Simultaneous stimulation of slow-wave sleep and growth hormone secretion by gamma-hydroxybutyrate in normal young Men.

Abstract

The aim of this study was to investigate, in normal young men, whether gamma-hydroxybutyrate (GHB), a reliable stimulant of slow-wave (SW) sleep in normal subjects, would simultaneously enhance sleep related growth hormone (GH) secretion. Eight healthy young men participated each in four experiments involving bedtime oral administration of placebo, 2.5, 3.0, and 3.5 g of GHB. Polygraphic sleep recordings were performed every night, and blood samples were obtained at 15-min intervals from 2000 to 0800. GHB effects were mainly observed during the first 2 h after sleep onset. There was a doubling of GH secretion, resulting from an increase of the amplitude and the duration of the first GH pulse after sleep onset. This stimulation of GH secretion was significantly correlated to a simultaneous increase in the amount of sleep stage IV. Abrupt but transient elevations of prolactin and cortisol were also observed, but did not appear to be associated with the concomitant stimulation of SW sleep. Thyrotropin and melatonin profiles were not altered by GHB administration. These data suggest that pharmacological agents that reliably stimulate SW sleep, such as GHB, may represent a novel class of powerful GH secretagogues. ( J. Clin. Invest. 1997. 100:745-753.)

Increases in Serum Growth Hormone Concentrations Associated with GHB Administration

“…The increases published here for this small GHB dose are around 15 % of that seen from a 0.15 U/kg subcutaneous dose of somatropin (29). Given that the work of Van Cauter suggests 16 that larger doses will be capable of producing an even greater response, the potential for GHB abuse in sport is noteworthy (25). Though current research in this area is limited, the long term administration of GHB to alcoholics did not affect muscle mass or waist to hip ratio, but this may be a consequence of the GH release associated with GHB administration being suppressed in alcoholics (30).…”

“…These doses are equivalent to approximately 35 mg/kg, 42 mg/kg and 50 mg/kg respectively, and therefore are all in excess of the dose administered in this study (25).…”

“…Van Cauter et al focused on the ability of GHB to augment the natural increase in GH serum concentrations associated with the onset of slow wave sleep (25). Eight healthy male volunteers were given doses of 2.5 g, 3.0 g or 3.5 g at 22:45 h prior to a "bedtime" of 23:00 h. Basal serum concentrations were typically less than 10 ng/mL prior to sleep, while GH C max associated with the onset of sleep in the control group was around 20 ng/mL.…”

“…The ability of GHB to stimulate GH production in the absence of sleep in both male and female volunteers was investigated as part of a GHB administration study.Twelve healthy volunteers (6 men and 6 women) were given a small oral dose (25 mg/kg) of GHB (as Xyrem®) at 10:00 h. Basal blood samples (as serum) were taken 10 min prior to GHB administration, with additional samples taken at 10,15,20,25,30, 45, 60, 90, 120, 150, 180, 240, 360 and 480 min post-administration. The serum concentrations of GHB were measured by GC-MS and GH by immunometric assay.…”

Hyperglycaemia and ketosis induced by gamma hydroxybutyrate (GHB)

“…Why does this occur? It has been well documented that GHB can stimulate growth hormone and ACTH and cortisol release, which will induce resistance to the action of insulin [3]. It has also been shown that recreational use of GHB, presumably in high doses, can result in pseudoCushing's syndrome [4].…”