Sex differences in cardiovascular responses to orthostatic challenge in healthy older persons: A pilot study

Background Premenopausal women show a higher incidence of orthostatic hypotension than age-matched men, but there are limited data available on sex differences in cardiovascular responses to orthostatic challenge in healthy older persons. We investigated sex differences in hemodynamic and autonomic responses to orthostatic challenge in healthy older males and females. Materials and methods Fourteen older healthy women and 10 age-matched men performed a sit-to-stand test (5 min of sitting followed by 5 min of standing). A Task Force® Monitor continuously measured the following beat-to-beat hemodynamic parameters: heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure, stroke index, cardiac index, and total peripheral resistance index. Cardiac autonomic activity, low-frequency (LF: 0.04–0.15 Hz) normalized (LFnuRRI) and high-frequency (HF: 0.15–0.4 Hz) normalized (HFnuRRI) components, and the ratio between LF and HF power (LF/HF) were calculated using power spectral analysis of heart rate variability. Results Across all hemodynamic parameters, there were no significant differences between the sexes at baseline and during standing. LFnuRRI (median: 70.2 vs. 52.3, p < 0.05) and LF/HF ratio (median: 2.4 vs. 1.1, p < 0.05) were significantly higher, whereas HFnuRRI (median: 29.8 vs. 47.7, p < 0.05) was lower among women at baseline. All other heart rate variability measures did not differ between the sexes. Conclusions The data indicate that older women showed higher sympathetic and lower parasympathetic activity at rest compared to age-matched men. These results are contradictory to the observations from previous studies, which showed a reduced sympathetic and enhanced parasympathetic activity in women in all ages. Further studies are required to determine the underlying mechanisms contributing to higher incidence of orthostatic hypotension in older females.

Download Full-text

Ethnic and sex differences in the longitudinal association between heart rate variability and blood pressure

Blood Pressure ◽

10.1080/08037051.2021.1876517 ◽

2021 ◽

pp. 1-7

Author(s):

LaBarron K. Hill ◽

Julian F. Thayer ◽

DeWayne P. Williams ◽

James D. Halbert ◽

Guang Hao ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Sex Differences ◽

Longitudinal Association

Download Full-text

The preponderance of initial orthostatic hypotension in postural tachycardia syndrome

Journal of Applied Physiology ◽

10.1152/japplphysiol.00540.2020 ◽

2020 ◽

Vol 129 (3) ◽

pp. 459-466

Author(s):

Julian M. Stewart ◽

Archana Kota ◽

Mary Breige O’Donnell-Smith ◽

Paul Visintainer ◽

Courtney Terilli ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Blood Flow ◽

Heart Rate Variability ◽

Cerebral Blood Flow ◽

Orthostatic Hypotension ◽

Pressure Recovery ◽

Postural Tachycardia Syndrome ◽

Postural Tachycardia ◽

Initial Orthostatic Hypotension

Significant initial orthostatic hypotension (IOH) occurs in ~50% of postural tachycardia syndrome (POTS) patients and 13% of controls. Heart rate and blood pressure recovery are prolonged in IOH sustaining lightheadedness; IOH is more prevalent and severe in POTS. Altered cerebral blood flow and cardiorespiratory regulation are more prevalent in POTS. Altered heart rate variability and baroreflex gain may cause nearly instantaneous lightheadedness in POTS. IOH alone fails to confer a strong probability of POTS.

Download Full-text

Sex differences in baroreflex sensitivity, heart rate variability, and end organ damage in the TGR(mRen2)27 rat

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00593.2011 ◽

2011 ◽

Vol 301 (4) ◽

pp. H1540-H1550 ◽

Cited By ~ 19

Author(s):

Megan S. Johnson ◽

Vincent G. DeMarco ◽

Cheryl M. Heesch ◽

Adam T. Whaley-Connell ◽

Rebecca I. Schneider ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Sex Differences ◽

Baroreflex Sensitivity ◽

Organ Damage ◽

Left Ventricular ◽

Loop Analysis ◽

Poincaré Plot ◽

End Organ Damage

The aim of this investigation was to evaluate sex differences in baroreflex and heart rate variability (HRV) dysfunction and indexes of end-organ damage in the TG(mRen2)27 (Ren2) rat, a model of renin overexpression and tissue renin-angiotensin-aldosterone system overactivation. Blood pressure (via telemetric monitoring), blood pressure variability [BPV; SD of systolic blood pressure (SBP)], spontaneous baroreflex sensitivity, HRV [HRV Triangular Index (HRV-TI), standard deviation of the average NN interval (SDNN), low and high frequency power (LF and HF, respectively), and Poincaré plot analysis (SD1, SD2)], and cardiovascular function (pressure-volume loop analysis and proteinuria) were evaluated in male and female 10-wk-old Ren2 and Sprague Dawley rats. The severity of hypertension was greater in Ren2 males (R2-M) than in Ren2 females (R2-F). Increased BPV, suppression of baroreflex gain, decreased HRV, and associated end-organ damage manifested as cardiac dysfunction, myocardial remodeling, elevated proteinuria, and tissue oxidative stress were more pronounced in R2-M compared with R2-F. During the dark cycle, HRV-TI and SDNN were negatively correlated with SBP within R2-M and positively correlated within R2-F; within R2-M, these indexes were also negatively correlated with end-organ damage [left ventricular hypertrophy (LVH)]. Furthermore, within R2-M only, LVH was strongly correlated with indexes of HRV representing predominantly vagal (HF, SD1), but not sympathetic (LF, SD2), variability. These data demonstrated relative protection in females from autonomic dysfunction and end-organ damage associated with elevated blood pressure in the Ren2 model of hypertension.

Download Full-text

The influence of low-intensity resistance training combined with neuromuscular electrical stimulation on autonomic activity in healthy adults: A randomized controlled cross-over trial

Hong Kong Physiotherapy Journal ◽

10.1142/s1013702521500013 ◽

2020 ◽

pp. 1-9

Author(s):

Toshiki Kutsuna ◽

Hitoshi Sugawara ◽

Hideaki Kurita ◽

Satomi Kusaka ◽

Tetsuya Takahashi

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Electrical Stimulation ◽

Neuromuscular Electrical Stimulation ◽

Cardiovascular Responses ◽

Healthy Adults ◽

Autonomic Activity ◽

Low Intensity ◽

Randomized Controlled

Background: Low-intensity resistance training (RT) combined with neuromuscular electrical stimulation (NMES) is one method of exercise to improve the deterioration of physical function. However, it is unclear whether low-intensity RT combined with NMES (RT + NMES) can be safely implemented. Objective: This study aimed to examine the influence of low-intensity RT + NMES on autonomic activity and cardiovascular responses in healthy adults. Methods: This study was an open-label, randomized controlled cross-over trial. The exercise intensity of isometric knee extension RT was set to 40% of the maximum voluntary contraction (peak torque). NMES was adjusted to a biphasic asymmetrical waveform with the frequency maintained at 50 Hz and a phase duration of 300 [Formula: see text]s. The difference in the change in autonomic activity and cardiovascular responses was compared by assessing heart rate variability, blood pressure, and heart rate during RT and [Formula: see text]. Results: Twenty healthy male college students (mean age [Formula: see text] years) participated in this study. The ratio of low- and high-frequency components of heart rate variability, systolic blood pressure, and heart rate increased during exercise in the RT and [Formula: see text] sessions ([Formula: see text]). There were no significant differences in autonomic activity and cardiovascular responses throughout the sessions during RT and [Formula: see text]. Conclusion: In conclusion, our results demonstrated that low-intensity [Formula: see text] was safe and did not induce excessive autonomic and cardiovascular responses in healthy adults.

Download Full-text

Sleep Deprivation Deteriorates Heart Rate Variability and Photoplethysmography

Frontiers in Neuroscience ◽

10.3389/fnins.2021.642548 ◽

2021 ◽

Vol 15 ◽

Author(s):

Nicolas Bourdillon ◽

Fanny Jeanneret ◽

Masih Nilchian ◽

Patrick Albertoni ◽

Pascal Ha ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Sleep Deprivation ◽

Sympathetic Activity ◽

Cardiovascular Health ◽

Cardiovascular Responses ◽

Vigilance Task ◽

Parasympathetic Activity ◽

Subjective Fatigue ◽

Partial Sleep Deprivation

IntroductionSleep deprivation has deleterious effects on cardiovascular health. Using wearable health trackers, non-invasive physiological signals, such as heart rate variability (HRV), photoplethysmography (PPG), and baroreflex sensitivity (BRS) can be analyzed for detection of the effects of partial sleep deprivation on cardiovascular responses.MethodsFifteen participants underwent 1 week of baseline recording (BSL, usual day activity and sleep) followed by 3 days with 3 h of sleep per night (SDP), followed by 1 week of recovery with sleep ad lib (RCV). HRV was recorded using an orthostatic test every morning [root mean square of the successive differences (RMSSD), power in the low-frequency (LF) and high-frequency (HF) bands, and normalized power nLF and nHF were computed]; PPG and polysomnography (PSG) were recorded overnight. Continuous blood pressure and psychomotor vigilance task were also recorded. A questionnaire of subjective fatigue, sleepiness, and mood states was filled regularly.ResultsRMSSD and HF decreased while nLF increased during SDP, indicating a decrease in parasympathetic activity and a potential increase in sympathetic activity. PPG parameters indicated a decrease in amplitude and duration of the waveforms of the systolic and diastolic periods, which is compatible with increases in sympathetic activity and vascular tone. PSG showed a rebound of sleep duration, efficiency, and deep sleep in RCV compared to BSL. BRS remained unchanged while vigilance decreased during SDP. Questionnaires showed an increased subjective fatigue and sleepiness during SDP.ConclusionHRV and PPG are two markers easily measured with wearable devices and modified by partial sleep deprivation, contradictory to BRS. Both markers showed a decrease in parasympathetic activity, known as detrimental to cardiovascular health.

Download Full-text

Orthostatic hypotension in aging humans

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2000.279.4.h1548 ◽

2000 ◽

Vol 279 (4) ◽

pp. H1548-H1554 ◽

Cited By ~ 28

Author(s):

Xiangrong Shi ◽

D. Walter Wray ◽

Kevin J. Formes ◽

Hong-Wei Wang ◽

Patrick M. Hayes ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Orthostatic Hypotension ◽

Parasympathetic Nervous System ◽

Lower Body Negative Pressure ◽

The Elderly ◽

Sympathetic Blockade ◽

Lower Body ◽

Younger Adults ◽

Orthostatic Challenge

We tested the hypothesis that hypotension occurred in older adults at the onset of orthostatic challenge as a result of vagal dysfunction. Responses of heart rate (HR) and mean arterial pressure (MAP) were compared between 10 healthy older and younger adults during onset and sustained lower body negative pressure (LBNP). A younger group was also assessed after blockade of the parasympathetic nervous system with the use of atropine or glycopyrrolate and after blockade of the β1-adrenoceptor by use of metoprolol. Baseline HR (older vs. younger: 59 ± 4 vs. 54 ± 1 beats/min) and MAP (83 ± 2 vs. 89 ± 3 mmHg) were not significantly different between the groups. During −40 Torr, significant tachycardia occurred at the first HR response in the younger subjects without hypotension, whereas significant hypotension [change in MAP (ΔMAP) −7 ± 2 mmHg] was observed in the elderly without tachycardia. After the parasympathetic blockade, tachycardiac responses of younger subjects were diminished and associated with a significant hypotension at the onset of LBNP. However, MAP was not affected after the cardiac sympathetic blockade. We concluded that the elderly experienced orthostatic hypotension at the onset of orthostatic challenge because of a diminished HR response. However, an augmented vasoconstriction helped with the maintenance of their blood pressure during sustained LBNP.

Download Full-text

Acute cardiovascular responses to a session of Manual Lymphatic Drainage

Fisioterapia em Movimento ◽

10.1590/0103-5150.028.001.ao04 ◽

2015 ◽

Vol 28 (1) ◽

pp. 41-48 ◽

Cited By ~ 1

Author(s):

Plínio dos Santos Ramos ◽

Isabelle Regina Moreira Marinho Cunha ◽

Mariana Cristina Rachel ◽

Priscilla Stephan Souza Pacca ◽

Ana Paula Ferreira ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Young Women ◽

Interstitial Fluid ◽

Cardiovascular Responses ◽

Lymphatic Drainage ◽

Point Of View ◽

Hemodynamic Parameters ◽

Manual Lymphatic Drainage ◽

Hemodynamic Changes

Introduction Manual Lymphatic Drainage (MLD) creates pressure differentials to promote the movement of lymph and interstitial fluid, for their relocation into the bloodstream and can thus act on the variables responsible for determining blood pressure (BP). Objective To investigate the behavior of hemodynamic parameters, such as BP and Heart Rate (HR) during and immediately after a session of MLD. Materials and methods 23 healthy young volunteers with a mean age of 22 ± 2.97 years (18-29), underwent a session of MLD and evaluation of systolic BP, diastolic BP and HR after 10 minutes of initial rest, at the end of the implementation of the protocol in SP, PP and after 15 minutes of final rest. Results No changes were found in systolic BP or diastolic BP before, during and immediately after the MLD session (p = 0.57, p = 0.20, respectively). There was increased heart rate after the final 15 minute rest when compared to the HR after MLD in SP (72 ± 1.9 vs. 76 ± 1.9, p = 0.002), however, without clinical relevance. Conclusion During a session of MLD with healthy young women, no significant hemodynamic changes occurred, demonstrating that this technique is safe from the cardiovascular point of view.

Download Full-text

Heart rate variability responses to hypoxic and hypercapnic exposures in different mouse strains

Journal of Applied Physiology ◽

10.1152/japplphysiol.00039.2005 ◽

2005 ◽

Vol 99 (3) ◽

pp. 807-813 ◽

Cited By ~ 28

Author(s):

Matthew J. Campen ◽

Yugo Tagaito ◽

Todd P. Jenkins ◽

Alex Balbir ◽

Christopher P. O’Donnell

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

High Frequency ◽

Inbred Mice ◽

Strain Differences ◽

Cardiovascular Responses ◽

Mouse Strains ◽

Cardiac Autonomic Nervous System ◽

Arterial Blood

Heart rate variability (HRV) is a well-characterized, noninvasive means of assessing cardiac autonomic nervous system activity. This study examines the basic cardiac responses to hypoxic and hypercapnic challenges in seven strains of commonly used inbred mice (A/J, BALB/cJ, C3H/HeJ, C57BL/6J, CBA/J, DBA/2J, and FVB/J). Adult male mice, 8–12 wk of age, were chronically instrumented to a femoral artery catheter for the continuous measurement of systemic arterial blood pressure and heart rate. Mice were exposed to multiple 4-min periods of hypoxia (10% O2), hypercapnia (5% CO2), and combined hypoxia/hypercapnia (10% O2 + 5% CO2). HRV was derived from pulse intervals of the blood pressure tracings. Hypoxia induced increases in high-frequency HRV power and decreased low-frequency (LF) HRV power in most strains. Hypercapnia led to decreased high-frequency HRV power and increased LF HRV power in most strains. Strain differences were most notable in regard to the concomitant exposures of hypoxia and hypercapnia, with FVB/J mice mirroring their own response to hypercapnia alone, whereas CBA/J mice mirrored their own responses to hypoxia. As blood pressure is most likely the driving factor for heart rate changes via the baroreflex pathway, it is interesting that LF, considered to reflect cardiac sympathetic activity, was negatively correlated with heart rate, suggesting that LF changes are driven by baroreflex oscillation and not necessarily by absolute sympathetic or parasympathetic activity to the heart. These findings suggest that genetic background can influence the centrally mediated cardiovascular responses to basic hypoxic and hypercapnic challenges.

Download Full-text

Cardiovascular Variability and Reactivity in Major Depressive Disorder

Journal of Psychophysiology ◽

10.1027/0269-8803/a000277 ◽

2021 ◽

pp. 1-14

Author(s):

Stefan Duschek ◽

Angela Bair ◽

Alexandra Hoffmann ◽

Josef Marksteiner ◽

Casandra I. Montoro ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Major Depressive Disorder ◽

Depressive Disorder ◽

Diastolic Blood Pressure ◽

Blood Pressure Variability ◽

Cardiovascular Responses ◽

Major Depressive ◽

Cardiovascular Variability

Abstract. This study investigated cardiovascular variability and stress reactivity in major depressive disorder (MDD). While previous research has documented reduced heart rate variability, knowledge about blood pressure variability in MDD remains scarce. Regarding reactivity, a particular focus was placed on the time courses of the cardiovascular responses, which may provide insight into the autonomic mechanisms underlying the hypo-reactivity expected in MDD. In 76 MDD patients and 71 healthy controls, blood pressure was continuously recorded at rest and during mental stress induced by a 3-min serial subtraction task. Compared to controls, patients exhibited lower systolic and diastolic blood pressure, heart rate variability, and systolic and diastolic blood pressure variability. Moreover, smaller stress-related changes in heart rate, systolic and diastolic blood pressure, and sensitivity of the cardiac baroreflex arose in patients. Cardiovascular parameters did not differ between patients using antidepressants and unmedicated patients. According to time-course analysis, reduced hemodynamic modulations in MDD mainly occurred after 50 s of the stress period. Low heart rate variability in MDD reflects deficient top-down integration of the brain mechanisms allowing flexible autonomic and behavioral control; diminished blood pressure variability is indicative of poor homeostatic capacity with respect to the regulation of blood pressure and organ perfusion. Moreover, blunted cardiovascular reactivity implies poor adjustment of energetic resources to internal and environmental demands and may be a correlate of deficient motivational dynamics characterizing MDD. While cardiovascular hypo-reactivity in MDD may be mediated by baroreflex and adrenergic mechanisms, the fast-acting parasympathetic system may play a subordinate role.

Download Full-text