Effects of sex steroids on sleep

Sex steroid secretions are generally synchronous with the circadian rhythm and sleep, and there is evidence that prolactin secretion is sleep-dependen t. Polysomnographically assessed changes in sleep during the menstrual cycl e are characterized by increased EEG activity in the 14-15-Hz (sleep spindl e) range in the luteal phase accompanying an increase in core temperature. There are no other consistent changes in sleep architecture associated with the menstrual cycle. The hot sweats which disturb sleep in menopausal wome n are attributable to oestrogen deficiency and are reduced by oestrogen rep lacement therapy. Although it is often assumed that the psychological chang es during the menopause are attributable to chronic sleep disturbance cause d by hot sweats, the evidence for this is uncertain. Sex steroids have also been shown to have a role in the aetiology of obstructive sleep apnoea and its treatment. It is clear that the sex steroids are all implicated in sle ep and thermoregulatory processes, although we cannot as yet define their p recise roles.