The newer clinical utilities of the measurement of insulin like growth factor-I (IGF-I)

Serum insulin-like growth factor-I (IGF-I) measured by newly developed ELISA with monoclonal antibody (27 E 10) which recognizes the epitope on the c-chain of IGF-I. Total IGF-I (tIGF-I) values were obtained from serum after acid-ethanol treatment. Direct IGF-I (dIGF-I) values were obtained directly from serum before treatment. Indirect IGF-I (iIGF-I) values were caliculated by subtracting dIGF-I from tIGF-I. Each IGF-I values in the serum samples from the patients with Diabetes Mellitus (DM), Osteoporosis were compared with those from the control samples. In the mean value of dIGF-I, female control were higher than male control, DM were higher than control in both gender, and female DM were higher than male DM. In the mean values of tIGF-I, statistical significance was shown only in comparing female DM with female control. No statistical significance was detected among the values of iIGF-I. Above data suggest that the dIGF-I are more valuable than tIGF-I in clinical use. We conclude that the measurement of IGF-I become more useful with increasing utility of recombinant IGF-I, and the further investigations about the sense of dIGF-I are needed.