[Correlation between growth velocity and hematologic levels of somatomedin C during the treatment with growth hormones (GH) in subjects with "classic" and "non-classic" deficits of GH].

In this study the authors examined 14 subjects with "classic" growth hormone (GH) deficiency and 40 with "non classic" GH deficiency treated with GH for a period of 6-36 months. Height velocity (HV) and plasma Somatomedin C (SmC) levels have been evaluated every 6 months during GH therapy. Both HV and SmC significantly increased (p < 0.001) during GH therapy in comparison to pretreatment values, but without any difference between the two groups; furthermore no significant difference was present among each six-monthly value of SmC. During GH treatment the following correlations resulted between SmC and HV: at time 0, r = 0.494 (p = 0.0004); after 6 months, r = 0.779 (p < 0.0001); after 12 months, r = 0.660 (p = 0.0001); after 18 months, r = 0.657 (p = 0.0001); after 24 months, r = 0.593 (p = 0.0038); after 30 months, r = 0.550 (p = ns); after 36 months, r = 0.465 (p = ns). Furthermore, mean value of SmC (y) correlated with mean value of HV (x) during GH treatment: r = 0.697, p < 0.0001; regression equation: y = 242x + 576. Finally no correlation was present among six-monthly SmC values, including those pre-treatment, and HV values in each of following periods. In conclusion, during GH treatment in subjects with GH deficiency plasma SmC levels correlate with HV, but have not a predictive value of the growth response to GH treatment itself.