Figure 2

Serum levels of parameters that showed sensitivity to the CO2 stress test (NA, ACTH, cortisol, IL-6 and leptin), pooled across both groups and all three times of day (n = 143 subjects).
Mean serum levels are indicated by the circles, separately for each of the six time points (error bars represent SEM). Dotted lines are spline interpolations of mean values, thus approximating the time course of parameter levels between the measured time points. The bottom right panel shows z-standardized values so that responsiveness to the stress test can be compared between parameters. ACTH: adrenocorticotropic hormone; IL-6: interleukin-6; NA: noradrenaline.