The Impact of Exercise Training on Conduit Artery Wall Thickness and Remodeling in Chronic Heart Failure Patients

Resistance is not futile: a systematic review of the benefits, mechanisms and safety of resistance training in people with heart failure

Exercise offers many physical and health benefits to people with heart failure (CHF), but aerobic training (AT) predominates published literature. Resistance training (RT) provides additional and complementary health benefits to AT in people with CHF; we aimed to elucidate specific health benefits accrued, the mechanism of effect and safety of RT. We conducted a systematic search for RT randomised, controlled trials in people with CHF, up until August 30, 2023. RT offers several benefits including improved physical function (peak VO2 and 6MWD), quality of life, cardiac systolic and diastolic function, endothelial blood vessel function, muscle strength, anti-inflammatory muscle markers, appetite and serious event rates. RT is beneficial and improves peak VO2 and 6MWD, partly restores normal muscle fibre profile and decreases inflammation. In turn this leads to a reduced risk or impact of sarcopenia/cachexia via effect on appetite. The positive impact on quality of life and performance of activities of daily living is related to improved function, which in turn improves prognosis. RT appears to be safe with only one serious event reported and no deaths. Nevertheless, few events reported to date limit robust analysis. RT appears to be safe and offers health benefits to people with CHF. RT modifies the adverse muscle phenotype profile present in people with CHF and it appears safe. Starting slowly with RT and increasing load to 80% of 1 repetition maximum (RM) appears to offer optimal benefit.

Effects of exercise-based cardiac rehabilitation delivery modes on exercise capacity and health-related quality of life in heart failure: a systematic review and network meta-analysis

Background

This review aimed to compare the relative effectiveness of different exercise-based cardiac rehabilitation (ExCR) delivery modes (centre-based, home-based, hybrid and technology-enabled ExCR) on key heart failure (HF) outcomes: exercise capacity, health-related quality of life (HRQoL), HF-related hospitalisation and HF-related mortality.

Methods and results

Randomised controlled trials (RCTs) published through 20 June 2021 were identified from six databases, and reference lists of included studies. Risk of bias and certainty of evidence were evaluated using the Cochrane tool and Grading of Recommendations Assessment, Development and Evaluation, respectively. Bayesian network meta-analysis was performed using R. Continuous and binary outcomes are reported as mean differences (MD) and ORs, respectively, with 95% credible intervals (95% CrI). One-hundred and thirty-nine RCTs (n=18 670) were included in the analysis. Network meta-analysis demonstrated improvements in VO₂peak following centre-based (MD (95% CrI)=3.10 (2.56 to 3.65) mL/kg/min), home-based (MD=2.69 (1.67 to 3.70) mL/kg/min) and technology-enabled ExCR (MD=1.76 (0.27 to 3.26) mL/kg/min). Similarly, 6 min walk distance was improved following hybrid (MD=84.78 (31.64 to 138.32) m), centre-based (MD=50.35 (30.15 to 70.56) m) and home-based ExCR (MD=36.77 (12.47 to 61.29) m). Incremental shuttle walk distance did not improve following any ExCR delivery modes. Minnesota living with HF questionnaire improved after centre-based (MD=−10.38 (−14.15 to –6.46)) and home-based ExCR (MD=−8.80 (−13.62 to –4.07)). Kansas City Cardiomyopathy Questionnaire was improved following home-based ExCR (MD=20.61 (4.61 to 36.47)), and Short Form Survey 36 mental component after centre-based ExCR (MD=3.64 (0.30 to 6.14)). HF-related hospitalisation and mortality risks reduced only after centre-based ExCR (OR=0.41 (0.17 to 0.76) and OR=0.42 (0.16 to 0.90), respectively). Mean age of study participants was only associated with changes in VO₂peak.

Conclusion

ExCR programmes have broader benefits for people with HF and since different delivery modes were comparably effective for improving exercise capacity and HRQoL, the selection of delivery modes should be tailored to individuals’ preferences.

Resistance training in heart failure patients: a systematic review and meta-analysis

Aerobic training (AT) has been the primary mode of exercise training in cardiac rehabilitation. Historically, the reason for the prescription of AT was that it was speculated that although RT may be beneficial for some clinical outcomes, it may have an adverse effect on ventricular structure and function. However, RT has now made its way into current cardiac rehabilitation guidelines, including those directed towards patients with HF, albeit differences exist across institutions and guidelines. A systematic search of PubMed, EMBASE and Cochrane Trials Register on April 30, 2021, was conducted for exercise-based rehabilitation trials in HF. Randomised and controlled trials that reported on resistance training versus usual care or trials that directly compared RT to an AT intervention were included. Resistance training versus controls improves parameters of lower (SMD 0.76 (95%CI 0.26, 1.25, p = 0.003] and upper extremity muscle strength (SMD 0.85 (95%CI 0.35, 1.35), p = 0.0009], both key parameters of physical function throughout the lifespan. Importantly, RT in isolation, versus control, improves VO2peak [MD: 2.64 ml/kg/min (95%CI 1.67, 3.60), p < 0.00001] and 6MWD [MD: 49.94 m (95%CI 34.59, 65.29), p < 0.00001], without any detrimental effect on left ventricular parameters. Resistance training in HF patients is safe and improves parameters of physical function and quality of life. Where people with HF are unable to, or are not inclined to, partake in aerobic activity, RT alone is appropriate to elicit meaningful benefit.

Sex Differences in Exercise-Training-Related Functional and Morphological Adaptation of Rat Gracilis Muscle Arterioles

Background

The cardiovascular effects of training have been widely investigated; however, few studies have addressed sex differences in arteriolar adaptation. In the current study, we examined the adaptation of the gracilis arterioles of male and female rats in response to intensive training.

Methods

Wistar rats were divided into four groups: male exercise (ME) and female exercise (FE) animals that underwent a 12-week intensive swim-training program (5 days/week, 200 min/day); and male control (MC) and female control (FC) animals that were placed in water for 5 min daily. Exercise-induced cardiac hypertrophy was confirmed by echocardiography. Following the training, the gracilis muscle arterioles were prepared, and their biomechanical properties and functional reactivity were tested, using pressure arteriography. Collagen and smooth muscle remodeling were observed in the histological sections.

Results

Left ventricular mass was elevated in both sexes in response to chronic training. In the gracilis arterioles, the inner radius and wall tension increased in female animals, and the wall thickness and elastic modulus were reduced in males. Myogenic tone was reduced in the ME group, whereas norepinephrine-induced vasoconstriction was elevated in the FE group. More pronounced collagen staining was observed in the ME group than in the MC group. Relative hypertrophy and tangential stress of the gracilis arterioles were higher in females than in males. The direct vasoconstriction induced by testosterone was lower in females and was reduced as an effect of exercise in males.

Conclusion

The gracilis muscle arteriole was remodeled as a result of swim training, and this adaptation was sex dependent.

A systematic review of rehabilitation in chronic heart failure: evaluating the reporting of exercise interventions

A large body of research supports the use of exercise to improve symptoms, quality of life, and physical function in patients with chronic heart failure. Previous reviews have focused on reporting outcomes of exercise interventions such as cardiorespiratory fitness. However, none have critically examined exercise prescription. The aim of this review was to evaluate the reporting and application of exercise principles in randomised control trials of exercise training in patients with chronic heart failure. A systematic review of exercise intervention RCTs in patients with CHF, using the Consensus on Exercise Reporting Template (CERT), was undertaken. The Ovid Medline/PubMed, Embase, Scopus/Web of Science, and Cochrane Library and Health Technology Assessment Databases were searched from 2000 to June 2020. Prospective RCTs in which patients with CHF were randomized to a structured exercise programme were included. No limits were placed on the type or duration of exercise structured exercise programme or type of CHF (i.e. preserved or reduced ejection fraction). We included 143 studies, comprising of 181 different exercise interventions. The mean CERT score was 10 out of 19, with no study achieving a score of 19. Primarily, details were missing regarding motivational strategies, home-based exercise components, and adherence/fidelity to the intervention. Exercise intensity was the most common principle of exercise prescription missing from intervention reporting. There was no improvement in the reporting of exercise interventions with time (R²  = 0.003). Most RCTs of exercise training in CHF are reported with insufficient detail to allow for replication, limiting the translation of evidence to clinical practice. We encourage authors to provide adequate details when reporting future interventions. Where journal word counts are restrictive, we recommend using supplementary material or publishing trial protocols prior to beginning the study.

Prioritizing movement to address the frailty phenotype in heart failure

Frailty is a highly prevalent multisystem syndrome in older adults with heart failure (HF) and is associated with poor clinical prognosis and increased complexity of care. While frailty is neither disease nor age specific, it is a clinical manifestation of aging-related processes that reflects a reduced physiological ability to tolerate and recover from stress associated with aging, disease, or therapy. Within this context, physical frailty, which is distinctly oriented to physical functional domains (e.g., muscle weakness, slowness, and low activity), has been recognized as a critical vital sign in older persons with HF. Identification and routine assessment of physical frailty, using objective physical performance measures, may guide the course of patient-centered treatment plans that maximize the likelihood of improving clinical outcomes in older HF patients. Exercise-based rehabilitation is a primary therapy to improve cardiovascular health in patients with HF; however, the limited evidence supporting the effectiveness of exercise tailored to older and frail HF patients underscores the current gaps in management of their care. Interdisciplinary exercise interventions designed with consideration of physical frailty as a therapeutic target may be an important strategy to counteract functional deficits characteristic of frailty and HF, and to improve patient-centered outcomes in this population. The purpose of this current review is to provide a better understanding of physical frailty and its relation to management of care in older patients with HF. Implications of movement-based interventions, including exercise and physical rehabilitation, to prevent or reverse physical frailty and improve clinical outcomes will further be discussed.

Resistance training to reduce resting blood pressure and increase muscle strength in users and non-users of anti-hypertensive medication: A meta-analysis

Objective: The aim of this study was to conduct a systematic review with meta-analysis to analyze the effect of resistance training variables prescription on resting systolic (SBP) and diastolic blood pressure (DBP) and muscle strength changes. Methods: The search was conducted in the PubMed, Web of Science, and SPORTDiscus databases until August 2020 for randomized controlled trials with non-exercising control group. Results: In total, 36 studies qualified for inclusion in this meta-analysis. Eleven studies included users of antihypertensive medication, while the remaining 25 studies were conducted with non-users of antihypertensive medication. Resistance training only reduced SBP (-0.56 [-0.77 to -0.35]; P < .001) and DBP (-0.46 [-0.68 to -0.24]; P < .001) in anti-hypertensive medication users, with changes ranging from -6.1 to -2.8 mmHg for SBP and -4.6 to -1.6 mmHg for DBP. Muscle strength increased significantly in both users (0.76 [0.49 to 1.02]; P < .001) and non-users of antihypertensive medication (0.94 [0.71 to 1.16]; P < .001). Resistance training should be performed by users and non-users of antihypertensive medication for 8 to 16 weeks (2 to 3 days a week) and 8 to 12 non-failure repetitions. However, users should train with less load (60-80 vs 70-85% 1RM) and exercise sets (1-3 vs 2-4) than non-users of antihypertensive medication. Conclusion: Resistance training increases muscle strength and reduces resting SBP and DBP in individuals under BP pharmacological therapy, while in individuals who do not use antihypertensive drugs, resistance training only increases strength.

Effects of Land versus Water Walking Interventions on Vascular Function in Older Adults

PURPOSE

Endothelial dysfunction is an early and integral atherogenic event. Interventions that improve endothelial function also reduce cardiovascular risk. Due largely to the direct hemodynamic effects of repetitive exercise on the artery wall, exercise training has shown to enhance endothelial function. Land walking (LW) and water walking (WW) induce distinct hemodynamic responses, so the comparison of their effects provides an approach to study shear stress effects on endothelial function. We hypothesized that LW and WW training would have different effects on peripheral artery endothelial function.

METHODS

Fifty-one sedentary, older (age = 61.9 ± 6.6 yr, 23.5% male) individuals were randomized into one of three groups: control (n = 16), or one of two exercise groups consisting of 3 × 50 min supervised and individually tailored walking sessions per week for 24 consecutive weeks, performed either on LW (n = 17) or on WW (n = 18). Brachial artery endothelial function (flow-mediated dilation) and smooth muscle cell function (glyceryl trinitrate administration) were tested in all participants before (week 0) and after (week 24) the intervention.

RESULTS

Differences were apparent in flow-mediated dilation change between the LW group (week 0, 5.39% ± 0.71%, to week 24, 7.77% ± 0.78%; P = 0.009) and the control group (week 0, 5.87% ± 0.73%, to week 24, 5.78% ± 0.78%). No differences in artery dilation response were found after glyceryl trinitrate administration (all P > 0.05).

CONCLUSION

This study suggests that 6-month center-based LW may be superior to WW in terms of improvement in arterial endothelial function in older sedentary individuals.

Cardiopulmonary exercise capacity and quality of life of patients with heart failure undergoing a functional training program: study protocol for a randomized clinical trial

BACKGROUND

Exercise intolerance is a common finding in heart failure that generates a vicious cycle in which the individual starts to limit his activities even more due to progressive fatigue. Regular physical exercise can increase the cardiopulmonary exercise capacity of these individuals. A new approach to physical exercise, known as functional training, could improve the oxygen consumption and quality of life of patients with heart failure; however, there is no information about the effect of this modality of exercise in this patient population. This randomized trial will compare the effects of 36 sessions of functional training versus strength training in heart failure patients.

METHODS

This randomized parallel-design examiner-blinded clinical trial includes individuals of both sexes aged ≥40 years receiving regular follow-up at a single academic hospital. Subjects will be randomly allocated to an intervention group (for 12-week functional training) or an active comparator group (for 12-week strength training). The primary outcomes will be the difference from baseline to the 3-month time point in peak oxygen consumption on cardiopulmonary exercise testing and quality of life assessed by the Minnesota Living with Heart Failure Questionnaire. Secondary outcome measures will include functionality assessed by the Duke Activity Status Index and gait speed test; peripheral and inspiratory muscular strength, assessed by hand grip and manovacuometry testing, respectively; endothelial function by brachial artery flow-mediated dilation; lean body mass by arm muscle circumference; and participant adherence to the exercise programs classified as a percentage of the prescribed exercise dose.

DISCUSSION

The functional training program aims to improve the functional capacity of the individual using exercises that relate to his specific physical activity transferring gains effectively to one's daily life. In this context, we believe that that functional training can increase the cardiopulmonary exercise capacity and quality of life of patients with heart failure. The trial has been recruiting patients since October 2017.

TRIAL REGISTRATION

NCT03321682. Registered on October 26, 2017.

Exercise as a prescription for patients with various diseases

A growing understanding of the benefits of exercise over the past few decades has prompted researchers to take an interest in the possibilities of exercise therapy. Because each sport has its own set of characteristics and physiological complications that tend to occur during exercise training, the effects and underlying mechanisms of exercise remain unclear. Thus, the first step in probing the effects of exercise on different diseases is the selection of an optimal exercise protocol. This review summarizes the latest exercise prescription treatments for 26 different diseases: musculoskeletal system diseases (low back pain, tendon injury, osteoporosis, osteoarthritis, and hip fracture), metabolic system diseases (obesity, type 2 diabetes, type 1 diabetes, and nonalcoholic fatty liver disease), cardio-cerebral vascular system diseases (coronary artery disease, stroke, and chronic heart failure), nervous system diseases (Parkinson's disease, Huntington's disease, Alzheimer's disease, depression, and anxiety disorders), respiratory system diseases (chronic obstructive pulmonary disease, interstitial lung disease, and after lung transplantation), urinary system diseases (chronic kidney disease and after kidney transplantation), and cancers (breast cancer, colon cancer, prostate cancer, and lung cancer). Each exercise prescription is displayed in a corresponding table. The recommended type, intensity, and frequency of exercise prescriptions are summarized, and the effects of exercise therapy on the prevention and rehabilitation of different diseases are discussed.

Long-Term Aerobic Exercise Improves Vascular Function Into Old Age: A Systematic Review, Meta-Analysis and Meta Regression of Observational and Interventional Studies

There is an emerging body of literature relating to the effectiveness of frequent aerobic exercise as a prophylactic for age-associated dysfunction of large arteries, yet systematic evaluation and precise estimate of this effect is unknown. We conducted a systematic review and meta-analysis of controlled studies examining flow mediated dilatation (FMD) of athletic older persons and otherwise healthy sedentary counterparts to (i) compare FMD as a determinant of endothelial function between athletes and sedentary individuals and, (ii) summarize the effect of exercise training on FMD in studies of sedentary aging persons. Studies were identified from systematic search of major electronic databases from inception to January 2018. Study quality was assessed before conducting a random effects meta-analysis to calculate a pooled ES (mean difference) with 95% CI's. Thirteen studies [4 interventional (n = 125); 10 cross-sectional [including one study from the interventional analysis; (n = 485)] with age ranges from 62 to 75 years underwent quantitative pooling of data. The majority of study participants were male. Older athletes had more favorable FMD compared with sedentary controls (2.1%; CI: 1.4, 2.8%; P < 0.001). There was no significant improvement in the vascular function of sedentary cohorts following a period of exercise training (0.7%; CI: −0.675, 2.09%; P = 0.316). However, there was a significant increase in baseline diameter from pre to post intervention (0.1 mm; CI: 0.07, 0.13 mm; P < 0.001). In addition, there was no significant difference in endothelial independent vasodilation between the trained and sedentary older adults (1.57%; CI: −0.13, 3.27%; P = 0.07), or from pre to post exercise intervention (1.48%; CI: −1.34, 4.3%; P = 0.3). In conclusion, long-term aerobic exercise appears to attenuate the decline in endothelial vascular function, a benefit which is maintained during chronological aging. However, currently there is not enough evidence to suggest that exercise interventions improve vascular function in previously sedentary healthy older adults.

Resistance exercise enhances oxygen uptake without worsening cardiac function in patients with systolic heart failure: a systematic review and meta-analysis

Recent literature suggests that resistance training (RT) improves peak oxygen uptake ([Formula: see text] peak), similarly to aerobic exercise (AE) in patients with heart failure (HF), but its effect on cardiac remodeling is controversial. Thus, we examined the effects of RT and AE on [Formula: see text] peak and cardiac remodeling in patients with heart failure (HF) via a systematic review and meta-analysis. MEDLINE, EMBASE, Cochrane Library and CINAHL, AMEDEO and PEDro databases search were extracted study characteristics, exercise type, and ventricular outcomes. The main outcomes were [Formula: see text] peak (ml kg^-1 min^-1), LVEF (%) and LVEDV (mL). Fifty-nine RCTs were included. RT produced a greater increase in [Formula: see text] peak (3.57 ml kg^-1 min^-1, P < 0.00001, I ² = 0%) compared to AE (2.63 ml kg^-1 min^-1, P < 0.00001, I ² = 58%) while combined RT and AE produced a 2.48 ml kg^-1 min^-1 increase in [Formula: see text]; I ² = 69%) compared to control group. Comparison among the three forms of exercise revealed similar effects on [Formula: see text] peak (P = 0.84 and 1.00, respectively; I ² = 0%). AE was associated with a greater gain in LVEF (3.15%; P < 0.00001, I ² = 17%) compared to RT alone or combined exercise which produced similar gains compared to control groups. Subgroup analysis revealed that AE reduced LVEDV (- 10.21 ml; P = 0.007, I ² = 0%), while RT and combined RT and AE had no effect on LVEDV compared with control participants. RT results in a greater gain in [Formula: see text] peak, and induces no deleterious effects on cardiac function in HF patients.

Exercise for Preventing Hospitalization and Readmission in Adults With Congestive Heart Failure

We critically appraised all available evidence regarding exercise interventions for improving patient survival and reducing hospital admissions in adults with chronic heart failure (HF). We searched 4 databases up to April 2018 and graded the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation working group approach. We reviewed 7 meta-analyses and the publications of 48 randomized controlled trials (RCTs). In HF with reduced ejection fraction, low-quality evidence suggests that exercise prevents all-cause hospitalizations [Relative risk (RR), 0.77; 95% confidence interval (CI), 0.63 to 0.93; 1328 patients in 15 RCTs] and hospitalizations due to HF (RR, 0.57; 95% CI, 0.37 to 0.88; 1073 patients in 13 RCTs) and improves quality of life (standardized mean difference, -0.37; 95% CI, -0.60 to -0.14; 1270 patients in 25 RCTs) but has no effect on mortality. In HF with preserved ejection fraction, low-quality evidence suggests that exercise improves peak oxygen uptake (mean difference, 2.36; 95% CI, 1.16 to 3.57; 171 patients in 3 RCTs) and quality of life (mean difference, -4.65; 95% CI, -8.46 to -0.83; 203 patients in 4 RCTs). In patients after heart transplantation, low-quality evidence suggests that exercise improves peak oxygen uptake (standardized mean difference, 0.68; 95% CI, 0.43 to 0.93; 284 patients in 9 RCTs) but does not improve quality of life. In order to reduce hospitalization and improve quality of life for adults with HF and reduced ejection fraction, clinicians should recommend exercise interventions. For adults with HF and preserved ejection fraction and in those undergoing heart transplantation, clinicians may recommend exercise interventions in order to improve peak oxygen uptake.

Effects of Exercise on Vascular Function, Structure, and Health in Humans

Physical activity has profound impacts on the vasculature in humans. Acute exercise induces immediate changes in artery function, whereas repeated episodic bouts of exercise induce chronic functional adaptation and, ultimately, structural arterial remodeling. The nature of these changes in function and structure are dependent on the characteristics of the training load and may be modulated by other factors such as exercise-induced inflammation and oxidative stress. The clinical implications of these physiological adaptations are profound. Exercise impacts on the development of atherosclerosis and on the incidence of primary and secondary cardiovascular events, including myocardial infarction and stroke. Exercise also plays a role in the amelioration of other chronic diseases that possess a vascular etiology, including diabetes and dementia. The mechanisms responsible for these effects of exercise on the vasculature are both primary and secondary in nature, in that the benefits conferred by changes in cardiovascular risk factors such as lipid profiles and blood pressure occur in concert with direct effects of arterial shear stress and mechanotransduction. From an evolutionary perspective, exercise is an essential stimulus for the maintenance of vascular health: exercise is vascular medicine.

Effect of intradialytic resistance training on pulse wave velocity and associated cardiovascular disease biomarkers in end stage renal disease

AIMS

Cardiovascular disease (CVD) is the leading cause of mortality in patients with end-stage renal disease (ESRD) receiving maintenance haemodialysis treatment. This study investigated the effect of a 12-week intradialytic progressive resistance training (PRT) intervention on pulse wave velocity (PWV) and associated haemodynamic, anthropometric, and hematologic outcomes in patients with ESRD.

METHODS

Twenty-two patients with ESRD (59% men, 71.3 ± 11.0 years) were recruited. Supervised PRT (three sets of 11 exercises) was prescribed three times per week during routine dialysis. The primary outcome was brachial-ankle PWV via applanation tonometry. Secondary outcomes included augmentation index, brachial and aortic blood pressures, endothelial progenitor cells, C-reactive protein, blood lipids and anthropometrics.

RESULTS

The intradialytic PRT regimen resulted in no significant change in PWV between control and intervention periods [mean difference = 0 (95% CI = -0.1 to 0.1); P = 0.58]. Similarly, no significant change was noted in any secondary outcome measures between the control and intervention periods. Post-hoc analyses limited to high adherers (≥75% attendance; n = 11) did not differ from the primary analysis, indicating no dose-response effect of our intervention.

CONCLUSION

Our 12-week PRT intervention did not change PWV or any secondary outcomes. Future studies should determine if higher dosages of intradialytic PRT (i.e. longer duration and/or higher intensity) can be applied as a method to improve arterial stiffness to potentially reduce cardiovascular disease and associated mortality this cohort.

Exercise attenuates dexamethasone-induced hypertension through an improvement of baroreflex activity independently of the renin-angiotensin system

Dexamethasone-induced hypertension may be caused by baroreflex alterations or renin-angiotensin system (RAS) exacerbation. Aerobic training has been recommended for hypertension treatment, but the mechanisms responsible for reduction of arterial pressure (AP) in dexamethasone (DEX) treated rats are still inconclusive.This study evaluated whether mechanisms responsible for training-induced attenuation of hypertension involve changes in autonomic nervous system and in RAS components. Rats underwent aerobic training protocol on treadmill or were kept sedentary for 8 weeks. Additionally, animals were treated with DEX during the last 10 days of exercise. Body weight (BW), AP and baroreflex activity were analyzed. Tibialis anterior (TA), soleus (SOL) and left ventricle (LV) were collected for evaluation of RAS components gene expression and protein levels. Dexamethasone decreased BW (20%), caused TA atrophy (16%) and increased systolic AP (SAP, 16%) as well as decreased baroreflex activity. Training attenuated SAP increase and improved baroreflex activity, although it did not prevent DEX-induced BW reduction and muscle atrophy. Neither DEX nor training caused expressive changes in RAS components. In conclusion, exercise training was effective in attenuating hypertension induced by DEX and this response may be mediated by a better autonomic balance through an improvement of baroreflex activity rather than changes in RAS components.

Impact of Age and Aerobic Exercise Training on Conduit Artery Wall Thickness: Role of the Shear Pattern

Hemodynamic shear stress is the frictional force of blood on the arterial wall. The shear pattern in the conduit artery affects the endothelium and may participate in the development and progression of atherosclerosis. We investigated the role of the shear pattern in age- and aerobic exercise-induced changes in conduit artery wall thickness via cross-sectional and interventional studies. In a cross-sectional study, we found that brachial shear rate patterns and brachial artery intima-media thickness (IMT) correlated with age. Additionally, brachial artery shear rate patterns were associated with brachial artery IMT in 102 middle-aged and older individuals. In an interventional study, 39 middle-aged and older subjects were divided into 2 groups: control and exercise. The exercise group completed 12 weeks of aerobic exercise training. Aerobic exercise training significantly increased the antegrade shear rate and decreased the retrograde shear rate and brachial artery IMT. Moreover, changes in the brachial artery antegrade shear rate and the retrograde shear rate correlated with the change in brachial artery IMT. The results of the present study indicate that changes in brachial artery shear rate patterns may contribute to age- and aerobic exercise training-induced changes in brachial artery wall thickness.

Exercise training improves characteristics of exercise oscillatory ventilation in chronic heart failure

Background Exercise oscillatory ventilation in chronic heart failure has been suggested as a factor related to adverse cardiac events, aggravated prognosis and higher mortality. Exercise training is well known to affect exercise capacity and mechanisms of pathophysiology beneficially in chronic heart failure. Little is known, however, about the exercise training effects on characteristics of exercise oscillatory ventilation in chronic heart failure patients. Design and methods Twenty (out of 38) stable chronic heart failure patients exhibited exercise oscillatory ventilation (age 54 ± 11 years, peak oxygen uptake 15.0 ± 5.0 ml/kg per minute). Patients attended 36 sessions of high intensity interval exercise. All patients underwent cardiopulmonary exercise testing before and after the programme. Assessment of exercise oscillatory ventilation was based on the amplitude of cyclic fluctuations in breathing during rest and exercise. All values are mean ± SD. Results Exercise training reduced ( P < 0.05) the percentage of exercise oscillatory ventilation duration (79.0 ± 13.0 to 50.0 ± 25.0%), while average amplitude (5.2 ± 2.0 to 4.9 ± 1.6 L/minute) and length (44.0 ± 10.9 to 41.0 ± 6.7 seconds) did not change ( P > 0.05). Exercise oscillatory ventilation patients also increased exercise capacity ( P < 0.05). Conclusions A rehabilitation programme based on high intensity interval training improved exercise oscillatory ventilation observed in chronic heart failure patients, as well as cardiopulmonary efficiency and functional capacity.

Effect of neuromuscular stimulation and individualized rehabilitation on muscle strength in Intensive Care Unit survivors: A randomized trial

PURPOSE

Intensive Care Unit (ICU) survivors experience muscle weakness leading to restrictions in functional ability. Neuromuscular electrical stimulation (NMES) has been an alternative to exercise in critically ill patients. The aim of our study was to investigate its effects along with individualized rehabilitation on muscle strength of ICU survivors.

MATERIAL AND METHODS

Following ICU discharge, 128 patients (age: 53±16years) were randomly assigned to daily NMES sessions and individualized rehabilitation (NMES group) or to control group. Muscle strength was assessed by the Medical Research Council (MRC) score and hand grip at hospital discharge. Secondary outcomes were functional ability and hospital length of stay.

RESULTS

MRC, handgrip, functional status and hospital length of stay did not differ at hospital discharge between groups (p>0.05). ΔMRC% one and two weeks after ICU discharge tended to be higher in NMES group, while it was significant higher in NMES group of patients with ICU-acquired weakness at two weeks (p=0.05).

CONCLUSIONS

NMES and personalized physiotherapy in ICU survivors did not result in greater improvement of muscle strength and functional status at hospital discharge. However, in patients with ICU-aw NMES may be effective. The potential benefits of rehabilitation strategies should be explored in larger number of patients in future studies.

CLINICAL TRIAL REGISTRATION

www.Clinicaltrials.gov: NCT01717833.

Eficácia do treinamento resistido na melhora da capacidade funcional e na qualidade de vida de pacientes com insuficiência cardíaca: uma revisão sistemática e metanálise

RESUMO Avaliou-se a eficácia do treinamento resistido (TR) na melhoria da capacidade funcional (CF) e na qualidade de vida (QV) de pacientes com insuficiência cardíaca (IC). Uma busca eletrônica foi realizada em bancos de dados (PubMed, MEDLINE, Scopus, Web of Science, CINAHL, LILACS e Cochrane), sem restrições de linguagem ou ano de publicação, utilizando como descritores “heart failure”, “resistance training”, “exercise tolerance”, “quality of life”, “fatigue”, “dyspnea” e “muscle strength”. Foram incluídos ensaios clínicos, com amostra composta por indivíduos com IC, classe funcional I, II ou III da New York Heart Association; idade média <65 anos, sedentários, clinicamente estáveis e farmacologicamente otimizados; com fração de ejeção (FE) <45% do predito. A intervenção deveria ser o TR exclusivo. A descrição dos aspectos metodológicos pelo risco de viés e uma metanálise com uma análise por subgrupo foram executados. Sete estudos foram incluídos para análise qualitativa. O nível de concordância (índice kappa - k) entre os pesquisadores foi k=0,74. A maioria dos estudos que avalia CF e QV mostrou aumento no VO2 pico (pico de consumo de oxigênio) e nas pontuações finais dos questionários de QV para o grupo de intervenção. Os resultados de CF possibilitaram uma metanálise, exibindo um aumento final de 0,52 (0,17-0,87) mL.kg-1.min-1 (mililitros.quilograma-1.minuto-1) no VO2 pico depois do TR, com baixa heterogeneidade. Contudo, limitações estatísticas e diversidade de intervenções foram evidenciadas após a análise por subgrupos. As limitações encontradas nos estudos selecionados ainda não permitem considerar o TR eficaz na melhoria da CF e da QV em pacientes com IC.

Effects of 6 months of aerobic and resistance exercise training on carotid artery intima media thickness in overweight and obese older women

AIM

We studied the effects of exercise on carotid intima-media thickness, luminal diameter, and flow velocity in overweight and obese older women, and the associations between carotid parameters changes and other variables.

METHODS

A total of 41 overweight and obese older women (aged 65-77 years, fat mass percent ≥ 32%), who were divided into a control group (n = 20) and a supervised combined exercise group (n = 21). The 24-week combined exercise program (aerobic and resistance exercise) consisted of sessions 40-80 min in length 5 days per week under the supervision of an exercise specialist. Body composition, blood pressure, physical function and carotid variables were assessed. The differences in all variables, and the relative changes between baseline and 24 weeks' follow up were evaluated.

RESULTS

Carotid intima-media thickness, systolic carotid luminal diameter, peak systolic flow velocity and end diastolic flow velocity showed a significant group × time interaction. No interaction was observed for diastolic luminal diameter. In the exercise group, the change of carotid intima-media thickness was significantly associated with systolic blood pressure, maximal walking speed, 1-mile walking time and maximal oxygen uptake. Also, the change of peak systolic flow velocity was significantly associated with skeletal muscle mass, diastolic blood pressure and maximum walking speed.

CONCLUSIONS

Combined exercise can effectively improve carotid intima-media thickness in overweight and obese older women. In addition, exercise training increases the systolic carotid luminal diameter and flow velocity in older women. Therefore, regular combined exercise might help prevent atherosclerotic disease by improving the carotid artery. Geriatr Gerontol Int 2017; 17: 2304-2310.

Effect of short-term exercise intervention on cardiovascular functions and quality of life of chronic heart failure patients: A meta-analysis

OBJECTIVE

The purpose of this study was to comprehensively evaluate the effect of short-term exercise intervention on the cardiovascular functions and quality of life (QoL) of patients with chronic heart failure (CHF).

METHODS

This meta-analysis was analyzed using RevMan5.3 and Stata 13.0. The parameters of cardiovascular functions and QoL were assessed. Weighted mean differences and their corresponding 95% confidence intervals (CIs) were computed for continuous variables.

RESULTS

Data from 2533 CHF patients enrolled in 28 published studies of randomized controlled trials (RCTs) were collated. There were significant differences in VO2 max prior to and after exercise intervention in CHF patients who are 50-55 years old (5 RCTs; 95% CI, -4.86 to -2.29; I2 = 50.5%), 60-65 years old (10 RCTs; 95% CI, -2.66 to -2.04; I2 = 0%), and 69-75 years old (5 RCTs; 95% CI, -1.88 to -0.34; I2 = 38.5%). VO2 max was significantly increased by aerobic exercise (9 RCTs; 95% CI, -3.45 to -1.92; I2 = 37.7%) and combined aerobic resistance exercise (4 RCTs; 95% CI, -4.41 to -0.26; I2 = 76.6%). There were significant differences in cardiac output (n = 303; 95% CI, -0.25 to -0.02; I2 = 12%) and QoL (n = 299; 95% CI, 3.19 to 9.70; I2 = 17%) prior to and after short-term exercise.

CONCLUSION

Aerobic exercise and aerobic with resistance exercise can significantly improve the aerobic capacity of CHF patients, whereas resistance exercise cannot. The improvement in aerobic capacity caused by aerobic exercise and aerobic with resistance exercise decreases with age. Systolic blood pressure and ventricle structures and functions of CHF patients show no significant changes after the short-term exercise intervention.

The effects of resistance training on muscle strength, quality of life and aerobic capacity in patients with chronic heart failure - A meta-analysis

BACKGROUND

Resistance training (RT) has been utilised to target muscle dysfunction associated with Chronic Heart Failure (CHF). However, there is limited meta-analysis evidence to support its use as a standalone therapy. This meta-analysis examined the effects of RT on muscle strength (one repetition maximum, 1RM and Peak Torque), aerobic capacity (VO_2peak and 6min walk distance) and quality of life (QoL) in patients with CHF.

METHODS

We searched Medline, EMBASE, Cochrane and CINAHL for studies published up to July 2016, combining terms related to the population (eg, heart failure, CHF) with terms for the intervention (eg, resistance, strength training) and the outcomes (eg, QoL, VO₂peak_,strength, aerobic capacity).

RESULTS

Ten studies including 240 participants were included in our meta-analysis (aged 48-76years, Ejection Fraction 18-37%). Training duration ranged from 8 to 24weeks and intensity up to 80% of 1RM. RT increased 1RM (standardised change score=0.60; 95% Confidence Interval: 0.43, 0.77) but not strength measured via peak torque at 60°/s^-1 and 180°/s^-1. RT increased VO_2peak (CSMD: 2.71ml/kg/min; 1.96, 3.45) and QoL (CSMD: -5.71; -9.85, -1.56).

CONCLUSION

RT as a single intervention can increase muscle strength, aerobic capacity and QoL in patients with CHF and may offer an alternative approach, particularly for those unable to participate in aerobic training. The effect of RT on muscle strength is mainly during slow controlled movements and not during rapid movements. Older adults and patients with advanced CHF are underrepresented in RT trials and future studies should seek to optimise their inclusion.

Effects of 24-week resistance exercise training on carotid peak systolic and end diastolic flow velocity in healthy older adults

[Purpose] The aim of this study was to examine the effect of resistance exercise on carotid intima-media thickness, luminal diameter, peak systolic flow velocity, end diastolic flow velocity, and wall shear rate in healthy elderly men. [Subjects and Methods] Thirty healthy elderly men (age ≥65 years) were randomly divided into a control (n=15) and resistance exercise (n=15) groups. The 24-week exercise intervention consisted of 3 days of resistance exercise per week using an elastic band per week. Body composition, physical function, blood pressure, and carotid variables were measured at baseline and after 24 weeks. [Results] Body fat percent, skeletal muscle mass, systolic blood pressure, grip strength, arm curl, chair stand up, sit and reach, maximum walking speed, time up and go, and two-minute step test showed significant interaction. Peak systolic flow velocity, end diastolic flow velocity, and wall shear rate also showed significant interaction. [Conclusion] A 24-week resistance exercise program, using elastic bands, effectively improves carotid flow velocity and wall shear rate in healthy elderly men.

Dynamic Resistance Training as Stand-Alone Antihypertensive Lifestyle Therapy: A Meta-Analysis

Background

Aerobic exercise (AE) is recommended as first‐line antihypertensive lifestyle therapy based on strong evidence showing that it lowers blood pressure (BP) 5 to 7 mm Hg among adults with hypertension. Because of weaker evidence showing that dynamic resistance training (RT) reduces BP 2 to 3 mm Hg among adults with hypertension, it is recommended as adjuvant lifestyle therapy to AE training. Yet, existing evidence suggests that dynamic RT can lower BP as much or more than AE.

Methods and Results

We meta‐analyzed 64 controlled studies (71 interventions) to determine the efficacy of dynamic RT as stand‐alone antihypertensive therapy. Participants (N=2344) were white (57%), middle‐aged (47.2±19.0 years), and overweight (26.8±3.4 kg/m²) adults with prehypertension (126.7±10.3/76.8±8.7 mm Hg); 15% were on antihypertensive medication. Overall, moderate‐intensity dynamic RT was performed 2.8±0.6 days/week for 14.4±7.9 weeks and elicited small‐to‐moderate reductions in systolic BP (SBP; d₊=−0.31; 95% CIs, −0.43, −0.19; −3.0 mm Hg) and diastolic BP (DBP; d₊=−0.30; 95% CIs, −0.38, −0.18; −2.1 mm Hg) compared to controls (Ps<0.001). Greater BP reductions occurred among samples with higher resting SBP/DBP: ≈6/5 mm Hg for hypertension, ≈3/3 mm Hg for prehypertension, and ≈0/1 mm Hg for normal BP (Ps<0.023). Furthermore, nonwhite samples with hypertension experienced BP reductions that were approximately twice the magnitude of those previously reported following AE training (−14.3 mm Hg [95% CIs, −19.0, −9.4]/−10.3 mm Hg [95% CIs, −14.5, −6.2]).

Conclusions

Our results indicate that for nonwhite adult samples with hypertension, dynamic RT may elicit BP reductions that are comparable to or greater than those reportedly achieved with AE training. Dynamic RT should be further investigated as a viable stand‐alone therapeutic exercise option for adult populations with high BP.

Long Noncoding RNA-GAS5: A Novel Regulator of Hypertension-Induced Vascular Remodeling

Vascular remodeling is an important pathological feature of hypertension, leading to increased vascular resistance and reduced compliance. Endothelial cell (EC) and vascular smooth muscle cell (VSMC) dysfunction is involved in vascular remodeling. Long noncoding RNAs are potential regulators of EC and VSMC function. Herein, we determined whether long noncoding RNA-growth arrest-specific 5 (GAS5) is involved in hypertension-related vascular remodeling. We revealed that GAS5 knockdown aggravated hypertension-induced microvascular dysfunction as shown by increased retinal neovascularization and capillary leakage. GAS5 regulated the remodeling of arteries, including caudal arteries, carotid arteries, renal arteries, and thoracic arteries. GAS5 was mainly expressed in ECs and VSMCs, and its expression was significantly downregulated in hypertension. GAS5 knockdown affected endothelial activation, endothelial proliferation, VSMC phenotypic conversion, and EC-VSMC communication in vivo and in vitro. Mechanistically, GAS5 regulated EC and VSMC function through β-catenin signaling. This study identified GAS5 as a critical regulator in hypertension and demonstrated the potential of gene therapy and drug development for treating hypertension.

Comparing exercise training modalities in heart failure: A systematic review and meta-analysis

Exercise training (ET) is suggested to improve exercise capacity, prognosis, quality of life (QOL) and functional modifications of the heart in patients with heart failure (HF). However, it is not clear which modality is best. In order to assess the effectiveness of different ET modalities on prognostic cardiopulmonary exercise test (CPET) parameters, QOL and left ventricular remodeling, a systematic review and meta-analysis was performed. Randomized clinical trials (RCTs) were selected in three databases. The primary outcome data were peak oxygen uptake, ventilation over carbon dioxide slope, oxygen uptake efficiency slope, exercise oscillatory ventilation, rest and peak pulmonary end-tidal CO2. Secondary variables were QOL, left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD). Twenty RCTs (n=811) met the a priori stated inclusion criteria. Studies were categorized into four different groups: "interval training (IT1) versus combined interval and strength training (IT1S)" (n=156), "continuous training (CT1) versus combined continuous and strength training (CT1S)" (n=130), "interval training (IT2) versus continuous training (CT2)" (n=501) and "continuous training (CT3) versus strength training (S3)" (n=24). No significant random effects of exercise modality were revealed assessing the CPET parameters. There was a significant improvement in QOL applying CT1S (P<0.001). Comparing IT2 with CT2, LVEDD and LVEF were significantly improved favoring IT2 (P<0.001). There is some evidence to support that interval training is more effective to improve LVEF and LVEDD. The fact that patients with HF are actively involved in any kind of ET program seems sufficient to improve the prognosis, QOL and anatomic function.

Impact of traditional Greek dancing on jumping ability, muscular strength and lower limb endurance in cardiac rehabilitation programmes

AIMS

The objective of this study was to evaluate the effect of a training programme based on traditional Greek dance on the jumping ability, muscle strength and lower limb endurance in patients with chronic heart failure (CHF).

PATIENTS AND METHODS

Forty Greek patients with CHF graded as NYHA ⩽ II and aged 73.2±4.7 years were randomly divided into two groups. Group A ( n=20) participated in a three-month physical rehabilitation programme based on Greek traditional dances, whereas group B ( n=20) remained untrained and served as the control group. All patients were studied before and after the 12-week exercise training programme. At baseline and follow-up the exercise capacity of the patients was evaluated by the six-minute walking test, their lower extremity muscle strength was evaluated by an isokinetic dynamometer and their jumping ability by the Myotest-Pro test, which includes three types of jumps (plyometric, countermovement and squat jumps).

RESULTS

No significant difference was observed between the two groups at the baseline evaluation. At follow-up, group A showed significant improvements in walking distance calculated from the six-minute walking test (10.0% improvement; p<0.05), in lower limb strength (10.32% improvement; p<0.05), and in countermovement jump speed (6.9%; p<0.05) and squat jump speed (5.8%; p<0.05). Group A also increased their jump plyometry height by 13.86% ( p<0.05), their counter jump height by 10.68% ( p<0.05) and their squat jump height by 10.45% ( p<0.05). Group A had a 6.85% ( p<0.05) increased force of counter jump compared with group B.

CONCLUSION

The design and implementation of cardiac rehabilitation programmes using Greek traditional dances in patients with CHF are both safe and effective in improving lower limb function.

Effect of aliskiren on vascular remodelling in small retinal circulation

BACKGROUND

In hypertension, changes in small arterial structure are characterized by an increased wall-to-lumen ratio (WLR). These adaptive processes are modulated by the rennin-angiotensin system. It is unclear whether direct renin inhibitors exert protective effects on small arteries in hypertensive patients.

METHODS

In this double-blind, randomized, placebo-controlled study (http://www.clinicaltrials.gov: NCT01318395), 114 patients with primary hypertension were randomized to additional therapy with either placebo or aliskiren 300 mg for 8 weeks after 4 weeks of standardized open-label treatment with valsartan 320 mg (run-in phase). Parameter of arteriolar remodelling was WLR of retinal arterioles (80 - 140 μm) assessed noninvasively and in vivo by scanning laser Doppler flowmetry (Heidelberg Engineering, Germany). In addition, pulse wave analysis (SphygmoCor, AtCor Medical, Australia) and pulse pressure (PP) amplification were determined.

RESULTS

In the whole study population, no clear effect of additional therapy with aliskiren on vascular parameters was documented. When analyses were restricted to patients with vascular remodelling, defined by a median of WLR more than 0.3326 (n = 57), WLR was reduced after 8 weeks by the treatment with aliskiren compared with placebo (-0.044 ± 0.07 versus 0.0043 ± 0.07, P = 0.015). Consistently, after 8 weeks of on-top treatment with aliskiren, there was an improvement of PP amplification compared with placebo (0.025 ± 0.07 versus -0.034 ± 0.08, P = 0.013), indicative of less stiff arteries in the peripheral circulation.

CONCLUSION

Thus, our data indicate that treatment with aliskiren, given on top of valsartan therapy, improves altered vascular remodelling in hypertensive patients.

Arterial adaptations to training among first time marathoners

BACKGROUND

Exercise training favorably alters arterial anatomy in trained limbs, though the simultaneous effects on passively trained arteries are unclear. Thus, brachial (non-trained limb), popliteal (trained limb) and carotid total wall thickness (TWT), wall-to-lumen ratios (W:L), intima-media thickness (IMT) and lumen diameters (LD) were compared between experimental (n = 14) and control (n = 11) participants before and after the experimental participants participated in marathon training.

METHODS

Arterial dimensions were measured with B-mode ultrasonography. Initial and final testing of VO2max and running speed at 3.5 mmol lactate were measured in the experimental group.

RESULTS

VO2max was unchanged by training, but running speed at 3.5 mmol lactate increased by 5 % (p = .008). Time by group interactions were observed for the brachial and popliteal measures (p < 0.05), but not the carotid. No changes were observed in the control group. Prior to the intervention the experimental group had larger LD in the brachial (p = .002) and popliteal arteries (p = .007) than controls; no other pre-testing differences were found. Following training, TWT declined in the brachial (pre = .99 ± .16 mm; post = .84 ± .10 mm; p = .007) and popliteal (pre = .96 ± .09 mm; post = .86 ± .11 mm; p = .005) arteries, characterized by a 0.07 mm decrease in brachial IMT (p = .032) and a non-significant 0.03 mm reduction in popliteal IMT. LD increased in the brachial (pre = 3.38 ± .35 mm; post = 3.57 ± .41 mm; p = .015) and popliteal (pre = 4.73 ± .48 mm; post = 5.11 ± .72 mm; p = .002) arteries.

CONCLUSIONS

These data suggest that exercise-induced alterations in arterial dimensions occur in trained and non-trained limbs, and that adaptations may be dose dependent.

The influence of training characteristics on the effect of aerobic exercise training in patients with chronic heart failure: A meta-regression analysis

Although aerobic exercise training has shown to be an effective treatment for chronic heart failure patients, there has been a debate about the design of training programs and which training characteristics are the strongest determinants of improvement in exercise capacity. Therefore, we performed a meta-regression analysis to determine a ranking of the individual effect of the training characteristics on the improvement in exercise capacity of an aerobic exercise training program in chronic heart failure patients. We focused on four training characteristics; session frequency, session duration, training intensity and program length, and their product; total energy expenditure. A systematic literature search was performed for randomized controlled trials comparing continuous aerobic exercise training with usual care. Seventeen unique articles were included in our analysis. Total energy expenditure appeared the only training characteristic with a significant effect on improvement in exercise capacity. However, the results were strongly dominated by one trial (HF-action trial), accounting for 90% of the total patient population and showing controversial results compared to other studies. A repeated analysis excluding the HF-action trial confirmed that the increase in exercise capacity is primarily determined by total energy expenditure, followed by session frequency, session duration and session intensity. These results suggest that the design of a training program requires high total energy expenditure as a main goal. Increases in training frequency and session duration appear to yield the largest improvement in exercise capacity.

Exercise modalities and endothelial function: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Regular exercise is associated with enhanced nitric oxide (NO) bioavailability. Flow-mediated dilation (FMD) is used widely to assess endothelial function (EF) and NO release.

OBJECTIVES

The aims of this systematic review and meta-analysis were to (i) investigate the effect of exercise modalities (aerobic, resistance or combined) on FMD; and (ii) determine which exercise and participant characteristics are most effective in improving FMD.

METHODS

We searched the MEDLINE, Embase, Cochrane Library, and Scopus databases for studies that met the following criteria: (i) randomized controlled trials of exercise with comparative non-exercise, usual care or sedentary groups; (ii) duration of exercise intervention ≥4 weeks; (iii) age ≥18 years; and (iv) EF measured by FMD before and after the intervention. Weighted mean differences (WMDs) with 95% confidence interval were entered into a random effect model to estimate the pooled effect of the exercise interventions.

RESULTS

All exercise modalities enhanced EF significantly: aerobic (WMD 2.79, 95% CI 2.12-3.45, p = 0.0001), resistance (WMD 2.52, 95% CI 1.11-3.93, p = 0.0001) and combined (WMD 2.07, 95% CI 0.70-3.44, p = 0.003). A dose-response relationship was observed between aerobic exercise intensity and improvement in EF. A 2 metabolic equivalents (MET) increase in absolute exercise intensity or a 10% increase in relative exercise intensity resulted in a 1% unit improvement in FMD. There was a positive relationship between frequency of resistance exercise sessions and improvement in EF (β 1.14, CI 0.16-2.12, p = 0.027).

CONCLUSIONS

All exercise modalities improve EF significantly and there was a significant, positive relationship between aerobic exercise intensity and EF. Greater frequency, rather than intensity, of resistance exercise training enhanced EF.

Influence of aerobic training on the reduced vasoconstriction to angiotensin II in rats exposed to intrauterine growth restriction: possible role of oxidative stress and AT2 receptor of angiotensin II

Intrauterine growth restriction (IUGR) is associated with impaired vascular function, which contributes to the increased incidence of chronic disease. The aim of this study was to investigate whether aerobic training improves AngII-induced vasoconstriction in IUGR rats. Moreover, we assess the role of superoxide dismutase (SOD) isoforms and NADPH oxidase-derived superoxide anions in this improvement. Female Wistar rats were randomly divided into two groups on day 1 of pregnancy. A control group was fed standard chow ad libitum, and a restricted group was fed 50% of the ad libitum intake throughout gestation. At 8 weeks of age, male offspring from both groups were randomly assigned to 4 experimental groups: sedentary control (SC), trained control (TC), sedentary restricted (SRT), and trained restricted (TRT). The training protocol was performed on a treadmill and consisted of a continuous 60-min session 5 days/week for 10 weeks. Following aerobic training, concentration–response curves to AngII were obtained in endothelium-intact aortic rings. Protein expression of SOD isoforms, AngII receptors and the NADPH oxidase component p47^phox was assessed by Western blot analysis. The dihydroethidium was used to evaluate the in situ superoxide levels under basal conditions or in the presence of apocynin, losartan or PD 123,319. Our results indicate that aerobic training can prevent IUGR-associated increases in AngII-dependent vasoconstriction and can restore basal superoxide levels in the aortic rings of TRT rats. Moreover, we observed that aerobic training normalized the increased p47^phox protein expression and increased MnSOD and AT₂ receptor protein expression in thoracic aortas of SRT rats. In summary, aerobic training can result in an upregulation of antioxidant defense by improved of MnSOD expression and attenuation of NADPH oxidase component p47^phox. These effects are accompanied by increased expression of AT₂ receptor, which provide positive effects against Ang II–induced superoxide generation, resulting in attenuation of AngII-induced vasoconstriction.

Time-course of vascular adaptations during 8 weeks of exercise training in subjects with type 2 diabetes and middle-aged controls

PURPOSE

Exercise training in healthy volunteers rapidly improves vascular function, preceding structural remodelling. No study examined the time-course of such adaptations in subjects with a priori endothelial dysfunction.

METHODS

We examined brachial artery endothelial and smooth muscle function using flow-mediated dilation (FMD) and glyceryl trinitrate (GTN) administration in 13 type 2 diabetes patients (59 ± 6 years) and 10 healthy subjects (58 ± 7 years) before, during (2-weekly) and after an 8-week training programme. Arterial structure was assessed via peak blood flow and artery diameter.

RESULTS

Training increased peak oxygen uptake (P = 0.03), comparable between groups (P = 0.276). We observed a similar impact of training on brachial artery vasomotor function across the training period in diabetes patients and controls (FMD/GTN-ratio), with a higher FMD/GTN-ratio at 2, 6 and 8 weeks (P = 0.036). Artery diameter, peak blood flow or peak diameter had not changed after training.

CONCLUSION

Training leads to rapid improvement in brachial artery vascular function in diabetes patients and controls. In contrast to previous observations in healthy young subjects, the increase in function was preserved after 8 weeks of training in middle-aged diabetes patients and controls, suggesting a different time-course in vascular adaptations in subjects with endothelial dysfunction.

Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors

The objectives of our study were to examine 1) the proportion of responders and nonresponders to exercise training in terms of vascular function; 2) a priori factors related to exercise training-induced changes in conduit artery function, and 3) the contribution of traditional cardiovascular risk factors to exercise-induced changes in artery function. We pooled data from our laboratories involving 182 subjects who underwent supervised, large-muscle group, endurance-type exercise training interventions with pre-/posttraining measures of flow-mediated dilation (FMD%) to assess artery function. All studies adopted an identical FMD protocol (5-min ischemia, distal cuff inflation), contemporary echo-Doppler methodology, and observer-independent automated analysis. Linear regression analysis was used to identify factors contributing to changes in FMD%. We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P < 0.001). Training-induced increase in FMD% was predicted by lower body weight (β = -0.212), lower baseline FMD% (β = -0.469), lower training frequency (β = -0.256), and longer training duration (β = 0.367) (combined: P < 0.001, r = 0.63). With the exception of a modest correlation with total cholesterol (r = -0.243, P < 0.01), changes in traditional cardiovascular risk factors were not significantly related to changes in FMD% (P > 0.05). In conclusion, we found that, while some subjects do not demonstrate increases following exercise training, improvement in FMD% is present in those with lower pretraining body weight and endothelial function. Moreover, exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors.

Low-flow mediated constriction: the yin to FMD's yang?

Given the prevalence of cardiovascular disease (CVD), early detection is crucial. Although traditional cardiovascular risk factors relate to future CVD, the predictive value of these risk factors can be relatively limited. Contemporary scientific attention has focused on alternative direct measures of arterial function. Based on the ability of the endothelium to acutely dilate in response to an increase in flow, 'flow mediated dilation' (FMD) was introduced approximately 20 years ago and is now an established non-invasive index of endothelial function predictive of future cardiovascular events. Recently, 'low-flow mediated constriction' (L-FMC) has been proposed as a complementary addition to FMD. The technique is based on the constrictor response to decreased flow and is claimed to improve the sensitivity and specificity of FMD. The aim of this review is to examine literature pertaining to this novel technique and to provide insight into the potential use of L-FMC in future research.

Can exercise training rescue the adverse cardiometabolic effects of low birth weight and prematurity?

Being born preterm and/or small for gestational age are well-established risk factors for cardiometabolic disease in adulthood. Physical activity has the potential to mitigate against the detrimental cardiometabolic effects of low birth weight from two perspectives: (i) maternal exercise prior to and during pregnancy; and (ii) exercise during childhood or adulthood for those born small or prematurely. Evidence from epidemiological birth cohort studies suggests that the effects of moderate-intensity physical activity during pregnancy on mean birth weight are small, but reduce the risk of either high or low birth weight infants. In contrast, vigorous and/or high-intensity exercise during pregnancy has been associated with reduced birth weight. In childhood and adolescence, exercise ability is compromised in extremely low birth weight individuals (< 1000 g), but only marginally reduced in those of very low to low birth weight (1000-2500 g). Epidemiological studies show that the association between birth weight and metabolic disease is lost in physically fit individuals and, consistently, that the association between low birth weight and metabolic syndrome is accentuated in unfit individuals. Physical activity intervention studies indicate that most cardiometabolic risk factors respond to exercise in a protective manner, independent of birth weight. The mechanisms by which exercise may protect low birth weight individuals include restoration of muscle mass, reduced adiposity and enhanced β-cell mass and function, as well as effects on both aerobic and anaerobic muscle metabolism, including substrate utilization and mitochondrial function. Vascular and cardiac adaptations are also likely important, but are less well studied.

Local and systemic effects of leg cycling training on arterial wall thickness in healthy humans

Exercise training is associated with direct effects on conduit artery function and structure. Cross-sectional studies suggest the presence of systemic changes in wall thickness as a result of exercise in healthy subjects, but no previous study has examined this question in humans undertaking exercise training.

OBJECTIVE

To examine the change in superficial femoral (SFA, i.e. local effect) and carotid (CA, i.e. systemic effect) artery wall thickness across 8 weeks of lower limb cycle training in healthy young men.

METHODS

Fourteen healthy young male subjects were assigned to an 8-week training study of cycling exercise (n = 9) or a control period (n = 5). Before, during (2, 4 and 6 weeks) and after training, SFA and CA wall thickness was examined using automated edge-detection of high resolution ultrasound images. We also measured resting diameter and calculated the wall:lumen(W:L)-ratio.

RESULTS

Exercise training did not alter CA or SFA baseline diameter (P = 0.14), but was associated with gradual, consistent and significant decreases in wall thickness and W:L-ratio in both the CA and SFA (P < 0.001 and 0.002, respectively). Two-way ANOVA revealed a comparable magnitude of decrease in wall thickness and W:L-ratio in both arteries across the 8-week period (interaction-effect; P = 0.29 and 0.12, respectively). No changes in artery diameter, wall thickness or W:L-ratio were apparent in controls (0.82, 0.38 and 0.52, respectively).

CONCLUSION

We found that cycle exercise training in healthy young individuals is associated with modest, but significant, decreases in wall thickness in the superficial femoral and carotid arteries. These findings suggest that exercise training causes systemic adaptation of the arterial wall in healthy young subjects.

Comparison of brachial artery wall thickness versus endothelial function to predict late cardiovascular events in patients undergoing elective coronary angiography

An increased brachial artery intima media thickness (BA-IMT) has been shown to be of prognostic value. Conflicting prognostic data have been reported for brachial artery flow-mediated vasodilation (BA-FMD), and the longest evaluated follow-up period to date is 5.5 years. We sought to investigate the very late prognostic value of BA-IMT and BA-FMD in 396 consecutive patients (age 54 ± 9 years) admitted for invasive evaluation of chest pain. BA-IMT and BA-FMD were measured using high-resolution ultrasonography. The patients were divided according to the median BA-IMT (0.37 mm) and median BA-FMD (7.6%). After a mean follow-up of 141 ± 12 months, cardiovascular events were documented. More cardiovascular events were found in patients with an increased BA-IMT (50 vs 78 events, p = 0.003). When the groups were compared according to the median BA-FMD, no differences in the number of events were documented (70 vs 75 events, p = 0.60). On multivariate Cox regression analysis, including age, number of risk factors, BA diameter, presence of coronary artery disease, BA-FMD, and BA-IMT, only the presence of coronary artery disease and BA-IMT remained significantly associated with outcome. In conclusion, BA-IMT, but not BA-FMD, predicted cardiovascular events and cardiovascular death with ≤12 years of follow-up in patients undergoing an invasive evaluation of chest pain. Our results represent, by far, the longest follow-up of BA-IMT and peripheral endothelial function testing compared with previously reported data.

Resistance versus aerobic exercise training in chronic heart failure

It is now accepted that exercise training is a safe and effective therapeutic intervention to improve clinical status, functional capacity, and quality of life in people with chronic heart failure (CHF). Nevertheless, this therapeutic modality remains underprescribed and underutilized. Both aerobic and resistance training improve exercise capacity and may partially reverse some of the cardiac, vascular, and skeletal muscle abnormalities in individuals with CHF. Aerobic training has more beneficial effects on aerobic power (peak oxygen consumption) and cardiac structure and function than resistance exercise training, while the latter is more effective for increasing muscle strength and endurance and promoting favorable arterial remodeling. Combined aerobic and resistance training is the preferred exercise intervention to reverse or attenuate the loss of muscle mass and improve exercise and functional capacity, muscle strength, and quality of life in individuals with CHF. The challenge now is to translate these research findings into clinical practice.

A prospective randomized longitudinal study involving 6 months of endurance or resistance exercise. Conduit artery adaptation in humans

Abstract  This randomized trial evaluated the impact of different exercise training modalities on the function and size of conduit arteries in healthy volunteers. Young (27 ± 5 years) healthy male subjects were randomized to undertake 6 months of either endurance training (ET; n = 10) or resistance training (RT; n = 13). High-resolution ultrasound was used to determine brachial, femoral and carotid artery diameter and wall thickness (IMT) and femoral and brachial flow-mediated dilatation (FMD) and glyceryl trinitrate (GTN)-mediated dilatation. Improvements in peak oxygen uptake occurred with ET (from 3.6 ± 0.7 to 3.8 ± 0.6 l min(-1), P = 0.024) but not RT. Upper body muscular strength increased following RT (from 57.8 ± 17.7 to 69.0 ± 19.5 kg, P < 0.001), but not ET. Both groups exhibited increases in lean body mass (ET, 1.4 ± 1.8 kg and RT, 2.3 ± 1.3 kg, P < 0.05). Resistance training increased brachial artery resting diameter (from 3.8 ± 0.5 to 4.1 ± 0.4 mm, P < 0.05), peak FMD diameter (+0.2 ± 0.2 mm, P < 0.05) and GTN-mediated diameter (+0.3 ± 0.3 mm, P < 0.01), as well as brachial FMD (from 5.1 ± 2.2 to 7.0 ± 3.9%, P < 0.05). No improvements in any brachial parameters were observed following ET. Conversely, ET increased femoral artery resting diameter (from 6.2 ± 0.7 to 6.4 ± 0.6 mm, P < 0.05), peak FMD diameter (+0.4 ± 0.4 mm, P < 0.05) and GTN-induced diameter (+0.3 ± 0.3 mm, P < 0.05), as well as femoral FMD-to-GTN ratio (from 0.6 ± 0.3 to 1.1 ± 0.8, P < 0.05). Resistance training did not induce changes in femoral artery parameters. Carotid artery IMT decreased in response to both forms of training. These findings indicate that 6 months of supervised exercise training induced changes in brachial and femoral artery size and function and decreased carotid artery IMT. These impacts of both RT and ET would be expected to translate to decreased cardiovascular risk.

Effect of resistance training on biomarkers of vascular function and oxidative stress in young African-American and Caucasian men

African Americans (AA) have an earlier onset of hypertension and a different vascular profile than their Caucasian (Cau) peers. Research suggests that biological mediators of vascular inflammation are different among these groups in hypertensive populations. Resistance training (RT) is an important exercise modality that improves the vascular profile of young AA men. We examined the role of RT on biomarkers of vascular function and oxidative stress in body mass index-matched AA and Cau men. RT for 6 weeks elicited significant changes in circulating matrix metalloprotease-9 (MMP-9) and 8-Isoprostane (8-IsoP) in young AA men (n=14, AA; n=18, Cau; 18-35 years). MMP-9 was lower and decreased in AA (pre: P=0.02; post: P<0.001) and a time × group interaction for MMP-9 (F(1, 30)=4.81; P=0.036) and 8-IsoP (F(1, 24)=7.09; P=0.014) was detected. 8-IsoP decreased in AA (P=0.026) but did not change in Cau (P=0.309). Notably, the increase in strength (1-repetition maximum (1-RM)) was correlated with the decrease in MMP-9 (r=-0.398; P=0.022). Furthermore, these adaptations were independent of any improvement in cardiorespiratory fitness. We demonstrate that RT effectively reduces matrix remodeling proteins and oxidative stress in young AA men. Increasing strength may be beneficial for improving vascular health and offsetting novel cardiovascular risk factors of hypertension in young AA men.

Conduit diameter and wall remodeling in elite athletes and spinal cord injury

PURPOSE

This study aimed to investigate localized and systemic effects of chronic exercise and inactivity on conduit artery remodeling in humans.

METHODS

We recruited elite athletes engaged in predominantly lower limb (LL runners/cyclists, n = 10) or upper limb (UL canoe paddlers, n = 12) exercise and matched able-bodied, recreationally active, controls (C, n = 16). We also studied wheelchair controls (spinal cord injury, n = 9) and athletes (spinal cord injury, n = 1; spina bifida, n = 4). Carotid, brachial, and superficial femoral (SF) artery diameter and wall thickness were assessed using high-resolution ultrasound.

RESULTS

Brachial diameters were significantly larger in UL and wheelchair users (athletes and controls) compared with C (both P < 0.05). SF artery diameter in wheelchair controls was significantly smaller compared with the other groups, with LL athletes having significantly greater lumen diameter than controls (both P < 0.05). In all arteries, a lower wall thickness was found in able-bodied athletes compared with C, including wheelchair athletes compared with wheelchair controls (P < 0.001). In the SF artery, wall-to-lumen-ratio was significantly lower in able-bodied athletes and higher in wheelchair controls compared with able-bodied controls (P < 0.001). In the brachial and carotid arteries, able-bodied and wheelchair athletes demonstrated lower wall-to-lumen-ratio than less active wheelchair controls and able-bodied controls (P < 0.001).

CONCLUSIONS

These findings suggest that remodeling of the arterial wall occurs systemically in response to exercise training and is unrelated to exercise type in humans. Conversely, localized effects are evident with respect to the effect of exercise on arterial diameter. These findings have implications for our understanding of the effects of exercise on arterial structure and function in humans.