Are vasomotor symptoms associated with sleep characteristics among symptomatic midlife women? Comparisons of self-report and objective measures

Objective: Many women report vasomotor symptoms (VMS) and sleep problems during the menopausal transition. Although reported VMS are consistently related to reported sleep disturbance, findings using physiologic measures of VMS or sleep have been more mixed. Our objective was to examine whether more VMS during sleep are associated with poorer sleep among midlife women with VMS using physiologic measures of both VMS and sleep. Methods: A subcohort of participants (N = 52) with VMS, a uterus and both ovaries, and free of medications affecting VMS from the Pittsburgh site of the Study of Women's Health Across the Nation underwent four 24-hour periods of in-home ambulatory VMS and sleep measurement. Measures included sternal skin conductance for the measurement of VMS, actigraphy for assessing sleep, a VMS diary, and a sleep diary completed before bed and upon waking. Associations between VMS and sleep were evaluated using generalized estimating equations with covariates age, body mass index, medications affecting sleep, race, financial strain, and depressive symptoms. Results: More VMS recalled upon waking were associated with significantly lower actigraphy-assessed sleep efficiency, significantly higher wakefulness after sleep onset, and somewhat longer sleep latency. Conversely, physiologically measured VMS and VMS reported during the night were largely unrelated to sleep characteristics. Conclusions: Associations between VMS and sleep may depend more on the awareness of and recall of VMS rather than solely on their physiologic occurrence.