Alteration of Serum Insulin-like Growth Factor(IGF)-I and IGF-Binding Protein-2 in Healthy Population with Aging / 대한소아내분비학회지

ABSTRACT

PURPOSE:Insulin-like growth factors, IGF- I and IGF-II, are proteins that promote cellular growth and differentiation of the various organs including the kidney. These peptides circulate in serum bound to specific carrier proteins, called IGF binding proteins(IGFBPs). The IGFs are produced in most organs but liver is believed to be the principal source of circulating IGF-I. We studied the correlation of serum IGF-I and IGFBP-2 pattern with aging. METHODS:Sera were collected from 320 healthy population who were grouped according to age. IGF-I was seperated from IGFBPs by Sephadex G-50 acid chromatography. We measured serum IGF-I and IGFBP-2 by using radioimmuno-assay (RIA) and immunoradiometric assay (IRMA) respectively. RESULTS:Serum IGF-I levels were quite low in early childhood, rising slowly and reaching a peak during puberty and a significant decline(P<00.01) during adulthood. The age-dependent pattern of serum IGFBP-2 levels shows a pattern opposite to that of IGF-I which are high at birth, decline by late puberty and increase again with aging. CONCLUSION: Our results demonstrate the alteration of serum IGF-I and IGFBP- 2 pattern with aging. These data suggests that when these tests are performed in the clinic, their interpretation should be based upon age specific criteria.