Differences in arterial stiffness at rest and after acute exercise between young men and women

The effect of different proximities to failure on arterial stiffness following resistance training protocols matched for volume-load

This study compared acute changes in measures of arterial stiffness (AS) between two resistance training (RT) protocols that were load, volume and rest matched, but differed in intensity of effort. Eleven healthy adults (36.4 ± 6.8 years) performed a RT protocol with high intensity of effort (HE) and a RT protocol with low intensity of effort (LE). The HE protocol consisted of 3 sets of 12 repetitions, while the LE comprised of 6 sets of 6 repetitions. Loading intensity, volume load, and total rest duration were equivalent between the RT sessions. Pulse wave velocity, augmentation index values collected at baseline, immediately post and 15 min post-exercise. HE elicited significantly greater increases in carotid-femoral pulse wave velocity (6.4 ± 0.3 to 7.3 ± 0.5 m/s) when compared to LE (6.6 ± 0.3 to 6.7 ± 0.3 m/s) (p < 0.05). Both HE and LE induced significant increases in augmentation index (13 ± 5.6 to 28.1 ± 9.3%) post exercise (all p < 0.05). These findings demonstrate that RT with a lower intensity of effort attenuate increases in measures of arterial stiffness compared to a RT scheme at higher intensity of effort when volume load and total rest are equalized.

Effects of Exercise on Arterial Stiffness: Mechanistic Insights into Peripheral, Central, and Systemic Vascular Health in Young Men

BACKGROUND/OBJECTIVES

Arterial stiffness, a critical predictor of cardiovascular events, varies regionally across peripheral, central, and systemic arteries, necessitating targeted exercise interventions for young men. However, research on the effects of exercise on arterial stiffness in these regions among young men remains limited. This review aims to (i) examine the effects of exercise on arterial stiffness in young men across these regions, and (ii) investigate the underlying mechanisms involved.

METHODS

Database searches on PubMed, ScienceDirect, Web of Science, and Scopus were conducted up to July 2024. The keywords were: exercise, men/male, and arterial stiffness. Inclusion criteria were studies involving young men, supervised exercise, and arterial stiffness measures. Thirty-five papers were categorized into groups based on peripheral, central and systemic arterial stiffness.

RESULTS

Peripheral arterial stiffness: continuous aerobic cycling (light to high intensity), interval aerobic cycling (moderate to high intensity), and 30-s stretching exercises demonstrated positive effects, likely due to short-term changes in sympathetic nervous system activity, nitric oxide availability, and vascular tone. Central arterial stiffness: chronic high-intensity continuous and interval aerobic cycling exercises promoted vascular remodeling, including elastin preservation and collagen regulation. For systemic arterial stiffness, continuous and interval aerobic cycling and light-intensity squats with whole-body vibration exercises improve endothelial function, smooth muscle relaxation, and vascular remodeling.

CONCLUSIONS

Tailored exercise intervention can effectively reduce arterial stiffness across peripheral, central and systemic regions in young men. Improvements in peripheral stiffness are linked to short-term metabolic shifts, central stiffness responds to long-term remodeling, while systemic arterial stiffness involves both short- and long-term metabolic adaptations.

Central blood pressure and peripheral augmentation index following acute submaximal arm versus leg exercise

BACKGROUND

Aerobic exercises like running and cycling may lower cardiovascular disease (CVD) risk through favorable effects on central blood pressure and vascular function. Arm ergometry is a popular exercise modality used in rehabilitation settings, but little is known regarding the central hemodynamic and vascular effects of this form of exercise.

PURPOSE

To compare the acute effects of leg versus arm exercise on central blood pressure and vascular function.

METHODS

Twenty-one participants (n = 11 female, Age 21 ± 3, BMI 24.5 ± 3.2 kg/m2) completed two visits to the Human Performance Laboratory. Central systolic blood pressure (cSBP), central diastolic blood pressure (cDBP), and peripheral augmentation index (pAIx) were measured using a brachial oscillometric blood pressure cuff with measures being taken before and after 20 min of acute moderate-intensity (submaximal) arm or leg cycling exercise.

RESULTS

There was a condition-by-time interaction for pAIx (p = 0.011). pAIx slightly increased following arm exercise but significantly decreased following leg exercise. There was a condition-by-time interaction for cDBP (p = 0.011). cDBP significantly decreased following arm exercise but increased immediately following leg exercise. There was no condition-by-time interaction for cSBP (p = 0.721). There were similar acute increases in cSBP immediately post-exercise for both conditions.

CONCLUSION

Arm exercise increased pAlx and decreased cDBP compared to leg exercise. As an increase in pAIx may increase left ventricular work and a reduction in cDBP may reduce coronary perfusion pressure, these findings suggest that a single bout of arm exercise may not have the same favorable acute effect on central hemodynamic load as a single bout of leg exercise.

Acute cardiovascular responses to the 100-mi Western States Endurance Run

Ultramarathon participation is growing in popularity and exposes runners to unique stressors including extreme temperatures, high altitude, and exceedingly long exercise duration. However, the acute effects of ultramarathon participation on the cardiovascular system are not well understood. To determine the acute effects of trail ultramarathon participation on central artery stiffness and hemodynamics, 41 participants (9 F, 32 M) participating in the 2023 Western States Endurance Run underwent measures of carotid-femoral pulse wave velocity (cf-PWV) and pulse wave analysis pre- and <1 h post-race. Subendocardial viability ratio (SEVR) was calculated from central blood pressure (BP) waveforms. Serum was analyzed for creatine kinase (CK) activity as a measure of muscle damage. Normally distributed data are presented as means ± standard deviation (SD), and nonnormally distributed data are presented as median (interquartile range). Runners were middle-aged and generally lean [age = 44 ± 9 yr, body mass index (BMI) = 22.7 ± 1.8 kg·m-2]. There was no difference in cf-PWV from pre- to post-race (pre = 6.4 ± 1.0, post = 6.2 ± 0.85 m/s, P = 0.104), a finding that persisted after adjusting for mean arterial pressure (P = 0.563). Systolic and diastolic BPs were lower post-race (pre = 129/77 ± 9/7, post = 122/74 ± 10/8 mmHg, P < 0.001). Augmentation index (AIx; pre = 17.3 ± 12.2, post = 6.0 ± 13.7%, P < 0.001), AIx normalized to a heart rate of 75 beats/min (P = 0.043), reflection magnitude (pre = 55.5(49.0-60.8), post = 45.5(41.8-48.8)%, P < 0.001), and SEVR (pre = 173.0(158.0-190.0), post = 127.5(116.5-145.8)%, P < 0.001) were reduced post-race. CK increased markedly from pre- to post-race (pre = 111(85-162), post = 11,973(5,049-17,954) U/L, P < 0.001). Completing a 161-km trail ultramarathon does not affect central arterial stiffness and acutely reduces BP despite eliciting profound muscle damage. However, the reduced post-race SEVR suggests a short-term mismatch between myocardial work and coronary artery perfusion.NEW AND NOTEWORTHY Ultramarathon participation is growing dramatically. However, the acute cardiovascular effects of completing a 161-km trail ultramarathon remain unknown. We examined the acute effects of completing the 2023 Western States Endurance Run on arterial stiffness and central hemodynamics in a relatively large sample of males and females. We observed dramatic postexercise hypotension, reductions in reflected wave amplitude and reduced subendocardial viability ratio post-race. These findings suggest that ultramarathon participation has few negative effects on cardiovascular health.

Sex Differences in Heart Rate Variability and Vascular Function Following High-Intensity Interval Training in Young Adults

High-intensityintervaltraining (HIIT) issuperiortoothertrainingstrategies in both male andfemalehealthyindividuals. Understanding sex-specificdifferences in cardiac auto-regulation maycontributetothe optimal trainingstrategiesfor HIIT. The presentstudyaimedtoidentifysexdifferences in heart rate variability (HRV) andvascularfunctionfollowing HIIT in youngadults. Twenty-fourphysicallyactiveyoung male andfemaleadults (M: 12, F: 12, age: 19.5 yr, BMI: 22.1 kg·m-2) volunteeredtoparticipate in thestudy. Participantsperformed 10 boutsof HIIT including 20 s of high-intensitycycling at 115-130% Wmaxfollowedby 100 s ofrecovery. The cardiac auto-regulationsincluding HRV andvascularfunctionweremeasured at five different time points. The R-R interval, rMSSD, and SDNN wererecoveredfaster in malesthan in females after 15 min of HIIT. Thereweresexdifferences in theautonomicnervoussystemwhereln LF andln HF activitiesalongwithsympathovagalbalance (ln LF/HF) weregreater in femalescomparedwithmalesimmediatelyand 15 min after HIIT. However, nosignificantdifferences in bloodpressureand brachial-ankle pulse wavevelocitywereobservedbetween male andfemaleparticipants. Overall, HRV was moreactivated in femalesthan in malesfollowing HIIT, but theacuteresponse in vascularfunction was not different betweensexes. In futurestudies, sex-specificadaptationsofcardiacautoregulationfollowingrepeated HIIT mayneedtobeperformed.

Barosensory vessel mechanics and the vascular sympathetic baroreflex: Impact on blood pressure homeostasis

NEW FINDINGS

What is the topic of this review? We review barosensory vessel mechanics and their role in blood pressure regulation across the lifespan. What advances does it highlight? In young normotensive men, aortic unloading mechanics contribute to the resting operating point of the vascular sympathetic baroreflex; however, with advancing age, this contribution is removed. This suggests that barosensory vessel unloading mechanics are not driving the well-documented age-related increase in resting muscle sympathetic nerve activity.

ABSTRACT

An age-associated increase in arterial blood pressure is evident for apparently healthy humans. This is frequently attributed to stiffening of the central arteries and a concurrent increase in sympathetic outflow, potentially mediated by a reduced ability of the baroreceptive vessels to distend. This is supported, in part, by a reduced mechanical component of the vascular sympathetic baroreflex (i.e., a reduction in distension for a given pressure). Previous characterization of the mechanical component has assessed only carotid artery distension; however, evidence suggests that both the aortic and carotid baroreflexes are integral to blood pressure regulation. In addition, given that baroreceptors are located in the vessel wall, the change in wall tension, comprising diameter, pressure and vessel wall thickness, and the mechanics of this change might provide a better index of the baroreceptor stimulus than the previous method used to characterize the mechanical component that relies on diameter alone. This brief review summarizes the data using this new method of assessing barosensory vessel mechanics and their influence on the vascular sympathetic baroreflex across the lifespan.

Female cardiovascular biology and resilience in the setting of physiological and pathological stress

For years, females were thought of as smaller men with complex hormonal cycles; as a result, females have been largely excluded from preclinical and clinical research. However, in the last ten years, with the increased focus on sex as a biological variable, it has become clear that this is not the case, and in fact, male and female cardiovascular biology and cardiac stress responses differ substantially. Premenopausal women are protected from cardiovascular diseases, such as myocardial infarction and resultant heart failure, having preserved cardiac function, reduced adverse remodeling, and increased survival. Many underlying biological processes that contribute to ventricular remodeling differ between the sexes, such as cellular metabolism; immune cell responses; cardiac fibrosis and extracellular matrix remodeling; cardiomyocyte dysfunction; and endothelial biology; however, it is unclear how these changes afford protection to the female heart. Although many of these changes are dependent on protection provided by female sex hormones, several of these changes occur independent of sex hormones, suggesting that the nature of these changes is more complex than initially thought. This may be why studies focused on the cardiovascular benefits of hormone replacement therapy in post-menopausal women have provided mixed results. Some of the complexity likely stems from the fact that the cellular composition of the heart is sexually dimorphic and that in the setting of MI, different subpopulations of these cell types are apparent. Despite the documented sex-differences in cardiovascular (patho)physiology, the underlying mechanisms that contribute are largely unknown due to inconsistent findings amongst investigators and, in some cases, lack of rigor in reporting and consideration of sex-dependent variables. Therefore, this review aims to describe current understanding of the sex-dependent differences in the myocardium in response to physiological and pathological stressors, with a focus on the sex-dependent differences that contribute to post-infarction remodeling and resultant functional decline.

What Is the Smallest Change in Pulse Wave Velocity Measurements That Can Be Attributed to Clinical Changes in Arterial Stiffness with Certainty: A Randomized Cross-Over Study

Pulse wave velocity (PWV), a direct measure of arterial stiffness, is a promising biomarker of cardiovascular risk and a cardiovascular surrogate outcome. The resolution for detecting its smallest clinically significant change is dependent on the expected reproducibility, but there is currently no consensus on this. We estimated the PWV reproducibility in a range of intra-subject values that were observed over a 2 week period in a broad range of participants and under clinically relevant experimental conditions (two observers, morning/afternoon sessions, and number of visits) using SphygmoCor and Arteriograph devices. Each participant was recorded 12 times with each device over three visits, one week apart, and two morning and two afternoon recordings were taken per visit. The factors affecting reproducibility and the discrepancies between the consecutive PWV measurements for each device were also examined using multilevel mixed-effect models. We show that current PWV estimation guidance recommending 2 + 1 measurements is suboptimal because the PWV range was outside of the 1 m/s threshold for most of the participants, which is proposed as a minimal clinically important difference. The best reproducibility was yielded with median of four measurements and a 1.1 m/s threshold. Although PWV reproducibility and repeatability are frequently used interchangeably in studies, we demonstrated that despite their relative measures of variability (e.g., coefficient of variation) being comparable, their ranges revealed a clinically significant difference between them. We also found that different physiological variables were predictors of the discrepancy between the consecutive measurements made by the two devices, which is likely due to their distinct modes of operation. The evidence base for PWV reproducibility is limited, and more research is needed to deepen our understanding of the variation in arterial stiffness over time, as well as fluctuations within a population group and in an intervention setting.

Effect of Exercise on Arterial Stiffness in Healthy Young, Middle-Aged and Older Women: A Systematic Review

Arterial stiffness, an age-dependent phenomenon, is improved with exercise, which in turn may prevent cardiovascular diseases in women. However, there is a lack of consolidated information on the impact of exercise on arterial stiffness among healthy women. The aim of this review was to (i) analyse the effect of exercise on arterial stiffness in healthy young, middle-aged, and older women, and (ii) recommend types, intensity, and frequency for each age group. Database searches on PubMed, ScienceDirect, Web of Science, and Scopus were conducted using PRISMA guidelines until September 2022. The keywords were: exercise, women/female, and arterial stiffness. The inclusion criteria were: healthy women, supervised exercise, and arterial stiffness measures. Study quality and bias were assessed using the PEDro scale. Fifty-one papers were classified into young (n = 15), middle-aged (n = 14), and older (n = 22) women. Improvements in arterial stiffness were observed among: young women (Pulse Wave Velocity, PWV: 4.9-6.6 m/s), following an 8-week high-intensity aerobic (3 days/week) or hypoxic high-intensity interval training; middle-aged women (PWV: 5.1-7.9 m/s), aerobic exercise with moderate intensity or stretching exercise at "moderate to heavy" (Borg Scale), 20-30 s per site, 10 s of rest interval for 30 min; and for older women (PWV: 7.9-15.6 m/s), resistance training at light intensity, aerobic exercise at any intensity, or a combination of the two exercises. This review shows that arterial stiffness increases with age in healthy women and has an inverse relationship with exercise intensity. Therefore, when prescribing exercise to improve arterial stiffness, age and arterial stiffness measures should be accounted for.

Arterial Stiffness Response to Acute Combined Training with Different Volumes in Coronary Artery Disease and Heart Failure Patients

Resistance training has been shown to acutely increase arterial stiffness (AS), while endurance training appears to decrease AS. However, the findings are from studies in apparently healthy subjects and have limited applicability to patients at low and high cardiovascular risk, for whom combined exercise is recommended. We compared the time course of changes in local and regional indices of AS in response to high-volume combined endurance training (CET) and high-volume combined resistance training (CRT) in patients with coronary artery disease (CAD) and heart failure (HF). We studied 20 men with CAD and HF (10 each) aged 68.3 ± 9.6 years. AS was measured by pulse wave velocity (PWV), and brachial and central blood pressure (BP) were determined after 15 min of rest and 5 and 15 min after the exercise session. All patients completed two sessions on nonconsecutive days. A protocol by time interaction effect was observed for carotid (η² = 0.21, p = 0.02), aortic (η² = 0.60, p < 0.001), and femoral (η² = 0.46, p = 0.01) PWV after CET and CRT, suggesting that PWV decreased after CET and increased after CRT. Decreases in the brachial and central variables of BP across time points were observed in both protocols. CET decreased whereas CRT increased carotid, aortic, and femoral PWV at 15 min after exercise in patients with CAD and HF.

Arterial Stiffness following Endurance and Resistance Exercise Sessions in Older Patients with Coronary Artery Disease

Arterial stiffness (AS) is associated with coronary artery disease (CAD). Acute endurance training decreases AS, whereas acute resistance training increases it. However, these results are from studies in apparently healthy adults, and there is no information on the effects of such afterload AS in elderly patients with CAD. We aimed to investigate the effect of acute endurance or resistance training on the time course of changes in the indices of AS in elderly patients with CAD in order to understand how stiffness responds after training. We tested 18 trained men with CAD. AS was measured using central and peripheral pulse wave velocity (PWV) after 15 min of rest and after 5, 15, and 30 min of endurance and resistance training sessions. The endurance session consisted of high-intensity interval walking at 85-90% of maximum heart rate, and the resistance session consisted of 70% of the maximum of one repetition. An interaction effect was found for central and peripheral PWV (p ≤ 0.001; carotid, η² = 0.72; aortic, η² = 0.90; femoral, η² = 0.74), which was due to an increase in PWV after resistance and a decrease in central and peripheral PWV after endurance. This study demonstrates that training mode influences the time course of AS responses to acute exercise in these patients. Acute endurance training decreased AS, whereas resistance training significantly increased it.

Changes in Arterial Stiffness in Response to Various Types of Exercise Modalities: A Narrative Review on Physiological and Endothelial Senescence Perspectives

Arterial stiffness is a reliable independent predictor of cardiovascular events. Exercise training might enhance arterial compliance through improved metabolic health status. Different modes of exercise may have different effects on arterial stiffness. However, the interactions among different modes of exercise on endothelial senescence, the development of arterial vascular stiffness, and the associated molecular mechanisms are not completely understood. In this narrative review, we evaluate the current evidence focusing on the effects of various exercise modes on arterial stiffness and vascular health, and the known underlying physiological mechanisms are discussed as well. Here, we discuss the most recent evidence of aerobic exercise, high-intensity interval training (HIIT), and resistance exercise (RE) on arterial stiffness and endothelial senescence in physiological and cellular studies. Indeed, aerobic, HIIT, and progression RE-induced arterial compliance may reduce arterial stiffness by effectively promoting nitric oxide (NO) bioavailability and reducing endothelial senescence. However, the transient increase in inflammation and sympathetic activation may contribute to the temporary elevation in arterial stiffness following whole-body high-intensity acute resistance exercise.

High-intensity functional exercise does not cause persistent elevations in augmentation index in young men and women

Elevations in central augmentation index (AIx) are predictive of cardiovascular disease. Our objective was to examine AIx immediately and 24-hrs following an acute bout of high-intensity functional training (HIFT) in apparently healthy young adults. A second aim compared the exercise induced AIx recovery response between men and women. Thirty-two recreationally active younger adults (n=16 men) were tested. Baseline central hemodynamic measures were assessed, followed by a single bout of bodyweight HIFT. The HIFT included four rounds of burpees, jump squats, split squats, and walking lunges. Assessments were repeated 5-, 10-, 15- and 24-hrs post exercise. AIx was normalized to a heart rate of 75 bpm (AIx75). There was a significant main effect of time on AIx75 across all groups (p<0.001) with AIx75 increasing at all acute timepoints compared with baseline and returning to resting values 24-hrs post-exercise. When examining sex differences after covarying for height and body fat percentage, we found no time*sex interaction (p=0.62), or main effect for sex (p=0.41), but the significant main effect of time remained (p<0.001). The AIx75 response to HIFT follows a similar recovery pattern as previously studied modes of exercise with no residual effects 24 hrs later and no differences between men and women indicating no persistent cardiovascular strain in younger adults participating in this mode of exercise.

Sex Matters: A Comprehensive Comparison of Female and Male Hearts

Cardiovascular disease in women remains under-diagnosed and under-treated. Recent studies suggest that this is caused, at least in part, by the lack of sex-specific diagnostic criteria. While it is widely recognized that the female heart is smaller than the male heart, it has long been ignored that it also has a different microstructural architecture. This has severe implications on a multitude of cardiac parameters. Here, we systematically review and compare geometric, functional, and structural parameters of female and male hearts, both in the healthy population and in athletes. Our study finds that, compared to the male heart, the female heart has a larger ejection fraction and beats at a faster rate but generates a smaller cardiac output. It has a lower blood pressure but produces universally larger contractile strains. Critically, allometric scaling, e.g., by lean body mass, reduces but does not completely eliminate the sex differences between female and male hearts. Our results suggest that the sex differences in cardiac form and function are too complex to be ignored: the female heart is not just a small version of the male heart. When using similar diagnostic criteria for female and male hearts, cardiac disease in women is frequently overlooked by routine exams, and it is diagnosed later and with more severe symptoms than in men. Clearly, there is an urgent need to better understand the female heart and design sex-specific diagnostic criteria that will allow us to diagnose cardiac disease in women equally as early, robustly, and reliably as in men.

Systematic Review Registration

https://livingmatter.stanford.edu/.

Differences between Elite Male and Female Badminton Athletes Regarding Heart Rate Variability, Arterial Stiffness, and Aerobic Capacity

Cardiovascular health and aerobic capacity play crucial roles in determining the performance of athletes in the highly competitive sport of badminton. Few studies have directly compared heart rate variability (HRV), arterial stiffness, and aerobic capacity between male and female athletes, especially among badminton athletes. This study investigated sex differences in HRV, arterial stiffness, and aerobic capacity in badminton athletes. Elite badminton athletes were recruited and divided into male (n = 20, 21.0 ± 1.8 years old) and female (n = 16, 21.2 ± 2.3 years old) groups. Both groups performed an incremental treadmill running test for the evaluation of maximal oxygen consumption (V.O2max), anaerobic threshold, and time to exhaustion. They started exercising at a treadmill speed of 2.7 km/h and an inclination of 10% gradient for 3 min, and the speed and inclination were gradually increased every 3 min until they were exhausted or fatigued volitionally. HRV was examined using the Polar heart rate monitor over a period of 5 min at rest in the supine position. Subsequently, the index of arterial stiffness was examined under the same condition. Our results revealed significant differences between the male and female athletes in V.O2max (men: 60.38 ± 8.98 mL/kg/min, women: 48.13 ± 7.72 mL/kg/min, p < 0.05), anaerobic threshold (men: 41.50 ± 7.26 mL/kg/min, women: 32.51 ± 6.19 mL/kg/min, p < 0.05), time to exhaustion (men: 902.15 ± 120.15 s, women: 780.56 ± 67.63 s, p < 0.05), systolic blood pressure (men: 125.27 ± 7.76 mmHg, women: 107.16 ± 11.09 mmHg, p < 0.05), and arterial stiffness index (men: 63.56 ± 12.55, women: 53.83 ± 8.03, p < 0.05). However, no significant differences in HRV measures were observed between the two groups. These findings suggested that the male badminton athletes demonstrated significantly higher aerobic capacity than did the female athletes, but there were no significant differences in HRV measures. The female athletes exhibited superior arterial function, compared with their male counterparts.

Infrared sauna as exercise-mimetic? Physiological responses to infrared sauna vs exercise in healthy women: A randomized controlled crossover trial

BACKGROUND

Passive heat therapies have been reported to have similar effects on the cardiovascular system as exercise. Studies supporting these findings in healthy populations have predominantly been done with men using warm water immersions or traditional saunas, rather than newer infrared-based saunas.

OBJECTIVE

To explore short-term thermal and cardiovascular responses in women using an infrared sauna as compared to moderate-intensity exercise.

STUDY DESIGN

Randomized controlled crossover trial with balanced allocations.

SETTING

Brisbane, Australia (August 2019 - March 2020) PARTICIPANTS: Ten healthy women (36 ± 9 years) INTERVENTIONS: 45 min of resting, infrared sauna or indoor bicycling PRIMARY OUTCOME MEASURES: tympanic/skin temperatures; respiratory rate; blood pressure; arterial stiffness; heart rate variability RESULTS: Tympanic temperatures were elevated during infrared sauna as compared to both control (mean diff = +1.05 ^oC ± SEM 0.12 ^oC, 95% C.I.: 0.73 - 1.36, p < 0.0005) and exercise (mean diff = +0.79 ^oC ± SEM 0.12 ^oC, 95% C.I.: 0.49 - 1.08, p < 0.0005). Respiratory rates were higher during exercise as compared to both control (mean diff = +7.66 ± SEM 1.37, 95% C.I.: 4.09 - 11.23, p < 0.0005) and infrared sauna (mean diff = +6.66 ± SEM 1.33, 95% C.I.: 3.20 - 10.11, p < 0.0005). No significant differences in non-invasive measures of blood pressure, arterial stiffness or heart rate variability were detected between any of the interventions.

CONCLUSIONS

These findings suggest the physiological effects of infrared sauna bathing are underpinned by thermoregulatory-induced responses, more so than exercise-mimetic cardiorespiratory or cardiovascular activations.

Effects of a 12-Week Resistance Training Program on Arterial Stiffness: A Randomized Controlled Trial

ABSTRACT

Werner, TJ, Pellinger, TK, Rosette, VD, and Ortlip, AT. Effects of a 12-week resistance training program on arterial stiffness: a randomized controlled trial. J Strength Cond Res 35(12): 3281-3287, 2021-Arterial stiffness is an indicator of disease and is an independent predictor of cardiovascular events. Some reports indicate that resistance training increases indices of arterial stiffness, whereas others report no association. This study sought to determine the association between 2 common resistance training models and indices of arterial stiffness. We recruited 30 male, untrained subjects (18-30 years) and randomized them into 1 of 3 groups: control (CON, n = 10), high-intensity resistance exercise (HI, n = 10), and high-volume resistance exercise (HV, n = 10). Subjects randomized to the resistance training groups were required to perform whole-body strength training exercises 3-5 days a week for 12 weeks. The exercise regimen consisted of 2-3 sets of 3-8 repetitions (80-90% of 1 repetition maximum [1RM]) for the HI group and 3-4 sets of 10-15 repetitions (50-70% of 1RM) for the HV group. Anthropometry, carotid artery diameters, peripheral and central blood pressure, and maximal dynamic strength were measured before and after the 12-week study period. Subjects were instructed to maintain their normal diet and avoid aerobic exercise during the study. After the intervention, both the HI and HV groups increased their maximal strength on the back squat, bench press, and seated row (all p < 0.05). However, there were no changes in arterial stiffness indices between the groups. Using a randomized controlled trial with validated measurements of arterial stiffness, chronic resistance training does not appear to influence central arterial stiffness, regardless of training volume and load.

Hemodynamic response and pulse wave analysis after upper- and lower-body resistance exercise with and without blood flow restriction

Resistance exercise (RE) has been shown to elevate hemodynamics and pulse wave reflection. However, the effects of acute RE with blood flow restriction (BFR) on hemodynamics and pulse wave reflection are unclear. The purpose of this study was to evaluate the differences between upper- and lower-body RE with and without BFR on hemodynamics and pulse wave reflection. Twenty-three young resistance-trained individuals volunteered for the study. Hemodynamics and pulse wave reflection were assessed at rest, 10, 25, 40, and 55 min after either upper- or lower-body with or without BFR. The upper-body RE (URE) consisted of the latissimus dorsi pulldown and chest press; the lower-body RE (LRE) consisted of knee extension and knee flexion. The BFR condition consisted of four sets of 30, 15, 15, and 15 repetitions at 30% 1-repetition maximum (1RM) while the without BFR condition consisted of four sets of 8 repetitions at 70% 1RM. Heart rate, rate pressure product, and subendocardial viability ratio significantly (p < 0.05) increased after all exercises. Brachial and aortic systolic blood pressure (BP) significantly (p < 0.05) elevated after LRE while brachial and aortic diastolic BP significantly (p < 0.05) reduced after URE. Augmentation pressure, augmentation index (AIx), AIx normalized at 75 bpm, and wasted left ventricular pressure energy significantly (p < 0.05) increased after URE while transit time of reflected wave significantly (p < 0.05) decreased after LRE. URE places greater stress on pulse wave reflection while LRE results in greater responses in BP. Regardless of URE or LRE, the cardiovascular responses between BFR and without BFR are similar.HIGHLIGHTS High-load resistance exercise and low-load resistance exercise with blood flow restriction may produce similar cardiovascular responses.Upper-body resistance exercise generates greater changes on pulse wave reflections while lower-body resistance exercise induces greater elevations in systolic blood pressure.

Sex differences in cardiovascular adaptations in recreational marathon runners

INTRODUCTION

There are well-established sex differences in central hemodynamic and cardiac adaptations to endurance exercise; however, controversial evidence suggests that excessive endurance exercise may be related to detrimental cardiovascular adaptations in marathoners.

PURPOSE

To examine left ventricle (LV) structure, LV function, 24-h central hemodynamics and ventricular-vascular coupling in male and female marathoners and recreationally active adults.

METHODS

52 marathoners (41 ± 5 years, n = 28 female, completed 6 ± 1 marathons/3 years) and 49 recreationally active controls (42 ± 5 years, n = 25 female) participated in the study. Three-Dimensional Echocardiography (3DE) was used to measure LV mass index and LV longitudinal (LS) circumferential (CS), area (AS), and radial strain (RS). An ambulatory blood pressure (BP) cuff was used to measure 24-h central hemodynamics (BP, pulse wave velocity, PWV, wave reflection index, RIx). Hemodynamic and 3DE measures were combined to derive the ratio of arterial elastance (Ea) to ventricular elastance (Elv) as a global measure of ventricular-vascular coupling.

RESULTS

There were no sex or group differences in LS, CS, AS, and RS (p > 0.05). Females marathoners had similar aortic BP (116 ± 9 vs. 113 ± 1 mmHg), and PWV (5.9 ± 0.5 vs. 5.9 ± 1.1 m/s) compared to female controls but lower aSBP (116 ± 9 vs. 131 ± 10 mmHg) and PWV (5.9 ± 0.5 vs. 6.2 ± 0.5 m/s) compared to male marathoners (p < 0.05). Female marathoners had lower Ea/Elv than female controls (0.67 ± 0.20 vs. 0.93 ± 0.36) and male marathoners (0.67 ± 0.20 vs. 0.85 ± 0.42, p < 0.05).

CONCLUSIONS

Women that have completed multiple marathons do not have reduced LV function or increased aortic stiffness and may have better ventricular-vascular coupling compared to male marathoners and their female untrained counterparts.

Prolonged Elevation of Arterial Stiffness Following Peak Aerobic Exercise in Individuals With Chronic Stroke

Background

Stroke is a highly disabling condition and is the second leading cause of death globally. Engaging in aerobic exercise is important for the prevention of a recurrent stroke through improving markers of cardiovascular health such as blood pressure and arterial stiffness. While higher intensities of aerobic exercise generally elicit greater cardioprotective effects, little is known about the acute cardiovascular effects of a single session of high intensity aerobic exercise in people with stroke. The objective of this study was to model the recovery of arterial stiffness (carotid-femoral pulse wave velocity, cfPWV), heart rate and blood pressure following peak intensity aerobic exercise in individuals with chronic stroke.

Methods

Ten participants with chronic stroke (mean ± SD age = 56.9 ± 11.8 years, median [IQR] years post-stroke = 2.9 [1.9]) performed a symptom-limited cardiopulmonary exercise test (CPET) on a recumbent stepper. Before the CPET, resting cfPWV, heart rate and blood pressure were measured. Immediately following the CPET, all outcomes were measured again continuously for 20 min to use all available observations (n = 245 observations) and capture any potential non-linear changes. Mixed model analyses were then applied to model post-exercise changes of cfPWV, heart rate and blood pressure.

Results

Carotid-femoral pulse wave velocity was increased from rest following the CPET (9.0 ± 0.53 to 9.9 ± 0.52 m/s, p < 0.001) and remained elevated for 20 min into post-exercise recovery, independent of heart rate (p = 0.001). Heart rate also increased from baseline (71.2 ± 3.2 to 77.4 ± 3.1 bpm, p < 0.001) and remained elevated for 10 min post-exercise (p < 0.001). Finger systolic blood pressure was reduced from rest (117.3 ± 4.7 to 111.8 ± 4.6 mmHg, p < 0.001) and remained reduced for 15 min after exercise (p < 0.001). There were no significant differences in finger diastolic or mean arterial pressures from rest.

Conclusion

This was the first study to capture continuous changes in cfPWV following peak aerobic exercise in any clinical population. The present study revealed that cfPWV is elevated for 20 min after peak aerobic exercise in individuals with stroke, which was independent of heart rate. These findings suggest there may be autonomic imbalances in large arteries following peak intensity aerobic exercise in individuals with stroke.

Arterial Function after a 246 km Ultra-marathon Running Race

There is little research about the effects of ultra-endurance exercise on arterial morphological and functional properties. The aim was to assess the acute changes of the carotid-femoral pulse wave velocity and carotid doppler-derived parameters following an ultra-marathon race as well as the intima-media thickness of the carotid artery in ultra-marathon runners. Twenty athletes were examined at baseline and within 10 mins after a 246 km running race. Measurements included carotid-femoral pulse wave velocity, peak-systolic and end-diastolic velocities of carotid artery blood flow, pulsatility and resistivity indices and blood biochemical parameters. The intima-media thickness of the right and left carotid artery was measured before the race. Arterial stiffness and carotid artery intima media thickness at rest remained within known normal limits. The ultra-marathon race significantly increased carotid-femoral pulse wave velocity by 22.6% and pulsatility index by 10.2%. There was a decrease in body weight by 3.35% and an increase of all biochemical markers of muscle damage after the race. Additionally, C-reactive protein was correlated with both pulsatility and resistivity indices post-race. This study shows that immediately after a 246 km ultra-marathon running race, acute increase of arterial stiffness and vascular resistance were evident. The carotid artery thickness of ultra-marathon runners was within normal range.

Vascular Responses to High-Intensity Battling Rope Exercise between the Sexes

The purpose of the study was to assess high-intensity battling rope exercise (HI-BRE) on hemodynamics, pulse wave reflection and arterial stiffness during recovery and between sexes. Twenty-three young, healthy resistance-trained individuals (men: n = 13; women: n = 10) were assessed for all measures at Rest, as well as 10-, 30-, and 60-minutes following HI-BRE. A one-way repeated measures ANOVA was used to analyze the effects of HI-BRE across time (Rest, 10, 30, and 60-minutes) on all dependent variables. Significant main effects were analyzed using paired t-tests with a Sidak correction factor. Significance was accepted a priori at p 0.05. There were significant reductions in hemodynamic measures of diastolic blood pressure (BP) in women, but not men following HI-BRE at 30 minutes. Further, measures of pulse wave reflection, specifically those of the augmentation index (AIx) and wasted left ventricular energy (ΔE_w), were significantly increased in both men and women for 60 minutes, but changes were significantly attenuated in women suggesting less ventricular work. There were also significant increases in arterial stiffness in regard to the aorta and common carotid artery that were fully recovered by 30 and 60 minutes, respectively with no differences between men and women. Thus, the primary findings of this study suggest that measures of hemodynamics and pulse wave reflection are collectively altered for at least 60 minutes following HI-BRE, with women having attenuated responses compared to men.

Dietary fat and alcohol in the prediction of indices of vascular health among young adults

OBJECTIVES

Arterial stiffness, particularly of the aorta, is an independent predictor of future cardiovascular disease, all-cause mortality, and hypertension. Arterial stiffening may be caused or exacerbated by the composition of the diet. Current research has indicated that habitual dietary patterns may influence arteriosclerosis, or the thickening and hardening of the artery walls, but has yet to identify a specific food group as the culprit. In young, college-aged adults, dietary fat intake and alcohol consumption tend to be higher compared to other periods throughout the life cycle. Therefore, the purpose of this study was to determine the influence of dietary fat and alcohol consumption on the vascular health of apparently healthy young adults.

METHODS

The data collected were assessed to determine if dietary fat and alcohol in young (18-30 y), college-aged adults (n = 50) were independent predictors of an increase in arterial stiffening. Vascular health was determined by the carotid-femoral pulse-wave velocity and the augmentation index corrected for a heart rate of 75 beats/min; dietary patterns were assessed using the Dietary Health Questionnaire II.

RESULTS

The gold standard marker of aortic stiffness, carotid femoral pulse-wave velocity, was positively correlated with cheese consumption (R² = 0.092, P = 0.033), alcohol consumption (R² = 0.102, P = 0.024), and total energy/calories (%) from alcohol (R² = 0.118, P = 0.015) in univariate analysis. In forward-selection multiple regression analysis, energy from alcohol and cheese consumption accounted for 23.7% of the variance in carotid-femoral pulse-wave velocity (P = 0.009). The augmentation index wave reflection marker was positively correlated with total dietary fat (R² = 0.110, P = 0.019), trans fatty acids (R² = 0.092, P = 0.032), saturated fatty acids (R² = 0.124, P = 0.012), monounsaturated fatty acids (R² = 0.012, P = 0.015), red-meat consumption (R² = 0.094, P = 0.030), and discretionary fat from solids in univariate analysis (R² = 0.137, P = 0.008). Discretionary fat from solids accounted for 13.7% of the variation in augmentation index in forward-selection multiple regression analysis (P = 0.008).

CONCLUSIONS

These results indicate the potential roles of dietary fat and alcohol consumption in early vascular aging by stiffening the arteries of young, college-aged adults, which may in turn contribute to future adverse cardiovascular disease outcomes.

Methodological considerations for the measurement of arterial stiffness using applanation tonometry

INTRODUCTION

Accurate comparisons of carotid--femoral pulse wave velocity (cfPWV) within and across studies require standardized procedures. Guidelines suggest reporting the average of at least two cfPWV measurements; if the difference exceeds 0.5 m/s, a third measurement should be taken, and the median reported. Another method involves repeating measurements until two values are within 0.5 m/s. However, in many studies, duplicate measurements are averaged irrespective of the difference between readings. We evaluated the impact of these methods on the reported cfPWV value.

METHODS

Measurements of cfPWV (SphygmoCor) from five studies included individuals spanning a wide age range, with or without comorbid conditions, and pregnant women. In participants with at least three high-quality measurements, differences between the median value (MED) and the average of the first two cfPWV measurements (AVG1) and the average of two cfPWV measurements within 0.5 m/s (AVG2) were evaluated using paired t-tests and Bland--Altman plots.

RESULTS

Participants' mean age was 50 ± 14 years and BMI was 28.0 ± 5.5 kg/m2 (N = 306, 79% women). The overall mean difference was -0.10 m/s (95% CI 0.17 to -0.04) between MED and AVG1, and 0.11 m/s (95% CI 0.05--0.17) between MED and AVG2. The absolute difference exceeded 0.5 m/s in 34% (MED-AVG1) and 22% (MED-AVG2) of participants, and 1 m/s in 8% of participants (both MED-AVG1 and MED-AVG2). Scatter around the bias line increased with higher mean cfPWV values.

CONCLUSION

Although the overall mean difference in cfPWV between protocols was not clinically relevant, large variation led to absolute differences exceeding 0.5 m/s in a large proportion of participants.

Non-Invasive Ultrasound Detection of Cerebrovascular Changes in a Mouse Model of Traumatic Brain Injury

Traumatic brain injury (TBI) can induce changes in vascular architecture. Although ultrasound metrics such as pulsatility index (PI) are sensitive to changes in hemodynamic resistance downstream from major arteries, these metrics depend on features unrelated to vessel architecture, such as blood pressure and heart rate. In contrast, input impedance and reflection coefficient that are derived from wave reflection theory seek to minimize the effects of altered cardiac output or heart rate. In this article, we investigate the use of ultrasound to assess changes in vascular impedance and wave reflection in the common carotid arteries of mice exposed to a controlled cortical impact. Focusing on the first harmonics of the reflected waves, the impedance phase was increased ipsilaterally in impacted mice compared with shams, whereas the magnitude of the impedance was unchanged. In contrast, PI was reduced bilaterally. Interestingly, PI and the first harmonic magnitude of input impedance in the carotid artery were correlated on the contralateral but not ipsilateral side. We investigated the use of these metrics to classify mice as sham or TBI, finding an area under the receiver operating characteristic curve ipsilaterally of 0.792 (confidence interval [CI]: 0.648-0.936) for correct classification with first harmonic impedance magnitude and phase as predictors and 0.716 (CI: 0.553-0.879) using carotid artery PI and diameter as predictors. Overall, the findings support the use of wave reflection analysis as a more specific measure of vascular changes following TBI and motivate the translation of this approach for monitoring vascular changes in humans affected by TBI.

Antioxidant cocktail following a high-sodium meal does not affect vascular function in young, healthy adult humans: a randomized controlled crossover trial

Chronic high sodium intake is a risk factor for cardiovascular disease as it impairs vascular function through an increase in oxidative stress. The objective of this study was to investigate the acute effects of a high-sodium meal (HSM) and antioxidant (AO) cocktail on vascular function. We hypothesized that a HSM would impair endothelial function, and increase arterial stiffness and wave reflection, while ingestion of the AO cocktail would mitigate this response. Healthy adults ingested either an AO cocktail (vitamin C, E, alpha-lipoic acid) or placebo (PLA) followed by a HSM (1500 mg) in a randomized crossover blinded design. Blood pressure (BP), endothelial function (flow-mediated dilation; FMD) and measures of arterial stiffness (pulse wave velocity; PWV) and wave reflection (augmentation index; AIx) were made at baseline and 30, 60, 90, and 120 min after meal consumption. Forty-one participants (20M/21W; 24 ± 1 years; BMI 23.4 ± 0.4 kg/m²) completed the study. Mean BP increased at 120 min relative to 60 min (60 min: 79 ± 1; 120 min: 81 ± 1 mmHg; time effect P = .01) but was not different between treatments (treatment × time interaction P = .32). AIx decreased from baseline (time effect P < .001) but was not different between treatments (treatment × time interaction P = .31). PWV (treatment × time interaction, P = .91) and FMD (treatment × time interaction P = .65) were also not different between treatments. In conclusion, a HSM does not acutely impair vascular function suggesting young healthy adults can withstand the acute impact of sodium on the vasculature and therefore, the AO cocktail is not necessary to mitigate the response.

A pilot study of the effects of a high-intensity aerobic exercise session on heart rate variability and arterial compliance in adolescents with or without type 1 diabetes

Arterial compliance and autonomic regulation are predictors of cardiovascular disease. In adults, both are altered chronically by type 1 diabetes (T1D) and acutely by exercise; however, the effects of T1D and exercise are less clear in adolescents. We measured short-term effects of a high-intensity aerobic interval exercise session on cardiovascular and metabolic variables in normal weight adolescents with T1D or without T1D (Control). Energy expenditure (EE), heart rate variability (HRV), arterial compliance, and blood pressure (BP) were measured before exercise (baseline) and three times over 105 minutes postexercise. The T1D and control groups had similar cardiorespiratory fitness and accelerometer-measured physical activity. The T1D group had higher EE and fat oxidation throughout the trial, but postexercise changes were similar between groups. HRV transiently declined following exercise in both groups, but the T1D group had lower HRV at baseline. Among the measures of arterial compliance, the augmentation index declined postexercise while carotid-femoral pulse wave velocity and large artery elastic index remained unchanged. Central and brachial BP were unchanged following exercise until the final measurement, when a small increase occurred. However, arterial compliance and BP did not differ between groups. These results demonstrate that normal weight adolescents with T1D have impaired autonomic function and increased EE and fat oxidation compared to peers without diabetes who have similar levels of fitness and physical activity. However, acute cardiometabolic responses to exercise are normal in T1D with adequate glycemic control. Changes in arterial compliance and BP may take longer to emerge in relatively healthy adolescents with T1D.

Model-based analysis of arterial pulse signals for tracking changes in arterial wall parameters: a pilot study

Arterial wall parameters (i.e., radius and viscoelasticity) are prognostic markers for cardiovascular diseases (CVD), but their current monitoring systems are too complex for home use. Our objective was to investigate whether model-based analysis of arterial pulse signals allows tracking changes in arterial wall parameters using a microfluidic-based tactile sensor. The sensor was used to measure an arterial pulse signal. A data-processing algorithm was utilized to process the measured pulse signal to obtain the radius waveform and its first-order and second-order derivatives, and extract their key features. A dynamic system model of the arterial wall and a hemodynamic model of the blood flow were developed to interpret the extracted key features for estimating arterial wall parameters, with no need of calibration. Changes in arterial wall parameters were introduced to healthy subjects ([Formula: see text]) by moderate exercise. The estimated values were compared between pre-exercise and post-exercise for significant difference ([Formula: see text]). The estimated changes in the radius, elasticity and viscosity were consistent with the findings in the literature (between pre-exercise and 1 min post-exercise: - 11% ± 4%, 55% ± 38% and 28% ± 11% at the radial artery; - 7% ± 3%, 36% ± 28% and 16% ± 8% at the carotid artery). The model-based analysis allows tracking changes in arterial wall parameters using a microfluidic-based tactile sensor. This study shows the potential of developing a solution to at-home monitoring of the cardiovascular system for early detection, timely intervention and treatment assessment of CVD.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Influence of Exercise Mode on Post-exercise Arterial Stiffness and Pressure Wave Measures in Healthy Adult Males

Background: Exercise mode has been reported to be an important determinant of arterial stiffness and wave reflection changes following a brief bout of exercise with inconsistent results to date. This study examined the impact of exercise mode on arterial stiffness and pressure wave measures following acute aerobic exercise (AER), resistance exercise (RES), and a control (CON) condition with no exercise. Methods: In a randomized, cross-over, repeated measures design, 21 healthy adult males (26.7 ± 7.2 years) undertook three experimental intervention sessions: AER (30-min cycle ergometry at 70-75% maximum heart rate), RES (3 × 10 repetitions of six upper and lower body exercises at 80-90% of 10-repetition maximum) and CON (30-min seated rest). Measures of arterial stiffness and pressure waves, such as carotid-femoral pulse wave velocity (cf-PWV), augmentation index (AIx), AIx corrected for heart rate of 75 (AIx75), and forward wave (Pf), backward wave (Pb) and reflection magnitude, were assessed at Rest and at 10-min intervals for 60 min after the intervention sessions. Comparisons between interventions and over time were assessed via repeated measures ANOVA and post-hoc Tukey's tests. Results: No significant differences in cf-PWV were noted between the three interventions at rest or post-intervention. However, RES led to significantly greater post-intervention AIx, AIx75, Pf, and Pb compared to AER and CON with AIx75 also remaining significantly elevated throughout the post-intervention period. In contrast, AER resulted in a brief, significant elevation of AIx75 and no change in cf-PWV, Pf, Pb, and reflection magnitude. Conclusions: Exercise mode, specifically RES and AER, significantly influenced the time course of pressure wave reflection responses following a brief bout of exercise in healthy adult males. Distinct adjustments during exercise including changes in blood pressure and vasomotor tone may be key modulators of post-exercise arterial function. Identification of modal differences may assist in understanding the impact of exercise on cardiovascular function and the mechanisms by which exercise benefits vascular health.

New insights into arterial stiffening: does sex matter?

This review discusses sexual dimorphism in arterial stiffening, disease pathology interactions, and the influence of sex on mechanisms and pathways. Arterial stiffness predicts cardiovascular mortality independent of blood pressure. Patients with increased arterial stiffness have a 48% higher risk for developing cardiovascular disease. Like other cardiovascular pathologies, arterial stiffness is sexually dimorphic. Young women have lower stiffness than aged-matched men, but this sex difference reverses during normal aging. Estrogen therapy does not attenuate progressive stiffening in postmenopausal women, indicating that currently prescribed drugs do not confer protection. Although remodeling of large arteries is a protective adaptation to higher wall stress, arterial stiffening increases afterload to the left ventricle and transmits higher pulsatile pressure to smaller arteries and target organs. Moreover, an increase in aortic stiffness may precede or exacerbate hypertension, particularly during aging. Additional studies are needed to elucidate the mechanisms by which females are protected from arterial stiffness to provide insight into its mechanisms and, ultimately, therapeutic targets for treating this pathology.

Effects of exercise intensity and cardiorespiratory fitness on the acute response of arterial stiffness to exercise in older adults

PURPOSE

Increased arterial stiffness is observed with ageing and in individuals with low cardiorespiratory fitness ([Formula: see text]O_2peak), and associated with cardiovascular risk. Following an exercise bout, transient arterial stiffness reductions offer short-term benefit, but may depend on exercise intensity. This study assessed the effects of exercise intensity on post-exercise arterial stiffness in older adults with varying fitness levels.

METHODS

Fifty-one older adults (72 ± 5 years) were stratified into fitness tertiles ([Formula: see text]O_2peak: low-, 22.3 ± 3.1; mid-, 27.5 ± 2.4 and high-fit 36.3 ± 6.5 mL kg^-1 min^-1). In a randomised order, participants underwent control (no-exercise), moderate-intensity continuous exercise (40% of peak power output; PPO), and higher-intensity interval exercise (70% of PPO) protocols. Pulse wave velocity (PWV), augmentation index (AIx75) and reflection magnitude (RM) were assessed at rest and during 90 min of recovery following each protocol.

RESULTS

After control, delta PWV increased over time (P < 0.001) and delta RM was unchanged. After higher-intensity interval exercise, delta PWV (P < 0.001) and delta RM (P < 0.001) were lower to control in all fitness groups. After moderate-intensity continuous exercise, delta PWV was not different from control in low-fit adults (P = 0.057), but was lower in the mid- and higher-fit older adults. Post-exercise AIx75 was higher to control in all fitness groups (P = 0.001).

CONCLUSIONS

In older adults, PWV increases during seated rest and this response is attenuated after higher-intensity interval exercise, regardless of fitness level. This attenuation was also observed after moderate-intensity continuous exercise in adults with higher, but not lower fitness levels. Submaximal exercise reveals differences in the arterial stiffness responses between older adults with higher and lower cardiorespiratory fitness.

Acute effects of repeated bouts of aerobic exercise on arterial stiffness after glucose ingestion

The aim of this study was to investigate the acute repeated bouts of aerobic exercise decrease leg arterial stiffness. However, the influence of repeated bouts of aerobic exercise on arterial stiffness after glucose ingestion is unknown. The present study investigates the acute effects of repeated bouts of aerobic exercise on arterial stiffness after the 75-g oral glucose tolerance test (OGTT). Ten healthy young men (age, 23.2 ± 0.9 years) performed repeated bouts of aerobic exercise trial (RE, 65% peak oxygen uptake; two 15 min bouts of cycling performed 20 min apart) and control trial (CON, seated and resting in a quiet room) at 80 min before the 75-g OGTT on separate days in a randomized, controlled crossover fashion. Carotid-femoral (aortic) and femoral-ankle (leg) pulse wave velocity, carotid augmentation index, brachial and ankle blood pressure, heart rate and blood glucose and insulin levels were measured before (baseline) and 30, 60 and 120 min after the 75-g OGTT. Leg pulse wave velocity, ankle systolic blood pressure and blood glucose levels increased from baseline after the 75-g OGTT in the CON trial, but not in the RE trial. The present findings indicate that acute repeated bouts of aerobic exercise before glucose ingestion suppress increases in leg arterial stiffness following glucose ingestion. Abbreviations: RE trial repeated bouts of aerobic exercise trial; CON trial control trial; BG blood glucose; VO_2peak peak oxygen uptake; PWV Pulse wave velocity; AIx carotid augmentation index; BP blood pressure; HR heart rate; CVs coefficients of variation; RPE Ratings of perceived exertion; SE standard error.

Acute Effects of Exercise Mode on Arterial Stiffness and Wave Reflection in Healthy Young Adults: A Systematic Review and Meta-Analysis

Background: This systematic review and meta-analysis quantified the effect of acute exercise mode on arterial stiffness and wave reflection measures including carotid-femoral pulse wave velocity (cf-PWV), augmentation index (AIx), and heart rate corrected AIx (AIx75). Methods: Using standardized terms, database searches from inception until 2017 identified 45 studies. Eligible studies included acute aerobic and/or resistance exercise in healthy adults, pre- and post-intervention measurements or change values, and described their study design. Data from included studies were analyzed and reported in accordance with the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. Meta-analytical data were reported via forest plots using absolute differences with 95% confidence intervals with the random effects model accounting for between-study heterogeneity. Reporting bias was assessed via funnel plots and, individual studies were evaluated for bias using the Cochrane Collaboration's tool for assessing risk of bias. A modified PEDro Scale was applied to appraise methodological concerns inherent to included studies. Results: Acute aerobic exercise failed to change cf-PWV (mean difference: 0.00 ms^-1 [95% confidence interval: -0.11, 0.11], p = 0.96), significantly reduced AIx (-4.54% [-7.05, -2.04], p = 0.0004) and significantly increased AIx75 (3.58% [0.56, 6.61], p = 0.02). Contrastingly, acute resistance exercise significantly increased cf-PWV (0.42 ms^-1 [0.17, 0.66], p = 0.0008), did not change AIx (1.63% [-3.83, 7.09], p = 0.56), and significantly increased AIx75 (15.02% [8.71, 21.33], p < 0.00001). Significant heterogeneity was evident within all comparisons except cf-PWV following resistance exercise, and several methodological concerns including low applicability of exercise protocols and lack of control intervention were identified. Conclusions: Distinct arterial stiffness and wave reflection responses were identified following acute exercise with overall increases in both cf-PWV and AIx75 following resistance exercise potentially arising fromcardiovascular and non-cardiovascular factors that likely differ from those following aerobic exercise. Future studies should address identified methodological limitations to enhance interpretation and applicability of arterial stiffness and wave reflection indices to exercise and health.

Carotid femoral pulse wave velocity in type 2 diabetes and hypertension: capturing arterial health effects of step counts

Objective:

Optimal medication use obscures the impact of physical activity on traditional cardiometabolic risk factors. We evaluated the relationship between step counts and carotid-femoral pulse wave velocity (cfPWV), a summative risk indicator, in patients with type 2 diabetes and/or hypertension.

Research design and methods:

Three hundred and sixty-nine participants were recruited (outpatient clinics; Montreal, Quebec; 2011–2015). Physical activity (pedometer/accelerometer), cfPWV (applanation tonometry), and risk factors (A1C, Homeostatic Model Assessment–Insulin Resistance, blood pressure, lipid profiles) were evaluated. Linear regression models were constructed to quantify the relationship of steps/day with cfPWV.

Results:

The study population comprised 191 patients with type 2 diabetes and hypertension, 39 with type 2 diabetes, and 139 with hypertension (mean ± SD: age 59.6 ± 11.2 years; BMI 31.3 ± 4.8 kg/m²; 54.2% women). Blood pressure (125/77 ± 15/9 mmHg), A1C (diabetes: 7.7 ± 1.3%; 61 mmol/mol), and low-density lipoprotein cholesterol (diabetes: 2.19 ± 0.8 mmol/l; without diabetes: 3.13 ± 1.1mmol/l) were close to target. Participants averaged 5125 ± 2722 steps/day. Mean cfPWV was 9.8 ± 2.2 m/s. Steps correlated with cfPWV, but not with other risk factors. A 1000 steps/day increment was associated with a 0.1 m/s cfPWV decrement across adjusted models and in subgroup analysis by diabetes status. In a model adjusted for age, sex, BMI, ethnicity, immigrant status, employment, education, diabetes, hypertension, medication classes, the mean cfPWV decrement was 0.11 m/s (95% confidence interval −0.2, −0.02).

Conclusions:

cfPWV is responsive to step counts in patients who are well controlled on cardioprotective medications. This ability to capture the ‘added value’ of physical activity supports the emerging role of cfPWV in arterial health monitoring.

A systematic review on the effect of acute aerobic exercise on arterial stiffness reveals a differential response in the upper and lower arterial segments

The objective of this systematic review was to provide insight into the controversy that still abounds as to the impact of acute aerobic exercise on immediate changes in arterial stiffness. Electronic databases were searched to identify articles assessing the effects of acute aerobic exercise on parameters of arterial stiffness. Eligible studies included arterial stiffness measurements before and after acute aerobic exercise in healthy human subjects. Forty-three studies were included. The effect of acute aerobic exercise on arterial stiffness was found to be dependent on the anatomical segment assessed, and on the timing of the measurement post-exercise. Arterial stiffness of the central and upper body peripheral arterial segments was found to be increased relative to resting values immediately post-exercise (0-5 min), whereas, thereafter (>5 min), decreased to a level at or below resting values. In the lower limbs, proximal to the primary working muscles, arterial stiffness decreased immediately post-exercise (0-5 min), which persisted into the recovery period post-exercise (>5 min). This systematic review reveals a differential response to acute exercise in the lower and upper/central arterial segments in healthy adult subjects. We further showed that the effect of acute aerobic exercise on arterial stiffness is dependent on the timing of the measurements post-exercise. Therefore, when assessing the overall impact of exercise on arterial stiffness, it is important to consider the arterial segment being analyzed and measurement time point, as failure to contextualize the measurement can lead to conflicting results and misleading clinical inferences.

Arterial hemodynamics are impaired at rest and following acute exercise in overweight young men

Higher body mass index (BMI) is associated with greater cardiovascular disease (CVD) risk, in part due to aortic stiffening assessed by carotid-femoral pulse wave velocity (cfPWV). Importantly, greater cardiorespiratory fitness (CRF; VO2peak) decreases CVD risk, and is associated with reductions in aortic stiffness. We tested the hypothesis that young adult overweight (OW, n=17) compared with healthy-weight (HW, n=17) men will have greater resting aortic stiffness, reduced CRF and an impaired post-exercise hemodynamic response. Resting cfPWV was greater in OW versus HW individuals (5.81 ± 0.13 vs 4.81 ± 0.12 m/sec, p<0.05). Relative CRF (VO2peak; mL/kg/min) was lower in OW compared with HW individuals (49.4 ± 1.3 vs 57.6 ± 1.0 mL/kg/min, p<0.05), and was inversely related with cfPWV ( p<0.05). However, CRF as absolute VO2peak (L/min) was not different between groups and there was no relation between cfPWV and absolute VO2peak (L/min), indicating reduced relative CRF in OW men is due to greater body mass. Following the maximal treadmill exercise test, cfPWV was greater in OW compared with HW subjects from rest to 60 minutes post-exercise ( p<0.05). Compared with HW, OW individuals had higher systolic blood pressure (main effect, p<0.05) and diastolic blood pressure was selectively increased for up to 60 minutes following exercise ( p<0.05). Overweight individuals had an attenuated post-exercise decrease in mean arterial pressure ( p<0.05). Collectively, these results indicate that young, apparently healthy, OW men have greater resting aortic stiffening and an impaired post-exercise hemodynamic response.

Carotid-Ventricular Coupling During Exercise: A Pilot Study

OBJECTIVES

To evaluate carotid elasticity and left ventricular elastance during a graded bicycle semisupine exercise test in patients with known or suspected coronary artery disease and compare them with a control group of healthy young volunteers.

METHODS

Thirty-six elderly patients and 18 young healthy volunteers were recruited. The right carotid diameter was estimated by an automatic system applied to B-mode sonographic sequences, central mean blood and pulse pressures by radial artery tonometry, and cardiac volumes by 2-dimensional transthoracic echocardiography; from these direct measurements, the carotid cross-sectional distensibility coefficient and left ventricular elastance index were obtained. Analyses were performed at rest, at peak stress, and during the recovery phase.

RESULTS

The elderly patients included 20 men (mean age ± SD, 61 ± 8 years); the volunteers included 9 men (mean age, 34 ± 3 years). The mean blood pressure (at rest: patients, 97 ± 7 mm Hg; controls, 93 ± 9 mm Hg; not significant) increased similarly in both groups during exercise and decreased during the recovery phase. The diameter was higher in patients than controls (7.5 ± 1.1 versus 6.2 ± 0.5 mm) and increased significantly with exercise only in the latter group (at peak: 6.5 ± 0.6 mm; P < .05). The distensibility coefficient and elastance index were lower in patients than controls during the test phases [at rest: 24.5 ± 10.2 versus 60.8 ± 21.3 × 10(-3)/kPa and 3.6 ± 1.4 versus 1.6 ± 0.8 mm Hg/(mL/m(2))] and mostly changed in the controls, showing a decreased distensibility coefficient (peak: 40.6 ± 15.1 × 10(-3)/kPa) and an increased elastance index [peak: 5.9 ± 2.8 mm Hg/(mL/m(2))].

CONCLUSIONS

In older patients with multiple cardiovascular risk factors or established coronary artery disease, an abnormal carotid-ventricular adaptation to exercise was observed when compared to young healthy individuals.

Feasibility of a clinical trial to assess the effect of dietary calcium v. supplemental calcium on vascular and bone markers in healthy postmenopausal women

Whether supplemental Ca has similar effects to dietary Ca on vascular and bone markers is unknown. The present trial investigated the feasibility of applying dietary and supplemental interventions in a randomised-controlled trial (RCT) aiming to estimate the effect of supplemental Ca as compared with dietary Ca on vascular and bone markers in postmenopausal women. In total, thirteen participants were randomised to a Ca supplement group (CaSuppl) (750 mg Ca from CaCO3+450 mg Ca from food+20 µg vitamin D supplement) or a Ca diet group (CaDiet) (1200 mg Ca from food+10 µg vitamin D supplement). Participants were instructed on Ca consumption targets at baseline. Monthly telephone follow-ups were conducted to assess adherence to interventions (±20 % of target total Ca) using the multiple-pass 24-h recall method and reported pill count. Measurements of arterial stiffness, peripheral blood pressure and body composition were performed at baseline and after 6 and 12 months in all participants who completed the trial (n 9). Blood and serum biomarkers were measured at baseline and at 12 months. Both groups were compliant to trial interventions (±20 % of target total Ca intake; pill count ≥80 %). CaSuppl participants maintained a significantly lower average dietary Ca intake compared with CaDiet participants throughout the trial (453 (sd 187) mg/d v. 1241 (sd 319) mg/d; P<0·001). There were no significant differences in selected vascular outcomes between intervention groups over time. Our pilot trial demonstrated the feasibility of conducting a large-scale RCT to estimate the differential effects of supplemental and dietary Ca on vascular and bone health markers in healthy postmenopausal women.

Acute Effects of Exercise on Blood Pressure: A Meta-Analytic Investigation

Hypertension affects 25% of the world's population and is considered a risk factor for cardiovascular disorders and other diseases. The aim of this study was to examine the evidence regarding the acute effect of exercise on blood pressure (BP) using meta-analytic measures. Sixty-five studies were compared using effect sizes (ES), and heterogeneity and Z tests to determine whether the ES were different from zero. The mean corrected global ES for exercise conditions were -0.56 (-4.80 mmHg) for systolic BP (sBP) and -0.44 (-3.19 mmHg) for diastolic BP (dBP; z ≠ 0 for all; p < 0.05). The reduction in BP was significant regardless of the participant's initial BP level, gender, physical activity level, antihypertensive drug intake, type of BP measurement, time of day in which the BP was measured, type of exercise performed, and exercise training program (p < 0.05 for all). ANOVA tests revealed that BP reductions were greater if participants were males, not receiving antihypertensive medication, physically active, and if the exercise performed was jogging. A significant inverse correlation was found between age and BP ES, body mass index (BMI) and sBP ES, duration of the exercise's session and sBP ES, and between the number of sets performed in the resistance exercise program and sBP ES (p < 0.05). Regardless of the characteristics of the participants and exercise, there was a reduction in BP in the hours following an exercise session. However, the hypotensive effect was greater when the exercise was performed as a preventive strategy in those physically active and without antihypertensive medication.

Effects on carotid-femoral pulse wave velocity 24 h post exercise in young healthy adults

Arterial stiffness, often measured by carotid-femoral pulse wave velocity (cfPWV), is a subclinical marker of cardiovascular disease that is known to be reduced by exercise training. Exercise is also known to have acute vascular effects, yet it is unclear whether exercise 24 h before cfPWV testing influences this outcome. Thirty healthy, young adults completed a supervised, 30-min bout of moderate-to-vigorous intensity treadmill running. cfPWV, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured both before (after 48 h of abstaining from exercise) and 24 h after (with no additional exercise) the exercise session. From pre-exercise to 24 h post exercise, cfPWV decreased from 6.05±0.82 to 5.84±0.87 m s(-1) (P=0.02), SBP from 119.7±13.8 to 116.8±11.4 mm Hg (P=0.03) and DBP from 65.1±5.7 to 63.2±5.4 mm Hg (P=0.02), with no significant changes in HR. cfPWV was positively correlated with SBP pre-exercise (r=0.54, P<0.01) and post exercise (r=0.53, P<0.01). Changes in blood pressure explained 4-5% of the variability in cfPWV change; adjustments slightly attenuated the 24-h effects of exercise on cfPWV. Some evidence of gender differences was observed with higher cfPWV in males across assessments (P<0.05) and statistically significant reductions in cfPWV in males (-0.36±0.54 m s(-1) (P=0.02)) but not in females (-0.07±0.31 m s(-1) (P=0.41)). In conclusion, cfPWV decreased 24 h after an exercise bout, suggesting that exercise completed in the past 24 h should be considered before cfPWV testing.

Endothelial function does not improve with high-intensity continuous exercise training in SHR: implications of eNOS uncoupling

Exercise training is a well-recognized way to improve vascular endothelial function by increasing nitric oxide (NO) bioavailability. However, in hypertensive subjects, unlike low- and moderate-intensity exercise training, the beneficial effects of continuous high-intensity exercise on endothelial function are not clear, and the underlying mechanisms remain unknown. The aim of this study was to investigate the impact of high-intensity exercise on vascular function, especially on the NO pathway, in spontaneous hypertensive rats (SHR). These effects were studied on WKY, sedentary SHR and SHR that exercised at moderate (SHR-MOD) and high intensity (SHR-HI) on a treadmill (1 h per day; 5 days per week for 6 weeks at 55% and 80% of their maximal aerobic velocity, respectively). Endothelial function and specific NO contributions to acetylcholine-mediated relaxation were evaluated by measuring the aortic ring isometric forces. Endothelial nitric oxide synthase (eNOS) expression and phosphorylation (ser1177) were evaluated by western blotting. The total aortic and eNOS-dependent reactive oxygen species (ROS) production was assessed using electron paramagnetic resonance in aortic tissue. Although the aortas of SHR-HI had increased eNOS levels without alteration of eNOS phosphorylation, high-intensity exercise had no beneficial effect on endothelium-dependent vasorelaxation, unlike moderate exercise. This result was associated with increased eNOS-dependent ROS production in the aortas of SHR-HI. Notably, the use of the recoupling agent BH4 or a thiol-reducing agent blunted eNOS-dependent ROS production in the aortas of SHR-HI. In conclusion, the lack of a positive effect of high-intensity exercise on endothelial function in SHR was mainly explained by redox-dependent eNOS uncoupling, resulting in a switch from NO to O2(-) generation.

Vigorous physical activity and carotid distensibility in young and mid-aged adults

Although physical activity (PA) improves arterial distensibility, it is unclear which type of activity is most beneficial. We aimed to examine the association of different types of PA with carotid distensibility (CD) and the mechanisms involved. Data included 4503 Australians and Finns aged 26-45 years. Physical activity was measured by pedometers and was self-reported. CD was measured using ultrasound. Other measurements included resting heart rate (RHR), cardiorespiratory fitness (CRF), blood pressure, biomarkers and anthropometry. Steps/day were correlated with RHR (Australian men r = -0.10, women r = - 0.14; Finnish men r = -0.15, women r = -0.11; P<0.01), CRF and biochemical markers, but not with CD. Self-reported vigorous leisure-time activity was more strongly correlated with RHR (Australian men r = -0.23, women r = -0.19; Finnish men r = -0.20, women r = -0.13; P < 0.001) and CRF, and was correlated with CD (Australian men r = 0.07; Finnish men r = 0.07, women r = 0.08; P < 0.05). This relationship of vigorous leisure-time activity with CD was mediated by RHR independently of potential confounders. In summary, vigorous leisure-time PA but not total or less intensive PA was associated with arterial distensibility in young to mid-aged adults. Promotion of vigorous PA is therefore recommended among this population. RHR was a key intermediary factor explaining the relationship between vigorous PA and arterial distensibility.

Accurate quantitative measurements of brachial artery cross-sectional vascular area and vascular volume elastic modulus using automated oscillometric measurements: comparison with brachial artery ultrasound

Increasing vascular diameter and attenuated vascular elasticity may be reliable markers for atherosclerotic risk assessment. However, previous measurements have been complex, operator-dependent or invasive. Recently, we developed a new automated oscillometric method to measure a brachial artery's estimated area (eA) and volume elastic modulus (V_E). The aim of this study was to investigate the reliability of new automated oscillometric measurement of eA and V_E. Rest eA and V_E were measured using the recently developed automated detector with the oscillometric method. eA was estimated using pressure/volume curves and V_E was defined as follows (V_E=Δ pressure/ (100 × Δ area/area) mm Hg/%). Sixteen volunteers (age 35.2±13.1 years) underwent the oscillometric measurements and brachial ultrasound at rest and under nitroglycerin (NTG) administration. Oscillometric measurement was performed twice on different days. The rest eA correlated with ultrasound-measured brachial artery area (r=0.77, P<0.001). Rest eA and V_E measurement showed good reproducibility (eA: intraclass correlation coefficient (ICC)=0.88, V_E: ICC=0.78). Under NTG stress, eA was significantly increased (12.3±3.0 vs. 17.1±4.6 mm², P<0.001), and this was similar to the case with ultrasound evaluation (4.46±0.72 vs. 4.73±0.75 mm, P<0.001). V_E was also decreased (0.81±0.16 vs. 0.65±0.11 mm Hg/%, P<0.001) after NTG. Cross-sectional vascular area calculated using this automated oscillometric measurement correlated with ultrasound measurement and showed good reproducibility. Therefore, this is a reliable approach and this modality may have practical application to automatically assess muscular artery diameter and elasticity in clinical or epidemiological settings.