Greater efficacy of episodic than continuous growth hormone-releasing hormone (GHRH) administration in promoting slow-wave sleep (SWS).
Level 2 - randomized trial
Controlled clinical trial comparing administration regimens in healthy humans
PubMed 8772566 · doi:10.1210/jcem.81.3.8772566
What was done
Healthy volunteers received 200 µg growth hormone-releasing hormone (GHRH) intravenously across three conditions: episodic administration (four 50 µg boluses at 22:00, 23:00, 24:00, and 01:00), continuous infusion (57 µg/h between 21:30 and 01:00), and placebo. Nocturnal sleep architecture and plasma GH concentrations were evaluated across conditions.
What was found
Time spent in stage 4 slow-wave sleep (SWS) was significantly greater during episodic GHRH administration than continuous infusion (P < 0.01). Compared to placebo, episodic GHRH increased total SWS (P < 0.01) and rapid eye movement (REM) sleep (P < 0.05), while reducing time spent awake and in stage 1 sleep (P < 0.05). Continuous infusion had no significant effects on sleep stages compared with placebo. Both regimens increased plasma GH concentrations over placebo (P < 0.01), with episodic administration yielding a slightly larger elevation than continuous infusion (P < 0.05). Exact durations, percentages, and hormone concentrations were not provided in the abstract.
Why it matters
This study shows that the kinetics of GHRH delivery determine its somnogenic effects, with pulsatile administration matching physiological release and effectively promoting deep sleep.
Limits
The abstract does not state the sample size, participant demographics (such as sex and age range), or whether treatments were randomized or blinded. Specific numerical values for sleep stage durations and plasma GH levels are omitted.
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