464 TESTOSTERONE (T) BUT NOT OXANDROLONE (OX) INCREASES SPONTANEOUS GROWTH HORMONE (GH) AND SOMATOMEDIN-C (SmC) CONCENTRATIONS IN BOYS WITH CONSTITUTIONAL DELAY OF GROWTH AND ADOLESCENCE (CDGA)

Abstract

The effect of T and OX on GH and SmC concentrations was studied in boys with CDGA. Ten boys received OX (0.1 mg/kg/d) for 65±5 d and 5 boys received T propionate (7.5 mg IM × 7 d) followed by T enanthate (100 mg IM q mo for 3 mo). Serum GH was measured in samples obtained q 20 min for 24 hr before and 65±5 d into therapy. SmC levels were measured twice during the same 24 hr period before and 65±5 d into therapy. The 24 hr integrated concentration of GH (ICGH) was obtained from the mean of 72 samples and compared to that obtained from a pooled sample (p=NS). A pulse of GH was recorded if the peak level rose >5 ng/ml. We found no differences in the ICGH, in the number of GH secretory episodes, or in the SmC levels in boys treated with OX. However, in boys treated with T there were significant increases in the ICGH, the number of GH secretory episodes and in the SmC levels.We conclude that testerone therapy doubles the amount of GH secreted daily, although OX at 0.1 mg/kg/d is without effect. This increase in GH secretion may contribute to the increased growth rate at puberty.