Reproductive hormones, aging, and sleep

Insomnia, disturbed sleep, and fatigue are among the most frequent health c omplaints of perimenopausal women. Estrogen replacement therapy (ERT) usual ly improves sleep, most likely by alleviating vasomotor symptoms. However, sleep difficulties are not restricted to the perimenopausal period. Older p ostmenopausal women typically experience longer latencies to sleep onset, i ncreased nocturnal waking, increased fragmentation of sleep, and less slow wave (deep) sleep. These sleep changes in older women may be partially rela ted to the postmenopausal profile of sex steroid hormones. Estrogen has pow erful effects on several biological factors that directly influence sleep, including body temperature regulation, circadian rhythms, and stress reacti vity. The link between sleep disturbance in older women and these CNS effec ts of estrogen is largely speculative at present. This article reviews what is known, what remains to be addressed, and some clinical implications.