Serum IGF-I and IGFBP-3 levels by immunoeadiometric assay (IRMA) in diagnosis of growth hormone deficiency.

The anabolic actions of growth hormone (GH) are mediated by insulin-like growth factor-I (IGF-I) which circulates in blood bound with high affinity to specific carrier proteins, IGF-binding proteins (IGFBP) especially IGFBP-3. Serum levels of IGF-I and IGFBP-3 reflect 24-hour growth hormone status. We divided 44 children into 4 groups depending on growth hormone status. Group I (n=9), complete growth hormone deficiency (GHD). Group II (n=9), partial GHD. Group III (n=12), idiopathic short stature Group IV (n=14), normal children. Measurement of serum IGF-I and IGFBP-3 was performed by immunoradiometric assay (IRMA). The results showed the serum IGF-I and IGFBP-3 levels in group I were 123.1 + 106.8 ng/ml and 1825.1+ 966.6 ng/ml respectively which were significantly different from the levels in group 4, IGFI=270.7+ 139.4 ng/ml (p=0.025) IGFBP-3 = 2702.7+ 500.4 ng/ml (p=0.009) but not in group 2 and 3. In conclusion serum IGF-I and IGFBP-3 levels were proved to by useful for diagnosis of complete GHD.