Serum somatomedin A in growth retarded children.

The levels of serum somatomedin A were determined in 59 growth retarded Japanese children by a radioreceptor assay. Low levels were found in 10 children with growth hormone (GH) deficiency and 7 children with relative GH deficiency with means of 0.26 +/- 0.48 +/- 0.04 U/ml, respectively. Serum somatomedin A levels in 42 retarded children with normal growth hormone levels were within the range of normal adults, and did not correlate with degree of short stature. Significant increases of somatomedin A after hGH administration were found in children with growth hormone deficiency but not in children with normal growth hormone. These results show that determination of somatomedin A in serum corelates well with the state of growth hormone secretion, and is of great importance in the selection of patients for treatment with human growth hormone.