Sleep-wake patterns of LH and testosterone release in prepubertal boys.

Ten prepubertal boys who ranged in age from 6 11/12 to 14 2/12 years were studied for 2 consecutive nights. The subjects went to sleep at their usual times and sleep patterns were monitered polygraphically. Each night blood samples were drawn every 30 min from 1800 to 0600 h and plasma LH and testosterone (T) levels were measured on each sample. During evening wakefulness the mean LH (range 2.8-5.1 mIU/ml) and T (range 31-116 pg/ml) levels were in the normal prepubertal range for each subject. In the 5 youngest subjects (age 6 11/12 to 10 8/12 years) the mean hormone levels during sleep were significantly higher than the wakeful levels in 2 of 9 and 0 of 9 study nights for LH and T, respectively. In contrast, in the older prepubertal boys (age 13 2/12 to 14 2/12 years) the mean levels during sleep were significantly higher than wakeful values during 8 of 9 and 5 of 9 study nights for the same respective hormones. These data suggest that in young prepubertal subjects the sleep related rises of LH and T are either absent or not discernible in the peripheral blood. The prepubertal pattern of sleep-entrained LH and T release may be seen in prepubertal boys approaching the time of puberty and these hormonal rhythms are antecedent to the physical changes of puberty.