Disordered growth hormone and prolactin secretion in primary disorders of sleep.

Growth hormone (GH) and prolactin (PR) secretion were evaluated in 28 patients who had sleep apnea or narcolepsy but no other primary neurologic or endocrine disorders. Eighty-one percent of subjects with impaired alertness failed to demonstrate serum GH concentrations in excess of 5 ng per milliliter following oral administration of L-DOPA, 500 mg. Diminished GH responses to sleep and intravenous arginine were observed in 57 percent and 44 percent, respectively, of patients tested. Sleep-related PRL release was less than normal in women with narcolepsy, with or without sleep apnea. All patients had at least one abnormality in GH or PRL secretion.