Sleep-related Growth Hormone Research Articles

Sleep related human growth hormone (GH) release: a test of physiologic growth hormone secretion in children.

Plasma growth hormone (GH) concentration was measured in 46 healthy children ages 3–11 years and four subjects with known GH deficiency at 90 minutes after the onset of sleep and before breakfast the following morning. Thirty-nine of the subjects were hospitalized and seven were sampled in their homes. The mean ± se sleep plasma GH concentration was 17.7 ng/ml ± 1. 4 (range 7.0–48) as compared to a mean pre-breakfast GH concentration of 3.5 ng/ml ± 0.4 (range 0.6–10.0) p < 0.01. The results were comparable in all age groups whether hospitalized or non-hospitalized, and in male and female subjects. In only four children was the sleep-related level less than 10 ng/ml. The sleep levels compared closely with peak plasma GH concentrations observed in response to arginine provocation in 25 normal children (mean 17.6 ± 1.9, range +7.7–40.0). Since sleep-related GH rises occur without artificial stimulation, this test is an index of both the presence and physiologic release of GH by the pituitary. Therefore a sin...

Growth hormone secretion during sleep.

Plasma growth hormone (GH), insulin, cortisol, and glucose were measured during sleep on 38 nights in eight young adults. Blood was drawn from an indwelling catheter at 30-min intervals; EEG and electrooculogram were recorded throughout the night. In seven subjects, a plasma GH peak (13-72 mmug/ml) lasting 1.5-3.5 hr appeared with the onset of deep sleep. Smaller GH peaks (6-14 mmug/ml) occasionally appeared during subsequent deep sleep phases. Peak GH secretion was delayed if the onset of sleep was delayed. Subjects who were awakened for 2-3 hr and allowed to return to sleep exhibited another peak of GH secretion (14-46 mmug/ml). Peak GH secretion was not correlated with changes in plasma glucose, insulin, and cortisol. The effects of 6-CNS-active drugs on sleep-related GH secretion were investigated. Imipramine (50 mg) completely abolished GH peaks in two of four subjects, whereas chlorpromazine (30 mg), phenobarbital (97 mg), diphenylhydantoin (90 mg), chlordiazepoxide (20 mg), and isocarboxazid (30 mg) did not inhibit GH peaks. Altered hypothalamic activity associated with initiation of sleep results in a major peak of growth hormone secretion unrelated to hypoglycemia or changes in cortisol and insulin secretion.