Sleep: The Linchpin of Hormone Regulation? A Literature Review

Healthy sleep can modulate hormone levels which affect an individual's overall health. The quality and quantity of a person's sleep are important indicators of the changes in hormone levels in the body and of the severity of an individual's non-transmittable chronic health conditions, moods, energy level, and disease processes. Several hormone levels that are known to fluctuate during sleep include: insulin, leptin, ghrelin, testosterone, progesterone, cortisol, melatonin, and serotonin. An evaluation of how sleep stabilizes the body's multiple hormone levels reveals the importance of sleep; these hormone levels depend on high quality and quantity sleep to keep an individual healthy. A review of the literature reveals how sleep is the driving regulator of all of the body's hormone levels. Sleep efficiency is also an indicator of high quality sleep. The literature review resulted from a search of databases that included: PubMed, EBSCOhost, Access Medicine, Medscape, and DynaMed using key words: sleep, sleep hygiene, sleep efficiency, sleep quality index, sleep and each hormone listed (insulin, leptin, ghrelin, testosterone, progesterone, cortisol, melatonin, and serotonin). The total number of articles included in this review is 38; after evaluating the abstracts and full text of 124 articles, 67 were excluded for being similar and 19 were eliminated as not relevant. Future research into other hormones altered by sleep loss should include: cholecystokinin, glucagonlike peptide-1 (GLP-1), peptide YY, orexin, neuropeptide Y, adipokines, dopamine and thyrotropin.