Effects of the menstrual cycle on sympathetic neural responses to mental stress in humans

Abstract

The influence of the menstrual cycle on resting muscle sympathetic nerve activity (MSNA) remains controversial, and the effect of the menstrual cycle on MSNA responses to mental stress is unknown. We examined MSNA, mean arterial pressure (MAP), and heart rate (HR) responses to mental stress (via mental arithmetic) in 11 healthy females during the early follicular (EF) and mid-luteal (ML) phases of the menstrual cycle. The menstrual cycle did not alter resting MSNA (EF, 13 ± 3 bursts min −1 versus ML, 13 ± 2 bursts min −1 ), MAP (EF, 79 ± 3 mmHg versus ML, 81 ± 2 mmHg) and HR (EF, 66 ± 3 beats min −1 versus ML, 64 ± 2 beats min −1 ). 5 min of mental stress increased MSNA, MAP and HR during both the EF (Δ4 ± 2 bursts min −1 , Δ12 ± 2 mmHg, Δ18 ± 2 beats min −1 ; P < 0.05) and ML (Δ4 ± 2 bursts min −1 , Δ13 ± 3 mmHg and Δ20 ± 2 beats min −1 ; P < 0.05) phases. These responses were not different between phases. In contrast, MSNA responses were different between phases during the 10 min recovery from mental stress. MSNA remained elevated during the initial 5 min of recovery in both the EF (Δ6 ± 1 bursts min −1 ; P < 0.01) and ML (Δ7 ± 1 bursts min −1 ; P < 0.01) phases, but only remained elevated during the ML phase (Δ6 ± 1 bursts min −1 ; P < 0.01) during the final 5 min of recovery. Our results demonstrate that MSNA, MAP and HR responses at rest or during mental stress are not different during the EF and ML phases of the menstrual cycle in young, healthy females. However, MSNA activation during recovery from mental stress is prolonged during the ML phase compared to the EF phase.

Study of Cardiovascular Reactivity to Mental Stress in Different Phases of Menstrual Cycle

“…The present study did not notice any differences in the basal heart rate between the phases, which is similar to the findings of many other studies [17][18][19][20]. Similarly the insignificant differences in basal SBP and DBP values in this study were also in concordance with the findings of Sato et al, [11].…”

“…Unlike this, the results in the present study did not show significant variations in cardiovascular reactivity to mental stress between two phases of the menstrual cycle. Similar observations regarding cardiovascular reactivity to stress were also observed by few previous studies [12,13,17] but with a lesser sample size than present study. These observations regarding stress induced cardiovascular reactivity and menstrual cycle in various other studies are provided in [Table /Fig-4].…”

“…Moreover these hormonal fluctuations that occur during normal course of menstrual cycle may alter sympathetic outflow but not necessarily the transduction of sympathetic activity into vascular resistance. Carter et al, [17] also observed similar results in a study conducted on 11 females. The sample size of the present study is 30 which is comparatively better than these three studies.…”

Pain sensitivity and cardiovascular reactivity to the experimental induced cold pressor pain during different phases of menstrual cycle in young Indian females

“…[ [15][16][17] In the same line, a few studies have also reported insignificant differences in the mean arterial pressure. [16,18] This has been suggested to be because the changes in hypothalamic pituitary ovarian axis functioning over the course of the menstrual cycle are barely reflected in resting parameters and which may become prominent when the system is activated by a potent stressor.…”

“…[15][16][17][18][19] The definitive interaction of these physiological characteristics is very meagerly found in literature search, particularly in young Indian females. The results of studies conducted in women, examining the response of experimentally induced noxious stimulation and its variations related to the menstrual phase, did not showed conclusive findings.…”