Mean 24-hour growth hormone and testosterone concentrations in relation to pubertal growth spurt in boys with normal or delayed puberty.

The mean growth hormone concentration during 24-hour period in 7 boys of short familial stature and a growth rate of 3.2-5.4 cm/year was between 1.0 and 4.6 ng/ml serum. In 7 boys with pubertal growth spurt and familial tallness (growth rate 7.2-11.0 cm/year) it varied from 0.97 to 4.4 ng/ml and in 6 boys with constitutional delay of puberty (a growth rate of 4.2-5.2 cm/year prior to puberty) from 1.3 to 4.3 ng/ml. No correlation was found between the 24-hour mean growth hormone concentration and the mean 24-hour testosterone concentration in serum or the growth rate, but a correlation was found between testosterone and the growth rate. It is concluded that the growth spurt in puberty is not due to a change in growth hormone concentration but rather to the increase of androgen production in puberty.