Impact of Sleep and Its Disturbances on Hypothalamo-Pituitary-Adrenal Axis Activity

Figure 1

24-hour individual cortisol profile (solid line).The smoothing curve (dotted line) is calculated to determine the minimum (nadir), the maximum (acrophase), the onset of the circadian rise, and the amplitude (50% of the difference between the acrophase and the nadir) of the cortisol profile. The black bar represents the sleep period.