Abstract
Plasma Human Growth Hormone (HGH) levels were determined in 176 healthy school children, 74 monozygotic and 14 dizygotic twins of 13-to 18-year-old, and in 34 healthy adult subjects 4 hrs. after the test breakfast. There was a considerable variation in plasma HGH concentrations, but most samples showed the values of 0.25mμg/ml to 40mμg/ml. The wide distribution of plasma HGH was especially noted in 13-and 14-year-old subjects in both sexes. In the male subjects, a definite difference in the distribution was noted between the 13-to 14-year-old school children and the 16-year-old or older subjects. In the female subjects, the difference was not so noticeable as in the male subjects. No correlation was noted between the plasma HGH levels and physical size of the subjects, nor between the values of plasma HGH in individual twins.
