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Sleep-wake patterns of LH and testosterone release in prepubertal boys
Insights
Sleep-related rises in luteinizing hormone (LH) and testosterone (T) are not evident in young boys but emerge as puberty nears. These hormonal changes precede physical pubertal development.
Area of Science:
- Pediatric endocrinology
- Sleep medicine
- Reproductive biology
Background:
- Prepubertal hormonal profiles are critical for understanding pubertal onset.
- Sleep-wake cycles influence various physiological processes, including hormone release.
Purpose of the Study:
- To investigate sleep-related changes in luteinizing hormone (LH) and testosterone (T) levels in prepubertal boys.
- To determine if hormonal rhythms associated with puberty are present before physical changes manifest.
Main Methods:
- Polygraphic sleep monitoring in ten prepubertal boys (ages 6-14) over two nights.
- Frequent blood sampling (every 30 min from 1800 to 0600 h) to measure plasma LH and T levels.
- Comparison of hormone levels during sleep versus wakefulness.
Main Results:
- Younger prepubertal boys (6-10 years) showed no significant sleep-related increases in LH or T.
- Older prepubertal boys (13-14 years) exhibited significant sleep-related elevations in LH and T during most study nights.
- Hormonal patterns suggest sleep-entrained release of LH and T emerges before puberty.
Conclusions:
- Sleep-related surges of LH and T are absent or undetectable in younger prepubertal boys.
- The development of sleep-entrained LH and T release patterns in prepubertal boys indicates an antecedent hormonal shift towards puberty.
- These findings highlight hormonal rhythms as precursors to the physical transformations of puberty.
Abstract:
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.