DLMO (Dim Light Melatonin Onset)
DEDLMO (Beginn der Melatoninausschüttung bei gedämpftem Licht)
Dim Light Melatonin Onset (DLMO) is a specific time in the evening. It is when your body's own melatonin, in saliva or plasma, rises above a set threshold. The measurement is done under dim light (typically below 50 lux), because brighter light would suppress melatonin. The standard thresholds are around 3 pg/mL in saliva, or 10 pg/mL in plasma, sampled every 30 minutes. Alfred Lewy and colleagues formalized it. DLMO is widely seen as the gold-standard phase marker of your circadian clock. That is because melatonin is tightly controlled by the suprachiasmatic nucleus, and is barely confounded by sleep, posture, or activity. Clinically, DLMO is used to diagnose delayed and advanced sleep-wake phase disorders (DSPS and ASPS). It also helps time melatonin and light therapy, manage shift work and jet lag, and serve as a research outcome in chronobiology trials.
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Sources
- Lewy AJ. (1999). The dim light melatonin onset, melatonin assays and biological rhythm research in humans. *Biological Signals and Receptors*doi:10.1159/000014573
- Pandi-Perumal SR, Smits M, Spence W, et al.. (2007). Dim light melatonin onset (DLMO): A tool for the analysis of circadian phase in human sleep and chronobiological disorders. *Progress in Neuro-Psychopharmacology and Biological Psychiatry*doi:10.1016/j.pnpbp.2006.06.020
- Morgenthaler TI, Lee-Chiong T, Alessi C, et al.. (2007). Practice Parameters for the Clinical Evaluation and Treatment of Circadian Rhythm Sleep Disorders. *Sleep*doi:10.1093/sleep/30.11.1445