DIURNAL SLEEP WAKE-RELATED IMMUNE FUNCTIONS DURING THE MENSTRUAL-CYCLE OF HEALTHY-YOUNG WOMEN

Animal and human studies have related the sleeping/waking brain to the immune system. Because women are more susceptible to certain immunolo gical illnesses, and sex steroids regulate immune functions, it was in vestigated whether the diurnal sleep/wake pattern of aspects of cellul ar immune functions and interleukin-l (IL-1) and IL-2-like activities differed during low and high progesterone phases of the menstrual cycl e. Eleven healthy women, mean age 24 y, were assessed over 24 h with s erial venous blood samples, Peripheral blood monocytes were assayed fo r mitogen responses, i.e. phytohemagglutin (PHA) and pokeweed (PWM) an d natural killer (NK) cell activities. Plasma was assayed for IL-1 and IL-2-like activities, cortisol and progesterone. Data were standardiz ed by Z transformation and analysed by repeated-measures analysis of v ariance by comparing high (N = 5) vs. low (N = 6) progesterone phases. During the high progesterone phase, delayed slow-wave sleep (SWS) ons et time and reduced amount of SWS was accompanied by a delay in the de cline of NK cell activity, but rise in PHA activity following sleep on set. With the low progesterone phase, the pattern was similar to men w ith an early sleep decline in NK cell and late sleep rise in PHA activ ities. PWM rose during the night and plasma IL-l-like activity peaked during midday and during nocturnal sleep irrespective of the amount of progesterone. Slow-wave sleep and sleep-related NK cell and PHA activ ities differed over the menstrual cycle, but not PWM response. Increas es in plasma IL-1 functions during midday and night are consistent wit h predisposition to sleepiness during these times.