Calculating the Dim Light Melatonin Onset: The Impact of Threshold and Sampling Rate

Abstract

The dim light melatonin onset (DLMO) is the most reliable circadian phase marker in humans, but the cost of assaying samples is relatively high. Therefore, the authors examined differences between DLMOs calculated from hourly versus half-hourly sampling and differences between DLMOs calculated with two recommended thresholds (a fixed threshold of 3 pg/mL and a variable “3k” threshold equal to the mean plus two standard deviations of the first three low daytime points). The authors calculated these DLMOs from salivary dim light melatonin profiles collected from 122 individuals (64 women) at baseline. DLMOs derived from hourly sampling occurred on average only 6–8 min earlier than the DLMOs derived from half-hourly saliva sampling, and they were highly correlated with each other (r ≥ 0.89, p < .001). However, in up to 19% of cases the DLMO derived from hourly sampling was >30 min from the DLMO derived from half-hourly sampling. The 3 pg/mL threshold produced significantly less variable DLMOs than the 3k threshold. However, the 3k threshold was significantly lower than the 3 pg/mL threshold (p < .001). The DLMOs calculated with the 3k method were significantly earlier (by 22–24 min) than the DLMOs calculated with the 3 pg/mL threshold, regardless of sampling rate. These results suggest that in large research studies and clinical settings, the more affordable and practical option of hourly sampling is adequate for a reasonable estimate of circadian phase. Although the 3 pg/mL fixed threshold is less variable than the 3k threshold, it produces estimates of the DLMO that are further from the initial rise of melatonin.

Comparing the Morningness-Eveningness Questionnaire and Munich ChronoType Questionnaire to the Dim Light Melatonin Onset

“…The DLMO was calculated as the clock time (with linear interpolation) when the melatonin concentration exceeded the mean of 3 low consecutive daytime/early evening values plus twice the standard deviation of these points (Voultsios et al, 1997). This low threshold more closely tracks the initial rise of melatonin, when the SCN triggers the release of melatonin from the pineal gland (Molina and Burgess, 2011). The Rush University Medical Center Institutional Review Board approved all of the study protocols from which the data were pooled, and the study protocols followed the principles of the Declaration of Helsinki.…”

Individually tailored light intervention through closed eyelids to promote circadian alignment and sleep health

“…The different techniques were employed to account for individual differences in the observed melatonin profiles and to account for the fact that four subjects did not provide enough saliva for melatonin assay at the latter part of the night (31). The 3L method was used for those subjects with steep melatonin profiles whereas the 5H/5L method was used for those with shallow melatonin profiles.…”

Chronotyp und Depression bei Jugendlichen – ein Review

“…Schultage und freie Tage (Roenneberg, Kuehnle, et al, 2007 Randler, 2009;Smith, Reilly, & Midkiff, 1989) oder die Morningness-EveningnessSubskala des School Sleep Habits Survey (Carskadon, Vieira, & Acebo, 1993) (Roenneberg et al, 2015), der Zeitpunkt der abendlichen Melatonin-Ausschüttung (Molina & Burgess, 2011) und seltener auch der morgendliche Peak der Cortisol-Ausschüttung (Clow, Hucklebridge, Stalder, Evans, & Thorn, 2010). Studien zur Validierung des MEQ zeigten, dass der Peak der Körperkerntemperatur (Bailey & Heitkemper, 2001;Griefahn, Künemund, Bröde, & Mehnert, 2001;Horne & Ostberg, 1976;Ishihara & Miyasita, 1987), der Cortisol-Ausschüttung (Bailey & Heitkemper, 2001) als auch der Zeitpunkt der abendlichen Melatonin-Ausschüttung (Griefahn et al, 2001) (Murray & Lopez, 1996) und Jugendliche besonders späte Chronotypen sind (Roenneberg et al, 2004 Typische Symptome der Depression wie Interessensverlust und Antriebslosigkeit gehen häufig mit sozialem Rückzug einher (Gotlib, 1992;Hagerty, Williams, Coyne, & Early, 1996).…”