Sleep-promoting effects of growth hormone-releasing hormone in normal men.
Level 3 - non-randomized controlled study
Interventional physiological study in humans without explicit reporting of randomization or control procedures in the abstract.
PubMed 8476038 · doi:10.1152/ajpendo.1993.264.4.E594
What was done
Healthy young men received intravenous bolus injections of growth hormone-releasing hormone (GHRH, 0.3 µg/kg body weight) across three conditions: during early sleep (first slow-wave sleep period), during late sleep (third REM sleep period), and during early sleep after sleep deprivation until 04:00. Sleep stages and wakefulness were evaluated.
What was found
Without sleep deprivation, GHRH injection during early sleep did not alter slow-wave sleep but increased REM sleep. GHRH administration in the third REM period resulted in a marked decrease in wakefulness and an almost 10-fold increase in slow-wave sleep. When given during the first slow-wave period after sleep deprivation until 04:00, GHRH reduced wake duration. Exact numerical durations, baseline values, and statistical measures were not reported in the abstract.
Why it matters
This study provides early direct human evidence that exogenous GHRH has sleep-promoting effects, particularly during periods of low homeostatic sleep propensity.
Limits
The abstract does not state the sample size, whether a placebo control or randomization was used, or specific numerical values and statistical variance. The population was limited to healthy young men, limiting generalizability to women and clinical populations.
Cited by
- contradicts Growth hormone secretagogues such as tesamorelin and sermorelin increase slow-wave deep sleep but reduce REM sleep.