Increases in Serum Growth Hormone Concentrations Associated with GHB Administration

Abstract

The administration of gamma-hydroxybutyrate (GHB) has been reported to augment the increase in growth hormone (GH) secretion associated with the onset of sleep. 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.Following GHB administration, volunteers exhibited effects consistent with mild sedation, i.e. relaxed with normal responses to verbal stimuli. Despite none being asleep, an increase in serum GH concentration occurred in 11 out of the 12 volunteers (5 women and 6 men). In these volunteers, peak GH concentrations occurred 45 -60 min post-administration compared to a mean serum t max for GHB of 23 min (sd = 5.4 min). The absolute increase in GH was similar for the men and women, averaging 3.4 ng/mL and 3.7 ng/mL respectively. The mean intra-individual increase in GH was much greater in males (29 times) compared with females (2 times), as males had (as expected) lower basal GH concentrations (mean = 0.26 ng/mL) compared to females (mean = 5.4 ng/mL). After maximising, the GH C max decreased rapidly (in agreement with GHB concentrations), returning to basal concentrations at around 90 -120 min post-administration. GHB administration at low therapeutic concentrations results in increases in serum GH concentrations in healthy male and female volunteers in the absence of sleep onset.3

Interpreting γ-hydroxybutyrate concentrations for clinical and forensic purposes

“…Earlier GHB was investigated as a possible general anesthetic [3,4], but was rejected for clinical purposes owing to its lack of an analgesic effect and the fact that some patients vomited after treatment [5]. Shortly afterward, GHB could be purchased from health food stores and was touted as a dietary supplement for use by body builders to stimulate the growth hormone and increase muscle mass (anabolic effect) [6,7].…”

GHB receptors - a new trend in psychopharmacology?

“…Given the reports cited above, it is possible that the increase in GH observed after GHB administration is a consequence of an increase in glutamatergic transmission resulting from the activation of GHBR. A study conducted in 2016 in a group of twelve volunteers also demonstrated that GHB increased the release of GH [31]. The difference in the results may be explained by differences in GHB administration and the related differences in the bioavailability and metabolism of the agent.…”

“…The difference in the results may be explained by differences in GHB administration and the related differences in the bioavailability and metabolism of the agent. In the case of experiments involving human volunteers, GHB was administered orally [31], while in the case of animals, the agent was administered subcutaneously [27]. Subcutaneous administration may have resulted in higher blood GHB concentrations compared to oral administration.…”

“…Biorąc pod uwagę przytoczone wyżej doniesienia, możliwe jest, że obserwowany po podaniu GHB wzrost GH jest wynikiem wzrostu przekaźnictwa glutaminianergicznego wynikającego z aktywacji GHBR. Przeprowadzone w 2016 badania na grupie 12 ochotników także dowiodły, że GHB zwiększa uwalnianie GH [31]. Możliwym wytłumaczeniem różnicy wyników badań są różnice w podaniu GHB i związane z tym różnice w biodostępności i metabolizmie środka.…”

“…Możliwym wytłumaczeniem różnicy wyników badań są różnice w podaniu GHB i związane z tym różnice w biodostępności i metabolizmie środka. W przypadku doświadczeń przeprowadzonych przy pomocy ochotników GHB było podawane doustnie [31], natomiast w przypadku zwierząt środek podawano podskórnie [27]. W konsekwencji mogło to spowodować wyższe stężenie GHB we krwi niż w przypadku doustnego podania.…”