Sleep Related Human Growth Hormone (GH) Release: A Test of Physiologic Growth Hormone Secretion in Children

Abstract

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 single blood sample drawn approximately 90 minutes after sleep onset serves as a good index of GH secretion in children and may provide a screening test to rule out GH deficiency.