Sleep Disturbance and Sympathetic Neural Reactivity in Postmenopausal Females.

Sleep disturbance (SD), one of the most common menopausal symptoms, contributes to autonomic dysfunction and is linked to hypertension and cardiovascular risk. Longitudinal studies suggest that hyperreactivity of blood pressure (BP) to a stressor can predict future development of hypertension. It remains unknown if postmenopausal females who experience SD demonstrate greater hemodynamic and sympathetic neural hyperreactivity to a stressor. We hypothesized that postmenopausal females with reported SD would exhibit increased hemodynamic and sympathetic reactivity to a stressor compared with postmenopausal females without sleep disturbance (NSD). Fifty-five postmenopausal females (age: 62±1yrs; SD, n=36; NSD; n=19) completed two study visits. The Menopause-Specific Quality of Life Questionnaire (MENQOL) was used to assess the presence of SD (MENQOL sleep scale, ≥2 units). Beat-to-beat BP (finger plethysmography), heart rate (HR; electrocardiogram) and muscle sympathetic nerve activity (MSNA; microneurography; SD, n=25; NSD, n=15) were continuously measured during a 10-min baseline and two-min stressor (cold pressor test; CPT) in both groups. Menopause age and body mass index were similar between groups (p>0.05). There were no differences between resting BP, HR, or MSNA (p>0.05). HR and BP reactivity were not different between SD and NSD (p>0.05). In contrast, peak MSNA reactivity (90s) to CPT was elevated in the SD group (burst incidence: Δ22.5±3.1bursts/100hb) compared with the NSD group (burst incidence: Δ14.4±4.1bursts/100hb, time×group, p=0.011). Our results demonstrate augmented sympathetic neural reactivity to CPT in postmenopausal females with self-report SD, a finding that aligns with and advances recent evidence that SD is associated with sympathetic neural hyperactivity in postmenopausal females.