Diurnal administration of human growth hormone-releasing factor does not modify sleep and sleep-related growth hormone secretion in normal young men

Abstract

hGRF (iv 50 \ g=m\ g) was administered to 6 normal young adult males at 09.00 and 20.00 h on different days. Nocturnal GH secretion was monitored during polygraphic sleep recordings on both control nights and nights following hGRF administration. Sleep-related GH secretion and sleep parameters were not affected by diurnal hGRF administration.The close association in adult man between the occurrence of the initial episode of slow-wave sleep (SWS) and the highest peak of plasma GH concen¬ tration in a 24-h period led to the concept of sleep-related GH secretion (Takahashi et al. 1968; Sassin et al. 1969), submitted to control mecha¬ nisms probably different from those involved in day-time secretion and in pharmacologically indu¬ ced secretion (Mendelson et al. 1979). It has been reported that in man administration of GH subsequently can blunt the secretory re¬ sponse to pharmacological stimulation of GH secretion (Hagen et al. 1972) as well as sleeprelated GH secretion (Mendelson et al. 1983). This negative feedback appears, then, to be exerted at some common point of the pathways involved in the secretory mechanisms. Administration of GH in animals (Stern et al. 1975 ; Drucker-Collin et al. 1975 ; Stern & Morgane 1977) results in some changes in sleep stages with increased REM sleep and decreased SWS. In man, acute administration of GH (5 U) is followed by a decrease in SWS and an increment in REM sleep (Mendelson et al. 1980; Mendelson 1982), whereas iterative administration has no significant effect on sleep (Mendelson et al. 1983).Synthetic human growth hormone-releasing fac¬ tor (hGRF) powerfully stimulates GH release in normal young adult men (Thorner et al. 1983;Rosenthal et al. 1983;Gelato et al. 1984;Sassolas et al. 1984). This study was undertaken in order to determine whether a GH-rise, induced during day¬ time by hGRF administration, would exert an effect on the sleep-related GH secretion and on sleep stages. Materials and MethodsSix normal young men (22-26 years of age) taking no medication, within 10% of their ideal body weights, were enrolled for this study. They had given written informed consent. Protocol had been approved by our institutional Ethics Committee.The subjects were admitted to the Centre de Médecine Nucléaire (Lyon) for two trial periods at intervals of 1 week. The first period included a first control night

Growth Hormone-Deficient Young Adults Have Decreased Deep Sleep

“…Animal and human studies have yielded contradictory results. In some no change in sleep occurred after administration of GH [13], in others an increase in total REM sleep time was observed [15][16]. The implication of a reduced REM sleep time in our patients is not fully understood, but REM sleep has been attri buted a facilitating role in the process of memory [17,18].…”

Effects of Growth Hormone-Releasing Hormone and Somatostatin on Sleep EEG and Nocturnal Hormone Secretion in Male Controls

“…Sleep, GH and Cortisol under GHRH and SRIF neuropeptide to animals [9][10][11] but contradicts studies in which GHRH was administered as a single intravenous injection to human controls [13,14].…”

“…In this context the somatotrophic system, which is stimulated by GH-releasing hormone (GHRH) [7] and suppressed by somatostatin (SRIF) [8], is of particular interest. Non-REM sleep [9,10], and particu larly SWS [11], increased after intraventricular injection of GHRH in rats [9][10][11] and in rabbits [9], These find ings led to the suggestion that both GH secretion and SWS are stimulated by GHRH [12], Recently Garry et al [13] and Kupfer et al [14] tested this hypothesis in men but failed to find a significant effect upon the sleep EEG after injection of a single bolus of GHRH. Con flicting data exist on the sleep EEG effects of SRIF.…”

The Influence of Growth Hormone on Sleep in Adults With Growth Hormone Deficiency

“…In normal subjects it caused a decrease in delta sleep and an increase in REM sleep (Mendelson et al, 1980). G R F caused no significant change in any sleep parameter (Garry et al, 1985). Studies on sleep after treatment with G H in growth hormone deficiency has been carried out only in children after short-term administration showing a decrease in stage 3 sleep, but no change in REM sleep (Wu & Thorpy, 1988).…”