml; n=33) and non-deficient children (25(OH)D > 20 ng/ml; n=43). The two subgroups did not differ significantly in terms of GH deficiency defined as the maximum secretion of GH in tests. IGF1 concentration was expressed as an S.D. normalized for bone age.

Results: It was only in the group of children with 25(OH)D deficiency that a weak positive correlation between 25(OH)D concentration and IGF1 concentration was found (P<0.05). There was no significant correlation between the concentrations of 25(OH)D and IGF1 in the group without vitamin D deficiency or in the whole study group.

Conclusion: The results suggest that low serum 25(OH)D concentrations can influence IGF1 concentrations. Therefore, in vitamin D deficient patients their vitamin D status should be normalized before their IGF1 concentrations are evaluated.