Reliability of arterial stiffness indices at rest and following a single bout of moderate-intensity exercise in older adults

Influence of cardiorespiratory fitness and body composition on resting and post-exercise indices of vascular health in young adults

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals. This study aimed to compare flow mediated dilation (FMD) and vascular augmentation index (AIx75) between young adults with low, moderate, and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise. Forty-three participants (22 men; 21 women) between 18 and 29 years of age completed the study. Participants were classified into low, moderate, and high health-related cardiorespiratory fitness groups according to age- and sex-based relative maximal oxygen consumption (V ˙ O2 max) percentile rankings. FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70% V ˙ O2 max. A significant interaction (p ​= ​0.047; ηp2 ​= ​0.142) was observed, with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline ([6.7% ​± ​3.1%] vs. [8.5% ​± ​2.8%], p ​= ​0.028; d ​= ​0.598). We found a significant main effect of group for AIx75 (p ​= ​0.023; ηp2 ​= ​0.168), with the high fitness group exhibiting lower AIx75 compared to low fitness group ([-10% ​± ​10%] vs. [2% ​± ​10%], respectively, p ​= ​0.019; g ​= ​1.07). This was eliminated after covarying for body fat percentage (p ​= ​0.489). Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness, but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.

Mixed circuit training acutely reduces arterial stiffness in patients with chronic stroke: a crossover randomized controlled trial

PURPOSE

Investigate whether a single bout of mixed circuit training (MCT) can elicit changes in arterial stiffness in patients with chronic stroke. Second, to assess the between-day reproducibility of post-MCT arterial stiffness measurements.

METHODS

Seven participants (58 ± 12 years) performed a non-exercise control session (CTL) and two bouts of MCT on separate days in a randomized counterbalanced order. The MCT involved 3 sets of 15 repetition maximum for 10 exercises, with each set separated by 45-s of walking. Brachial-radial pulse wave velocity (br-PWV), radial artery compliance (AC) and reflection index (RI_1,2) were assessed 10 min before and 60 min after CTL and MCT. Ambulatory arterial stiffness index (AASI) was calculated from 24-h recovery ambulatory blood pressure monitoring.

RESULTS

Compared to CTL, after 60 min of recovery from the 1st and 2nd bouts of MCT, lower values were observed for br-PWV (mean diff = - 3.9 and - 3.7 m/s, respectively, P < 0.01; ICC_2,1 = 0.75) and RI_1,2 (mean diff = - 16.1 and - 16.0%, respectively, P < 0.05; ICC_2,1 = 0.83) concomitant with higher AC (mean diff = 1.2 and 1.0 × 10^-6 cm⁵/dyna, respectively, P < 0.01; ICC_2,1 = 0.40). The 24-h AASI was reduced after bouts of MCT vs. CTL (1st and 2nd bouts of MCT vs. CTL: mean diff = - 0.32 and - 0.29 units, respectively, P < 0.001; ICC_2,1 = 0.64).

CONCLUSION

A single bout of MCT reduces arterial stiffness during laboratory (60 min) and ambulatory (24 h) recovery phases in patients with chronic stroke with moderate-to-high reproducibility.

TRIAL REGISTRATION

Ensaiosclinicos.gov.br identifier RBR-5dn5zd.

Effects of Acute Interval Exercise on Arterial Stiffness and Cardiovascular Autonomic Regulatory Responses: A Narrative Review of Potential Impacts of Aging

The physiological changes associated with aging deleteriously impact cardiovascular function and regulation and therefore increase the risk of developing cardiovascular disease. There is substantial evidence that changes in the autonomic nervous system and arterial stiffness play an important role in the development of cardiovascular disease during the aging process. Exercise is known to be effective in improving autonomic regulation and arterial vascular compliance, but differences in the type and intensity of exercise can have varying degrees of impact on vascular regulatory responses and autonomic function. There is still little evidence on whether there are differences in the response of exercise interventions to cardiovascular modulatory effects across the lifespan. In addition, acute interval exercise challenges can improve autonomic modulation, although the results of interval exercise on autonomic physiological parameters vary. Therefore, this narrative review focuses on evaluating the effects of acute interval exercise on blood pressure regulation and autonomic responses and also incorporates studies investigating different age groups to evaluate the effects of acute interval exercise on the autonomic nervous system. Herein we also summarize existing literature examining the acute cardiovascular responses to varied modes of interval exercise, as well as to further compare the benefits of interval exercise with other types of exercise on autonomic regulation and arterial stiffness. After reviewing the existing literature, it has been shown that with advancing age, changes in the autonomic nervous activity of interval exercise result in significant impacts on the cardiovascular system. We document that with advancing age, changes in the autonomic nerves lead to aging of the nervous system, thereby affecting the regulation of blood pressure. According to the limited literature, interval exercise is more effective in attenuating arterial stiffness than continuous exercise, but the difference in exercise benefits may depend on the training mode, intensity, duration of exercise, and the age of participants. Therefore, the benefits of interval exercise on autonomic and arterial stiffness improvement still warrant investigation, particularly the impact of age, in future research.

Cerebrovascular function and its association with systemic artery function and stiffness in older adults with and without mild cognitive impairment

PURPOSE

Our aim was to compare cerebrovascular and systemic vascular function between older adults with and without mild cognitive impairment (MCI), and to determine which measures of vascular function best predict the presence of MCI.

METHODS

In 41 adults with MCI and 33 adults without MCI (control) we compared middle cerebral artery velocity (MCAv) and cerebrovascular pulsatility index (PI) at rest, cerebrovascular reactivity to CO₂, and responsiveness to changes in blood pressure (%∆MCAv/%∆MAP). Systemic vascular function was assessed by flow-mediated dilation (FMD) and stiffness by pulse wave velocity (PWV).

RESULTS

Cerebrovascular PI was higher in MCI compared with control (mean ± SD: 1.17 ± 0.27 vs. 1.04 ± 0.21), and MCI exhibited a lower %∆MCAv/%∆MAP (1.26 ± 0.44 vs. 1.50 ± 0.55%). Absolute (p = 0.76) and relative cerebrovascular reactivity to CO₂ (p = 0.34) was similar between MCI and control. When age was included as a covariate the significant difference in cerebral PI between groups was lost. PWV was higher (13.2 ± 2.2 vs. 11.3 ± 2.5 m s^-1) and FMD% (4.41 ± 1.70 vs. 5.43 ± 2.15%) was lower in MCI compared with control. FMD% was positively associated with PI across the cohort. Logistic regression analysis indicated that FMD and PWV significantly discriminated between MCI and controls, independent of age, whereas the inclusion of cerebrovascular measures did not improve the predictive accuracy of the model.

CONCLUSION

These findings raise the possibility that early changes in systemic vascular stiffness and endothelial function may contribute to altered cerebrovascular haemodynamics and impaired cognitive function, and present potential targets for prevention and treatment strategies in people with MCI.

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.

Aortic and Systemic Arterial Stiffness Responses to Acute Exercise in Patients With Small Abdominal Aortic Aneurysms

OBJECTIVE/BACKGROUND

Elevated arterial stiffness is a characteristic of abdominal aortic aneurysm (AAA), and is associated with AAA growth and cardiovascular mortality. A bout of exercise transiently reduces aortic and systemic arterial stiffness in healthy adults. Whether the same response occurs in patients with AAA is unknown. The effect of moderate- and higher intensity exercise on arterial stiffness was assessed in patients with AAA and healthy adults.

METHODS

Twenty-two men with small diameter AAAs (36 ± 5 mm; mean age 74 ± 6 years) and 22 healthy adults (mean age 72 ± 5 years) were included. Aortic stiffness was measured using carotid to femoral pulse wave velocity (PWV), and systemic arterial stiffness was estimated from the wave reflection magnitude (RM) and augmentation index (Alx75). Measurements were performed at rest and during 90 min of recovery following three separate test sessions in a randomised order: (i) moderate intensity continuous exercise; (ii) higher intensity interval exercise; or (iii) seated rest.

RESULTS

At rest, PWV was higher in patients with AAA than in healthy adults (p < .001), while AIx75 and RM were similar between groups. No differences were observed between AAA patients and healthy adults in post-exercise aortic and systemic arterial stiffness after either exercise protocol. When assessed as the change from baseline (delta, Δ), post-exercise ΔAIx75 was not different to the seated rest protocol. Conversely, post-exercise ΔPWV and ΔRM were both lower at all time points than seated rest (p < .001). ΔPWV was lower immediately after higher intensity than after moderate intensity exercise (p = .015).

CONCLUSION

High resting aortic stiffness in patients with AAA is not exacerbated after exercise. There was a similar post-exercise attenuation in arterial stiffness between patients with AAA and healthy adults compared with seated rest. This effect was most pronounced following higher intensity interval exercise, suggesting that this form of exercise may be a safe and effective adjunctive therapy for patients with small AAAs.