Aerobic exercise and strength training effects on cardiovascular sympathetic function in healthy adults: a randomized controlled trial

Blood pressure variability is altered in secondary progressive multiple sclerosis but not in patients with a clinically isolated syndrome

OBJECTIVES

To investigate differences in beat-to-beat systolic blood pressure variability (SBPV) in people with secondary progressive MS (pwSPMS), clinically isolated syndrome (pwCIS) and healthy controls (HC).

METHODS

This retrospective case-control study included 46 pwSPMS, 46 pwCIS and 44 HC. A semi-automated software made with MATLAB R2019b (The MathWorks, Inc.) was used for the evaluation of SBPV. The frequency domain characteristics observed were the power spectrum in the LF and HF bands and the LF/HF ratio. Data is expressed in absolute power (mmHg²) of LF and HF and ratio (LF/HF) during both supine and tilt-up phases of testing.

RESULTS

There were no significant differences in mean systolic (sBP) or diastolic blood pressure (dBP) values during supine and tilt-up phases of testing between groups. During the supine phase of testing LF and LF/HF were significantly lower in the SPMS group (4.17±5.38 and 3.52±2.34, respectively) compared to the CIS (5.42±3.59, p = 0.015 and 5.92±4.63, p = 0.029, respectively) and HC group (6.03±4.55, p = 0.011 and 6.52 ± 5.09, p = 0.010, respectively), while during the tilt-up phase, LF was significantly lower compared to both the CIS and HC group, and HF was significantly lower only compared to the CIS group.

CONCLUSION

SBPV is altered in pwSPMS compared to pwCIS and normal controls. Further research in the field of MS related dysautonomia is warranted not only because of its relevance to comorbidities and MS symptoms, but also because of its likely involvement in the pathophysiology of MS.

Effects of a single beach tennis session on short-term blood pressure variability in individuals with hypertension: a randomized crossover trial

Despite the importance of blood pressure (BP) variability to estimate cardiovascular risk in patients with hypertension, not all exercise modalities can reduce short-term BP variability, and no studies have measured the acute effects of recreational sports on short-term BP variability. We investigated the acute effects of a single beach tennis (BT) session on short-term BP variability in individuals with hypertension. Twenty-two participants took part in this randomized clinical trial. They were randomly allocated to a BT session and a nonexercise control session (Con). BT and Con sessions lasted 45 min. Office BP and heart rate were measured throughout the experimental sessions to calculate rate-pressure products and estimate the cardiovascular demand of BT. To determine short-term BP variability after BT and Con sessions, average real variability (ARV) of systolic BP and diastolic BP was assessed over 24 h using ambulatory BP monitoring. Compared with Con, there were lower 24-h (Δ, -0.9 ± 0.4 mmHg; P = 0.049) and daytime (Δ, -1.4 ± 0.5 mmHg; P = 0.004) ARV of diastolic BP after BT. There were no significant differences in ARV of systolic BP between Con and BT. There was a higher rate-pressure product found during BT (P < 0.001). However, after the experimental sessions, there was no significant difference between BT and Con for the rate-pressure product under ambulatory conditions. In conclusion, a single BT session reduced daytime and 24-h diastolic BP variability in adults with hypertension. Trial registration: ClinicalTrials.gov, NCT03909308.

Heart Rate Responses and Cardiovascular Adaptations to Resistance Training Programs Differing in Set Configuration: A Randomized Controlled Trial

Purpose: This study explored the changes in blood pressure and cardiac autonomic modulation after training programs differin in set configuration. Methods: Thirty-nine individuals were randomly assigned to a traditional, rest-redistribution, or control group. Throughout five weeks, the traditional and rest-redistribution groups performed 10 sessions of four exercises with the same load, number of repetitions, and total rest time, but with different inter-set rest duration and frequency (traditional group: 4 sets of 8 repetitions, 10 repetition maximum load, 5 min rest between sets and exercises; rest-redistribution group: 16 sets of 2 repetitions, 1 min rest between sets, 5 min rest between exercises). Heart rate and heart rate recovery were recorded during each training session, and heart rate variability, baroreflex sensitivity and effectiveness, blood pressure, and blood pressure variability were evaluated at rest bedore and after the interventions. Results: During the sessions, traditional sets entailed greater peak heart rate compared to rest-redistribution (P = .018) but mean heart rate, minimum heart rate, and heart rate recovery were similar between training programs (P >.05). Baroreflex effectiveness was reduced after the traditional intervention (P = .013). No changes were detected for the rest of the cardiovascular variables obtained at rest after intervention (P > .05). Conclusions: Despite some differences in heart rate response during exercise, neither traditional nor rest-redistribution resistance training protocols produced changes in cardiac autonomic modulation, sympathetic vasomotor tone, and cardiac baroreflex sensitivity of young healthy active individuals. However, traditional sets affected the baroreflex effectiveness.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

The importance of physical activity and cardiorespiratory fitness for patients with heart failure

The present review highlights current research on the importance of PA and fitness for patients with heart failure and recommendations with respect to heart failure phenotypes and special populations. Furthermore, the evidence for various exercise types and intensities/doses as an "exercise prescription", are discussed. The strong association between heart failure and traditional risk factors, physical inactivity and low fitness, underlines the importance of regular PA and exercise for prevention and treatment of heart failure. This is illustrated by cardiac stiffness which typically accelerates in middle-life and could be reversed by aerobic exercise. In patients with HFpEF, regular PA counteracts many of the changes observed, both metabolic and functional. Indeed, exercise-based cardiac rehabilitation has received a class 1A recommendation in current guidelines [1], in order to improve functional capacity, quality of life and lower the risk of rehospitalization. An individually tailored plan based on risk stratification, clinical assessment and cardiopulmonary exercise testing is encouraged before initiation of exercise training in patients with heart failure. In general, a combination of aerobic exercise and resistance training protocols is recommended (Table 1) [2], preferably throughout life. More studies are needed, regarding the role of PA and exercise in specific populations, such as frail patients with heart failure.

Structured, multifactorial randomised controlled intervention to investigate physical activity levels, body composition and diet in obese and overweight adolescents

INTRODUCTION

There has been a steep increase in the prevalence of adolescent overweight and obesity globally and in India, demonstrating that present prevention strategies are insufficient. Available evidence suggests that multifactorial interventions may improve short-term physical activity (PA), nutrition and psychological behaviour of overweight and obese adolescents but long-term follow-ups and strategies are needed. This study will investigate the effects of a structured multifactorial (school-based and family-based) intervention on adolescent obesity, compared with a single or no intervention.

METHODS AND ANALYSIS

A pragmatic, clustered randomised controlled trial with 12 weeks of interventions and 3-month, 6-month and 12-month follow-ups will be conducted at multiple participating schools in Karnataka, India. The participants will be overweight and obese male and female adolescents aged 11-16 years and will be randomly assigned by school into three groups: group A (multifactorial intervention, exercise and dietary advice); group B (exercise only); and group C (controls, no interventions). Primary outcome measures are the level of PA and body composition. Secondary outcomes are dietary change, behaviour change, food behaviours, cardiovascular and muscular fitness, quality of life, parental behaviours (physical and mental) and family functioning. Positive intervention results may reduce obesity in adolescents and promote a healthier lifestyle for students and families. A larger, culturally diverse population can benefit from a similar methodology.

ETHICS AND DISSEMINATION

The study has been approved by the Institutional Research and Ethics Committee (IEC 536-2018), Kasturba Hospital, Manipal, Udupi District, Karnataka, India. A written and verbal informed consent (supplemental material) will be provided to the participants prior to participation. On completion of the trial, the results can be communicated to adolescents and their parents on request, and will be published at national and international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

CTRI/2019/04/018834.

Acute and chronic effects of combined exercise on ambulatory blood pressure and its variability in hypertensive postmenopausal women

The aim of this study was to investigate the acute and chronic effects, and their correlation, after combined aerobic and resistance exercises in blood pressure (BP) and its variability (BPV) in hypertensive postmenopausal women. Fourteen hypertensive postmenopausal women monitored BP at rest and during 24 h by ambulatory BP monitoring in a control day without exercise performance a pretraining (baseline), after an acute exercise session (acute), and after a chronic exercise training for 10 weeks (chronic). After exercise training, systolic BP (SBP, Δ = -150 mmHg.24 h), diastolic BP (DBP, Δ = -96 mmHg.24 h), and mean BP (MBP, Δ = -95 mmHg.24 h) area under the curve were smaller than baseline measurements (P < 0.05) with no difference between acute and baseline measurements. The SBP (ΔSD₂₄ = -2, ΔSD_dn = -1.7, and ΔARV₂₄ = -1.9 mmHg), DBP (ΔSD₂₄ = -0.9, ΔSD_dn = -0.8, and ΔARV₂₄ = -0.9 mmHg), and MBP (ΔSD₂₄ = -1.5, ΔSD_dn = -1.3, and ΔARV₂₄ = -1.2 mmHg) variability reduced in acute session in relation to baseline, with no chronic effects. There are moderate correlations between acute and chronic responses in wake SBP, sleep DBP, and SD₂₄. In conclusion, combined exercise reduces ambulatory BP chronically but not acutely. In contrast, BPV decreases after an acute session but not chronically. Awake SBP, sleep DBP, and SD₂₄indices are promising candidates to predict individual cardiovascular responses to exercise.

Isoflavone Supplementation Does Not Potentiate the Effect of Combined Exercise Training on Resting and Ambulatory Blood Pressure in Non-Obese Postmenopausal Women: A Randomized Double-Blind Controlled Trial-A Pilot Study

Physical exercise and isoflavone supplementation are potential strategies to prevent and treat cardiovascular diseases in postmenopausal women. The aim of this study was to investigate whether there are additive effects of isoflavone supplementation when associated with combined aerobic and resistance exercise on resting and ambulatory blood pressure monitoring (ABPM) and in blood pressure variability (BPV). Thirty-one non-obese postmenopausal women were randomly allocated into two groups: placebo and exercise (Placebo n = 19); and isoflavone supplementation (100 mg/day) and exercise (isoflavone n = 19). ABPM and BPV were evaluated before and after 10 weeks of moderate combined (aerobic and resistance) exercise training. Generalized Estimating Equation (GEE) with Bonferroni correction and intention-to-treat analysis was used to compare the effects of interventions on resting BP, ABPM and BPV. Combined exercise training decreased resting systolic (SBP) and diastolic blood pressure (DBP) and reduced 24 h and awake ambulatory SBP, DBP and mean blood pressure over time, with no additional effects of isoflavone supplementation. No changes were observed in sleep period, or in BPV indexes (Standard Deviation of 24 h (SD), daytime and nighttime interval (SDdn) and average real variability (ARV) in both groups. We conclude that isoflavone supplementation does not potentiate the effects of combined training on resting and ambulatorial systolic and diastolic blood pressure in non-obese postmenopausal women.

Elevated resting heart rate in adolescent men and risk of heart failure and cardiomyopathy

Aims

This study aims to investigate the association of resting heart rate (RHR) measured in late adolescence with long‐term risk of cause‐specific heart failure (HF) and subtypes of cardiomyopathy (CM), with special attention to cardiorespiratory fitness.

Methods and results

We performed a nation‐wide, register‐based cohort study of all Swedish men enrolled for conscription in 1968–2005 (n = 1 008 363; mean age = 18.3 years). RHR and arterial blood pressure were measured together with anthropometrics as part of the enlistment protocol. HF and its concomitant diagnoses, as well as all CM diagnoses, were collected from the national inpatient, outpatient, and cause of death registries. Risk estimates were calculated by Cox‐proportional hazards models while adjusting for potential confounders. During follow‐up, there were 8400 cases of first hospitalization for HF and 3377 for CM. Comparing the first and fifth quintiles of the RHR distribution, the hazard ratio (HR) for HF associated with coronary heart disease, diabetes, or hypertension was 1.25 [95% confidence interval (CI) = 1.13–1.38] after adjustment for body mass index, blood pressure, and cardiorespiratory fitness. The corresponding HR was 1.43 (CI = 1.08–1.90) for HF associated with CM and 1.34 (CI = 1.16–1.54) for HF without concomitant diagnosis. There was an association between RHR and dilated CM [HR = 1.47 (CI = 1.27–1.71)] but not hypertrophic, alcohol/drug‐induced, or other cardiomyopathies.

Conclusions

Adolescent RHR is associated with future risk of HF, regardless of associated aetiological condition. The association was strongest for HF associated with CM, driven by the association with dilated CM. These findings indicate a causal pathway between elevated RHR and myocardial dysfunction that warrants further investigation.

Associations Between Colonic Motor Patterns and Autonomic Nervous System Activity Assessed by High-Resolution Manometry and Concurrent Heart Rate Variability

Abnormal colonic motility may be associated with dysfunction of the autonomic nervous system (ANS). Our aim was to evaluate if associations between colonic motor patterns and autonomic neural activity could be demonstrated by assessing changes in heart rate variability (HRV) in healthy volunteers. A total of 145 colonic motor patterns were assessed in 11 healthy volunteers by High-Resolution Colonic Manometry (HRCM) using an 84-channel water-perfused catheter. Motor patterns were evoked by balloon distention, a meal and luminal bisacodyl. The electrocardiogram (ECG) and cardiac impedance were assessed during colonic manometry. Respiratory sinus arrhythmia (RSA) and root mean square of successive differences of beat-to-beat intervals (RMSSD) served as measures of parasympathetic reactivity while the Baevsky's Stress Index (SI) and the pre-ejection period (PEP) were used as measures of sympathetic reactivity. Taking all motor patterns into account, our data show that colonic motor patterns are accompanied by increased parasympathetic activity and decreased sympathetic activity that may occur without eliciting a significant change in heart rate. Motor Complexes (more than one motor pattern occurring in close proximity), High-Amplitude Propagating Pressure Waves followed by Simultaneous Pressure Waves (HAPW-SPWs) and HAPWs without SPWs are all associated with an increase in RSA and a decrease in SI. Hence RSA and SI may best reflect autonomic activity in the colon during these motor patterns as compared to RMSSD and PEP. SI and PEP do not measure identical sympathetic reactivity. The SPW, which is a very low amplitude pressure wave, did not significantly change the autonomic measures employed here. In conclusion, colonic motor patterns are associated with activity in the ANS which is reflected in autonomic measures of heart rate variability. These autonomic measures may serve as proxies for autonomic neural dysfunction in patients with colonic dysmotility.

Enhancement of hypothalamic-pituitary activity in male athletes: evidence of a novel hormonal mechanism of physical conditioning

BACKGROUND

Exercise is known to induce multiple beneficial conditioning processes. Conversely, although exercise may generate several hormonal effects, an intrinsic hormonal conditioning process has not been reported. In the Endocrine and Metabolic Responses on Overtraining Syndrome (EROS) study, we observed inherent and independent conditioning processes of the hypothalamic-pituitary axes in athletes. Our objective is to describe the theory of the novel hormonal conditioning mechanism using the findings from the EROS study.

METHODS

In this cross-sectional study, we selected 25 healthy athletes (ATL) and 12 non-physically active healthy controls (NPAC), 18-50 years old, males, with BMI 20-30 kg/m², with similar baseline characteristics, who underwent gold-standard exercise-independent tests: cosyntropin stimulation test (CST) and insulin tolerance test (ITT), to evaluate cortisol response to CST, and ACTH, cortisol, GH, and prolactin responses to an ITT.

RESULTS

Responses to ITT were significantly earlier and higher in ATL than NPAC for cortisol [Mean ± SD: 21.7 ± 3.1 vs 16.9 ± 4.1 μg/dL; p < 0.001], GH [Median (95% CI): 12.73 (1.1-38.1) vs 4.80 (0.33-27.36) μg/L; p = 0.015], and prolactin [24.3 (10.5-67.45) vs 10.50 (6.21-43.44) ng/mL; p = 0.002]. Cortisol response to CST was similar between ATL and NPAC. During ITT, cortisol, GH, and ACTH mean increase in ATL were 52.2, 265.2, and 18.6% higher than NPAC, respectively. Prolactin response was absent in NPAC, while present in ATL.

CONCLUSIONS

We found sufficient evidence to propose the existence of a diffuse enhancement of the hypothalamic-pituitary activity in athletes, not restricted to any axis, showing an intrinsic and independent process of "hormonal conditioning" in athletes, similar to those observed in the cardiovascular and neuromuscular systems. This novel conditioning process may be the missing link for understanding the improved responses observed in athletes to harmful situations, traumas, infections, inflammations, and psychiatric conditions.

Physical activity moderates the effects of daily psychosocial stressors on ambulatory blood pressure

OBJECTIVE

Previous literature has shown an inconsistent relationship between physical activity and stressor-evoked blood pressure reactivity. Use of ecological momentary assessment (EMA) may facilitate detecting such a relationship. In this study, the moderating effects of regular physical activity on the magnitude of ambulatory blood pressure (ABP) responses to psychosocial stressors experienced in daily life were examined.

METHOD

Four hundred seventy-seven healthy working adults (ages 30-54) provided ABP readings and recorded their daily experiences, using electronic diaries (ED), over 4 monitoring days. Measures of momentary Task Strain (high demand, low control) and Social Conflict (rating of recent social interaction quality) were used as indices of stressor exposure, and an accelerometry device was used to create 2 indices of physical activity: weekly average and recent (30 min prior to each ED interview). Multilevel models were used to examine the moderating between- and within-person effects of physical activity on ABP fluctuations corresponding with the momentary psychosocial stressors.

RESULTS

Weekly physical activity moderated the effects of ABP responses to Task Strain (systolic blood pressure [SBP]: p = .033; diastolic blood pressure [DBP]: p = .028) and Social Conflict (DBP: p = .020), with significant increases in SBP and DBP shown for less physically active individuals but not for more physically active individuals. Similarly, recent physical activity moderated within-person DBP responses to Task Strain (p = .025), with greater DBP increases following less active periods.

CONCLUSION

Our results demonstrate that weekly and recent physical activity may moderate the effects of ABP responses to daily psychosocial stress. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Different exercise modalities exert opposite acute effects on short-term blood pressure variability in male patients with hypertension

BACKGROUND

The aim of this study was to compare the acute effects produced by a single bout of three different exercise modalities on short-term blood pressure variability.

METHODS

The study enrolled 21 sedentary male patients with hypertension and a mean age of 63 ± 7.2 years. Blood pressure variability was evaluated through ambulatory blood pressure monitoring that was performed twice: during an ordinary daily activity and after an exercise session lasting 60 minutes. Patients were divided into three groups according to the different exercise modality performed during the session: aerobic continuous training, interval training or combined training including aerobic and resistance training.

RESULTS

Twenty-four-hour systolic blood pressure variability increased in the interval training group, was unchanged in the aerobic continuous training group and decreased in the combined training group (intergroup P = 0.03). Daytime systolic blood pressure variability increased in the interval training and aerobic continuous training groups while it decreased in the combined training group (intergroup P = 0.0006). Twenty-four-hour diastolic blood pressure variability decreased in the aerobic continuous training and combined training groups while it increased in the interval training group (intergroup P = 0.002).

CONCLUSION

Different training modalities have similar hypotensive action but exert different acute effects on blood pressure variability. Combined training seems to be the most suitable training modality for sedentary men with hypertension.

Resting heart rate in late adolescence and long term risk of cardiovascular disease in Swedish men

AIM

To investigate the association of resting heart rate (RHR) measured in late adolescence with the long term risk of myocardial infarction (MI), ischemic stroke (IS), heart failure (HF), atrial fibrillation (AF), cardiovascular- and all-cause death.

METHODS AND RESULTS

We followed a cohort of Swedish men enrolled for conscription in 1968-2005 (n = 1,008,485; mean age = 18.3 years) until December 2014. Outcomes were collected from the national inpatient - (IPR), outpatient - (OPR) and cause of death registries. Cox proportional hazard models were used to analyze the longitudinal association between RHR and outcomes while adjusting for potential confounders. While we found no independent association between RHR and risk of IS or MI when comparing the highest with the lowest quintile of the RHR distribution, but a positive association persisted between RHR and incident HF (Hazard ratio (HR) = 1.39 [95% confidence interval (CI) = 1.29-1.49]) after adjustment for body mass index (BMI) and blood pressure (BP). In similarly adjusted models, an inverse association was found for AF while there were weaker associations with death from cardiovascular disease (CVD) and all causes (adjusted HR = 1.12 [CI = 1.04-1.21] and 1.20 [CI = 1.17-1.24]). After further adjustment for cardiorespiratory fitness (CRF), the associations persisted for HF (HR = 1.26 [1.17-1.35] for any diagnostic position and HR = 1.43 [1.28-1.60] for HF as a main diagnosis) and for all-cause death (HR 1.09 [1.05-1.12]) but not for CVD death.

CONCLUSION

Adolescent RHR is associated with future risk of HF and death, independently of BP, BMI and CRF, but not with CVD death, MI or IS, suggesting a causal pathway between elevated heart rate and myocardial dysfunction.

Does resistance training modulate cardiac autonomic control? A systematic review and meta-analysis

PURPOSE

To systematically evaluate the literature on the effects of resistance training (RT) on cardiac autonomic control in healthy and diseased individuals.

METHODS

Electronic databases Pubmed, PEDro, and Scopus were systematically searched from their inception up to June 2018. Randomized controlled trials, quasi-experimental trials, and cross-over controlled trials investigating the effect of RT (of at least 4 weeks duration) on cardiac autonomic control assessed either by linear or non-linear measures of heart rate variability (HRV), baroreflex sensitivity, or post-exercise heart rate recovery were included. Of the studies retrieved, 28 were included in the systematic review. Meta-analysis was performed on 21 studies of the total 28 studies.

RESULTS

Quality and characteristic assessment revealed fair quality evidence. The majority of literature on healthy humans suggested no change in cardiac autonomic control following RT. Standardized mean differences (SMD) showed a significant effect of RT on root mean square of successive differences between adjacent inter-beat (R-R) intervals (RMSSD) [SMD 0.96, 95% confidence interval (CI) 0.20-1.73; p = 0.01], ratio of low- to high-frequency power of HRV (LF/HF ratio; SMD -0.72, 95% CI -1.03 to -0.42; p < 0.00001), standard deviation of the instantaneous beat-to-beat variability (SD1; SMD 1.78, 95% CI 1.07-2.49, p < 0.00001), and sample entropy (SMD 1.17, 95% CI 0.36-1.97, p = 0.005) in diseased individuals.

CONCLUSION

This rigorous systematic analysis revealed that RT has no or minimal effects on cardiac autonomic control of healthy individuals, but RT leads to improvement in cardiac autonomic control of diseased individuals.

Cardiovascular response to bouts of exercise with blood flow restriction

[Purpose] Occlusion training with low-intensity resistance exercises and blood flow restriction increases muscle cross-sectional area and strength. This form of training is used in rehabilitation; therefore, the aim of this study was to examine the effect of one occlusion training session on the cardiovascular response to bouts of exercise. [Subjects and Methods] Two groups took part: a control group without blood flow restriction and an experimental group with blood flow restriction. A single training session was used with the exercise intensity set at 40% of the one repetition maximum. Maximum voluntary contraction, arterial blood pressure, and electrocardiogram measurements were performed. [Results] Heart rate was slightly higher in the control group. The performed training had no effect on diastolic blood pressure in either group, however, a tendency for a small systolic blood pressure increase was observed during the session in the experimental group. JT interval changes did not reveal significant differences between groups. There were no significant changes in ST-segment depression during the exercise or at rest. A lower tendency for JT/RR increases was observed during the repeated exercise tasks with partial blood flow restriction. [Conclusion] Low intensity exercises carried out with a partial blood flow restriction do not result in significant overload of cardiac function.

Visit-to-Visit Variability and Reduction in Blood Pressure After a 3-Month Cardiac Rehabilitation Program in Patients With Cardiovascular Disease

Visit-to-visit variability (VVV) in blood pressure (BP) has been shown to be a predictor of cardiovascular events. It is unknown whether CR can improve VVV in BP as well as reducing BP. We enrolled 84 patients who had cardiovascular disease (CVD) and participated in a 3-month CR program. We measured systolic and diastolic BP (SBP and DBP), pulse pressure (PP), and heart rate (HR) before exercise training at each visit and determined VVV in BP or HR expressed as the standard deviation of the average BP or HR. Patients who had uncontrolled BP at baseline and who did not change their antihypertensive drugs throughout the study period showed a significant reduction of both SBP and DBP with a decrease in PP after 3 months. Patients who did not change their antihypertensive drugs were divided into larger (L-) and smaller (S-) VVV in the SBP groups and L- and S-VVV in the DBP groups according to the average value of VVV in SBP or DBP. In the L-VVV in the SBP and DBP groups, VVV in SBP and DBP in the 1st month was significantly decreased after the 3rd month in both groups. HR at baseline was significantly decreased after 3 months. In addition, CR induced a significant increase in the level of high-density lipoprotein cholesterol (HDL-C) in blood. In conclusion, CR improved VVV in BP in patients with L-VVV in BP and evoked a significant reduction in HR and an increase in HDL-C. These effects due to the CR program may be cardioprotective.

Assessment of various parameters using simple non-invasive tests in patients with cardiovascular diseases with or without cardiac rehabilitation

Cardiac rehabilitation (CR) improves cardiac function and exercise capacity in patients with cardiovascular disease (CVD). Simpler techniques are needed for use by physicians in the examination room to assess the usefulness of CR. We enrolled 46 consecutive CVD patients in a CR program (CR group) and prospectively followed them for 3 months. We compared them to 18 age-, gender- and body mass index-matched CVD patients without CR (non-CR group). Various parameters were measured at baseline and after 3 months using 3 simple non-invasive tests: severity of atherosclerosis [arterial velocity pulse index and arterial pressure volume index (API)] were determined using PASESA®, an autonomic nerve total activity amount index and a coefficient of variation of the R–R interval (CVRR) were determined using eHEART®, and peripheral resistance index, pressure rate product, stroke volume and cardiac index were determined using nico®]. There were no significant differences in patient characteristics including percentages (%) of ischemic heart disease and heart failure between the non-CR and CR groups. Systolic blood pressure (SBP), diastolic BP, heart rate and API at baseline significantly decreased and CVRR at baseline significantly increased after 3 months in the CR group, but not in the non-CR group. In addition, ΔAPI (Δ = the value after 3 months minus the value at baseline) was positively associated with ΔSBP in the CR group. In conclusion, CR significantly decreased BP and improved atherosclerosis and sympathetic nerve activity. These findings suggest that simple non-invasive tests may be useful for assessing the effects of CR.

Neuroendocrine and cardiovascular reactions to acute psychological stress are attenuated in smokers

A number of studies have now examined the association between smoking and the magnitude of physiological reactions to acute psychological stress. However, no large-scale study has demonstrated this association incorporating neuroendocrine in addition to cardiovascular reactions to stress. The present study compared neuroendocrine and cardiovascular reactions to acute stress exposure in current smokers, ex-smokers, and those who had never smoked in a large community sample. Salivary cortisol, systolic and diastolic blood pressure, heart rate and frequency components of systolic blood pressure and heart rate variability were measured at rest and during exposure to a battery of three standardized stress tasks in 480 male and female participants from the Dutch Famine Birth Cohort Study. Current smokers had significantly lower cortisol, systolic and diastolic blood pressure, and heart rate reactions to stress. They also exhibited smaller changes in the low frequency band of blood pressure variability compared to ex- and never smokers. There were no group differences in stress related changes in overall heart rate variability as measured by the root mean square of successive interbeat interval differences or in the high frequency band of heart rate variability. In all cases, effects remained significant following statistical adjustment for a host of variables likely to be associated with reactivity and/or smoking. In secondary analyses, there were no significant associations between lifetime cigarette consumption or current consumption and stress reactivity. In conclusion, compared to non-smokers and ex-smokers, current smokers exhibited attenuated neuroendocrine and cardiovascular reactions to acute psychological stress. Among smokers and ex-smokers, there is no evidence that lifetime exposure was associated with physiological reactions to acute stress, nor that current levels of cigarette consumption were associated with reactivity. It is possible, then, that attenuated stress reactivity may be a marker for an increased susceptibility to take up and/or maintain smoking behaviour once initiated.

The impact of aerobic exercise on blood pressure variability

There is increasing evidence that blood pressure variability (BPV, variation of blood pressure over time) constitutes a strong and independent marker of cardiovascular risk. The all-cause mortality is >50% greater in subjects with a standard deviation of inter-visit blood pressure >5 mm Hg. Regular aerobic exercise reduces blood pressure and is recommended by current hypertension guidelines as a basic lifestyle modification. It remains elusive, however, whether aerobic exercise is able to reduce BPV as well. In total, 72 hypertensive subjects were randomly assigned to an 8-12-week treadmill exercise program (target lactate 2.0±0.5 mmol l(-1)) or sedentary control. Blood pressure was measured by 24 h-ambulatory blood pressure monitoring (ABP). Two aspects of BPV were assessed: the variability of ABP and the variability of blood pressure on exertion. The coefficient of variation (CV) was used as a statistical measure of BPV. The CV of systolic daytime ABP was defined as primary outcome. The exercise program significantly decreased systolic and diastolic daytime ABP by 6.2±10.2 mm Hg (P<0.01) and 3.0±6.3 mm Hg (P=0.04), respectively. Moreover, it reduced blood pressure on exertion and increased physical performance (P<0.05 each). Exercise had no impact, however, on the CV of daytime (10.2±2.7 vs. 9.8±2.6%, P=0.30) and night-time systolic (8.9±3.2 vs. 10.5±4.1%, P=0.10) and diastolic ABP (daytime 11.5±3.3 vs. 11.5±3.1%, night-time 12.0±4.3 vs. 13.8±5.2%; P>0.05 each). Regular aerobic exercise is a helpful adjunct to control blood pressure in hypertension, but it has no effect on 24 h- BPV, an independent predictor of cardiovascular risk.

Cardiovascular reactivity, stress, and physical activity

Psychological stress has been proposed as a major contributor to the progression of cardiovascular disease (CVD). Acute mental stress can activate the sympathetic-adrenal-medullary (SAM) axis, eliciting the release of catecholamines (NE and EPI) resulting in the elevation of heart rate (HR) and blood pressure (BP). Combined stress (psychological and physical) can exacerbate these cardiovascular responses, which may partially contribute to the elevated risk of CVD and increased proportionate mortality risks experienced by some occupations (e.g., firefighting and law enforcement). Studies have supported the benefits of physical activity on physiological and psychological health, including the cardiovascular response to acute stress. Aerobically trained individuals exhibit lower sympathetic nervous system (e.g., HR) reactivity and enhanced cardiovascular efficiency (e.g., lower vascular reactivity and decreased recovery time) in response to physical and/or psychological stress. In addition, resistance training has been demonstrated to attenuate cardiovascular responses and improve mental health. This review will examine stress-induced cardiovascular reactivity and plausible explanations for how exercise training and physical fitness (aerobic and resistance exercise) can attenuate cardiovascular responses to stress. This enhanced functionality may facilitate a reduction in the incidence of stroke and myocardial infarction. Finally, this review will also address the interaction of obesity and physical activity on cardiovascular reactivity and CVD.

No effect of exercise on urinary 6-sulfatoxymelatonin and catecholamines in young women participating in a 16-week randomized controlled trial

BACKGROUND

Women with breast cancer have decreased levels of melatonin or its metabolite in plasma and/or urine.

METHODS

We measured serum melatonin, urinary 6-sulfatoxymelatonin, catecholamines, and cortisol in 141 sedentary young female participants in a clinical trial comparing 150 min/wk aerobic exercise for 4 months to no-exercise controls. Demographics, health surveys, body composition, sleep quality, fitness levels, and blood and urine samples were obtained at baseline and 16 weeks.

RESULTS

There were no differences between groups at baseline in demographics, exercise, sleep habits, or study hormones. There were also no significant differences between groups in any of the hormones at 16 weeks.

CONCLUSION

Sixteen weeks of exercise had minimal effects on melatonin secretion of young women.

IMPACT

There is convincing evidence that exercise protects against breast cancer, but this does not appear to occur through changes in melatonin secretion.