Somatomedin C in pediatric pathophysiology.

Human beings have essentially two peptides with somatomedinic effect: insulin-like growth factor I (IGF I), somatomedin C (SmC) and IGF II. IGF II does not seem to play a significant role in postnatal growth. IGF I/SmC assay has been used in an attempt to identify GH-deficient subjects. A significant overlap in IGF I/SmC values between subjects with GH deficiency and normal children does not permit screening of pituitary patients. In addition to GH deficiency, low SmC values have been found in some short children with normal GH release to pharmacologic tests. It has been hypothesized that insufficient GH release in these subjects is not detected by the traditional tests. Replacement therapy has been suggested but the results are indefinite. IGF I/SmC assay is highly useful in the diagnosis and monitoring treatment for acromegaly.