Objective-The aim of this study was to test the hypothesis that the postmenopausal hot flash is accompanied by rapid decreases in arterial blood pressure and increases in cutaneous vascular conductance (CVC), as evaluated by continuous measurements of these variables in symptomatic women.Design-Twelve healthy, normotensive, postmenopausal women rested in a temperature-controlled laboratory (26°C) for approximately 90 minutes. The onset of a hot flash was objectively identified as a transient and pronounced elevation of sternal sweat rate (capacitance hygrometry).Results-Twenty-three hot flashes were recorded during the experimental sessions (3.4 ± 1.4 min; range, 1.3-6.5 min). Mean arterial blood pressure decreased 13 ± 2 mm Hg during 11 hot flashes in five participants. Data from these participants, categorized as responders, were analyzed separately from data for those participants whose blood pressure did not change during their hot flashes (n = 7, 12 hot flashes). Heart rate (obtained from an electrocardiogram) significantly increased during the hot flashes, but there was no difference between the responder and nonresponder groups (9 ± 2 vs 10 ± 1 beats/min, respectively; P > 0.05). The increase in CVC was not different between groups at either the forearm (15% ± 3% vs 12% ± 3% maximal CVC, P > 0.05) or sternum (24% ± 5% vs 21% 3% maximal CVC, P > 0.05).Conclusions-These data demonstrate that in a subset of participants, the hot flash is accompanied by a significant reduction in blood pressure, but there is no difference in CVC between these women and women with no drop in blood pressure.
KeywordsSkin blood flow; Blood pressure; Hot flash Hot flashes are a primary symptom of female menopause that can seriously disrupt the lives of symptomatic women. 1 Approximately 70% of women experience hot flashes for the first 1 to 5 years after the onset of the menopausal transition. [1][2][3][4] The incidence and severity of symptoms are even higher in women after surgically induced menopause and in female oncology patients. 3,5,6 Hot flashes are typically defined as sudden subjective sensations of heat, frequently accompanied by skin flushing and perspiration, that generally begin in the chest and radiate to the face, head, and arms. 1,4,7,8 Symptomatic women also report a range of additional symptoms during a hot flash, such as anxiety, frustration, embarrassment, nausea, and depression. 1,[8][9][10] Of importance, hot flashes can negatively affect mood, concentration, sleep quality, and sexual function and result in fatigue and stress, 1,11-14 thereby significantly reducing the quality of life and overall health of afflicted women. 2,[14][15][16] Despite the clear disruption that hot flashes cause to the lives of menopausal women, physiological mechanisms associated with hot flashes are not completely understood. Previous research has reported transient increases in hand, calf, and forearm blood flow during hot flashes using plethysmographic techniques.17 The plethysmographic technique, however, provides a d...