Study: Puberty Turned On by Brain During Deep Sleep

A new study shows the importance of deep sleep to puberty in children.

Slow-wave sleep, or 'deep sleep', is intimately involved in the complex control of the onset of puberty, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology and Metabolism (JCEM).

The many changes that occur in boys and girls during puberty are triggered by changes in the brain. Previous studies have shown that the parts of the brain that control puberty first become active during sleep, but the present study shows that it is deep sleep, rather than sleep in general, that is associated with this activity.

"If the parts of the brain that activate the reproductive system depend on deep sleep, then we need to be concerned that inadequate or disturbed sleep in children and young adolescents may interfere with normal pubertal maturation," said Harvard researcher, Natalie Shaw, MD, of Massachusetts General Hospital and Boston Children's Hospital who led the study. "This is particularly true for children who have been diagnosed with sleep disorders, but may also have more widespread implications as recent studies have found that most adolescents get less sleep than they require."

In the study, researchers examined pulses of luteinizing hormone (LH) secretion in relation to specific sleep stages in children ages 9-15. LH is essential for reproduction and triggers ovulation in females and stimulates the production of testosterone in males. Researchers found that the majority of LH pulses that occur after sleep are preceded by deep sleep suggesting that deep sleep is intimately involved in pubertal onset.

Other Harvard researchers participating in the study included James Butler of Brigham & Women's Hospital; and Scott McKinney, Susan Nelson, Jeffery Ellenbogen and senior author Janet Hall, all of Massachusetts General Hospital.

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Study Shows A Lack of Sleep May Affect When Kids Enter Puberty

A new study claims that the amount of deep sleep a child gets may help determine when they enter puberty.

Getting enough deep sleep may play an important role in determining when puberty begins.

In a small new study, adolescents ages 10 to 15 were examined while they slept for increases in luteinizing hormone, which triggers ovulation in females and stimulates the production of testosterone in males.

Previous research showed that luteinizing hormone levels increase dramatically before puberty, and that this increase occurs initially only at night. The new study found that most of the surges occurred during slow-wave sleep, or deep sleep, from which it is particularly hard to wake people up.

The findings "raise concerns that the disordered or restricted sleep that is increasingly prevalent in the adolescent population may compromise normal pubertal development," the researchers said.

Because the study, conducted at Massachusetts General Hospital in Boston, involved only nine participants, the researchers noted that more work would be needed to confirm the results.

The participants spent a night sleeping in a laboratory, and blood samples were collected through a catheter every 10 minutes. The blood samples were analyzed for levels of luteinizing hormone.

Participants experienced an average of four to six surges of luteinizing hormone during the night. Fifty-two percent of these surges began during deep sleep, the researchers said.

Participants initially had been recruited for a study on obstructive sleep apnea, but during the sleep study, they did not meet the criteria for the condition.

The study is to be published in an upcoming issue of theJournal of Clinical Endocrinology and Metabolism.

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