Serum IGF-I and IGFBP-3 in 919 Healthy Korean Children and Adolescents: Normal Values and Correlations with Age, Sex, Height, Body Mass Index and Bone Age

Song, Ae Kyung; Kim, Hee Joon; Suk, Hyo Jung; Hwang, Jin Soon; Hong, Chang Ho

Abstract

PURPOSE
IGF-I and IGFBP-3 are usually used for the diagnosis of growth hormone deficiency. Until now we don't have normal values of IGF-I and IGFBP-3 in Korea. Therefore, we evaluated the normal values of IGF-I and IGFBP-3 in healthy Korean children and adolescents and compared with reference values in Pediatric endocrinology which was published by the Korean society of pediatric endocrinology. We also evaluated correlation of age, sex, height, body mass index and bone age with serum IGF-I and IGFBP-3 levels.
METHODS
We studied the serum levels of IGF-I and IGFBP-3 in 919 and 686 normal healthy children and adolescents respectively who were examined for the growth evaluation at the department of Pediatrics, Ajou University Hospital from January, 1994 to September, 2004. IGF-I and IGFBP-3 were measured using IRMA method.
RESULTS
Serum levels of IGF-I and IGFBP-3 were increased with age from early childhood into adolescence. Serum IGF-I correlated significantly with age, sex and BMI but serum IGFBP-3 correlated significantly only with age and sex (P<0.05). IGF-I levels in our data were lower than reference values in Pediatric Endocrinology during early childhood but were higher in puberty. IGFBP-3 levels were higher throughout childhood and puberty.
CONCLUSION
There was a significant difference between our data and reference values which were evaluated in U.S.A., so longitudinal antegrade large scale study must be undertaken to obtain the normal reference range of healthy Korean children and adolescents. We believe that one should take into account the patient's age, sex, height, BMI and bone age when measuring serum IGF-I and IGFBP-3 levels for the evaluation of short stature.