The influence of sleep variables on muscle protein anabolism is little studied, but data on the effects of slow-wave sleep and the syndrome of obstructive sleep apnea on the hypothalamic-pituitary axis indicate that interventions in the sleep structure and disorders impact on the age-related muscle loss. Thus, we propose to assess the acute effects of a drug potentially capable of increasing slow wave sleep, and consequently growth hormone release during sleep, on the physiological release of growth hormone, testosterone and IGF-1 during the night in older healthy men.