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Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes
Article first published online: 27 MAR 2007
Sleep and Biological Rhythms
Volume 5, Issue 2, pages 126–131, April 2007
How to Cite
YAMADERA, W., INAGAWA, K., CHIBA, S., BANNAI, M., TAKAHASHI, M. and NAKAYAMA, K. (2007), Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms, 5: 126–131. doi: 10.1111/j.1479-8425.2007.00262.x
- Issue published online: 27 MAR 2007
- Article first published online: 27 MAR 2007
- Accepted for publication 22 November 2006.
- amino acid;
- slow wave sleep latency;
- St Mary’s Hospital Sleep Questionnaire;
- Stanford Sleepiness Scale
In human volunteers who have been continuously experiencing unsatisfactory sleep, effects of glycine ingestion (3 g) before bedtime on subjective sleep quality were investigated, and changes in polysomnography (PSG) during sleep were analyzed. Effects on daytime sleepiness and daytime cognitive function were also evaluated. Glycine improved subjective sleep quality and sleep efficacy (sleep time/in-bed time), and shortened PSG latency both to sleep onset and to slow wave sleep without changes in the sleep architecture. Glycine lessened daytime sleepiness and improved performance of memory recognition tasks. Thus, a bolus ingestion of glycine before bedtime seems to produce subjective and objective improvement of the sleep quality in a different way than traditional hypnotic drugs such as benzodiazepines.