PROLONGED ORAL TREATMENT WITH MK-677, A NOVEL GROWTH-HORMONE SECRETAGOGUE, IMPROVES SLEEP QUALITY IN MAN

Previous studies have indicated the existence of common mechanisms reg ulating sleep and somatotropic activity. In the present study, we inve stigated the effects of prolonged treatment with a novel, orally activ e, growth hormone secretagogue (MK-677) on sleep quality in healthy yo ung and older adults. Eight young subjects (18-30 years) followed a do uble-blind, placebo-controlled, three-period crossover design. Each su bject participated in three 7-day treatment periods (with bedtime drug administration), presented in random (Latin square) order, and separa ted by at least 14 days. Doses were 5 and 25 mg MK-677 and matching pl acebo. Six older subjects, ages 65-71 years, each participated in two 14-day treatment periods (with bedtime drug administration) separated by a 14-day washout. Doses were 2 and 25 mg MK-677 during the first an d second periods, respectively. Baseline sleep and hormonal data were obtained on the 2 days preceding the beginning of the first 14-day tre atment period. In young subjects, high-dose MK-677 treatment resulted in an approximately 50% increase in the duration of stage IV and in a more than 20% increase in REM sleep as compared to placebo (p < 0.05). The frequency of deviations from normal sleep decreased from 42% unde r placebo to 8% under high-dose MK-677 (p < 0.03). In older adults, tr eatment with MK-677 was associated with a nearly 50% increase in REM s leep (p < 0.05) and a decrease in REM latency (p < 0.02). The frequenc y of deviations from normal sleep also decreased (p < 0.02). The prese nt findings suggest that MK-677 may simultaneously improve sleep quali ty and correct the relative hyposomato-tropism of senescence.