Melatonin Secretion Pattern in Critically Ill Patients: A Pilot Descriptive Study

Figure 3

Diurnal variation of sleep and melatonin. Melatonin line represents connected mean melatonin values at each sample point. These values are standardized to sleep proportion values to visualize both curves on the same scale on -axis. Normal sleep (AASM standard) and atypical sleep (Watson’s classification) are plotted as the proportions of sleep (normal sleep + atypical sleep + wake + undefined = 100%) over the 24-hour period together with melatonin to visualize diurnal variation of sleep and melatonin.