Evidence for Entrainment of Nocturnal Cortisol Secretion to Sleep Processes in Human Beings

Abstract

The pulsatile patterns of cortisol release have been referred to as ‘episodic’ rather than ‘rhythmic’. We studied plasma cortisol patterns in 31 healthy subjects during night sleep and observed a uniform ultradian rhythm. Using spectral analysis a predominant mean periodicity of 151.2 ± 8.3 min (x ± SEM) was calculated for plasma cortisol oscillations, and of 118.3 ± 4.3 min for REM sleep occurrence. The rhythmic pattern of plasma cortisol was obscured when data were averaged across subjects, due to the individual onset latencies of the initial cortisol rise. Therefore, the data were analyzed time-locked to a number of somnopolygraphic sleep events: by selecting the end of the second sleep cycle as point of reference, the ultradian rhythm was preserved. These results indicate that both sleep processes and nocturnal plasma cortisol concentrations are subject to ultradian rhythms. Both rhythms are coupled, but have different periodicities.

Antimineralocorticoid Canrenoate Enhances Secretory Activity of the Hypothalamus-Pituitary-Adrenocortical (HPA) Axis in Humans

“…In a recent study, central nervous sleep processes have been shown to be influenced by the drug which sig nificantly reduced slow-wave sleep [12]. These findings do not only suggest that canrenoate or its metabolites reach central nervous MR binding sites; together with the present findings, they also suggest that central nervous MRs represent an important physiological link in the well-recognized entrainment between night-time cortisol secretion and sleep processes [19].…”

Sleep-Associated Augmentation and Synchronization of Luteinizing Hormone Pulses in Adult Men

“…Thus, plasma renin activity is always declining or at nadirs during REM sleep [ 13]; human growth hormone is secreted in relation to sleep onset [14], and nocturnal cortisol secretion is related to the second REM epoch [15,16], Taken together, these findings suggest that each sleep cycle has its own and characteristic pat tern of endocrine activities. Entrainment of endocrine secre tions by sleep events could establish constant phase relations of the diverse endocrine rhythms.…”

Basal secretory activity of the hypothalamo–pituitary–adrenocortical axis is enhanced in healthy elderly. An assessment during undisturbed night-time sleep

“…During the second half of nocturnal sleep, secretion is activated. This process is linked closely to the central nervous non-REM (NREM)-REM sleep cycle such that during REM sleep secretory activation is inhibited (18)(19)(20)(21). This link hints at a common ultradian central nervous oscillator regulating the timing of NREM-REM sleep and of the spontaneous rise in nocturnal secretory activity.…”