Vasomotor symptoms of menopause and sympathetic and blood pressure reactivity to exercise
Females who experience increased frequency and severity of vasomotor symptoms (VMS: hot flushes/night sweats) demonstrate a greater cardiovascular disease (CVD) risk (1). VMS is associated with elevated blood pressure (BP) and hypertension (HTN) is the greatest risk factor for CVD (2). Exaggerated BP reactivity during exercise can be associated with an increased risk for CVD. Postmenopausal females have greater BP and sympathetic reactivity to exercise than premenopausal females (4), but it is unclear if postmenopausal females with VMS demonstrate an increased BP and sympathetic reactivity to exercise. Thus, the purpose of this study is to determine if postmenopausal females with VMS experience a greater BP and sympathetic reactivity to exercise. We hypothesize that females who experience VMS have an exaggerated BP and sympathetic response to exercise compared with females without VMS. In this study 38 postmenopausal females attended two study visits. Visit 1 included informed written consent. A medical history questionnaire and Menopause-Specific Quality of Life questionnaire (MENQOL) was completed. Participants were classified as “No VMS'' or “VMS” based on their vasomotor MENQOL scores. Visit 2 occurred after an overnight fast. Participants were asked to abstain from caffeine, exercise, and alcohol for 12 hours prior to the study visit. Three maximum voluntary contractions (MVC) of the non-dominant hand to measure peak strength. Continuous noninvasive BP, heart rate via three-lead electrocardiography (ADInstruments, Colorado Springs, CO), and muscle sympathetic nerve activity (MSNA) via microneurography of the peroneal nerve were measured. After a three-minute baseline rest, continuous isometric hand grip (IHG) at 30% of peak MVC force to fatigue was conducted. Lastly, blood draws were performed to measure sex hormone levels. It was found that both VMS and Non-VMS females had a significant increase in BP, HR, and MSNA during exercise. Females with VMS had similar increases in BP, HR and sympathetic reactivity during exercise compared with females without VMS. Next steps include investigating these responses in females more severe and frequent VMS as the VMS group in this study had mild symptoms (2.4 out of 8).