Endurance Exercise Training Improves Heart Rate Recovery in Patients with COPD

Effect of pulmonary rehabilitation on heart rate recovery in adult individuals with asthma or chronic obstructive pulmonary disease

Introduction: Heart rate recovery (HRR) after exercise is a marker of disease severity and prognosis in cardiovascular and respiratory disorders. More than 30% of adult individuals with asthma may show a slow HRR. Pulmonary rehabilitation improves exercise capacity in individuals with asthma or chronic obstructive pulmonary disease (COPD).

Aim: The study aimed to evaluate the effect of pulmonary rehabilitation on HRR in individuals with asthma as compared to those with COPD.

Methods: Retrospective analysis of HRR one minute after the six-minute walking test (6MWT) was performed before and after an exercise training program. The COPD Assessment Test (CAT), Barthel Index-Dyspnea (BI-D), Medical Research Council (MRC) score for dyspnea, and the Five-Times-Sit-to-Stand test (5STS) were also assessed as secondary outcome measures.

Results: Slow HRR prevalence was significantly lower in individuals with asthma than with COPD (29.1 vs. 46.7%, respectively: p = 0.003). Post-program HRR did not change in more than 70% of individuals in either population and improved in 16% of both populations, whereas it actually worsened in 12 and 10% of individuals with asthma and COPD, respectively. The outcome measures significantly improved in both populations, irrespective of baseline HRR.

Conclusion: In individuals with asthma or COPD, exercise training does not significantly improve HRR.

Effect of Endurance Training in COPD Patients Undergoing Pulmonary Rehabilitation: A Meta-Analysis

Background

The efficacy of endurance training (ET) on patients with chronic obstructive pulmonary disease (COPD) has been controversial. This study was aimed at meta-analyzing the effect of ET in COPD patients undergoing pulmonary rehabilitation.

Methods

The literature retrieval was performed in databases to screen relevant literature. Inclusion criteria were as follows: (1) subjects—COPD patients; (2) inclusion of interventional and control groups; (3) intervention measures—the interventional group received whole-body ET and other lung rehabilitation training, while the control group did not receive intervention or other lung rehabilitation training; (4) outcome indicators which included at least one of the following—6MWD, modified Medical Research Council questionnaire (mMRC), and COPD Assessment Test (CAT); and (5) study type—randomized controlled trials (RCTs). The Cochrane risk-of-bias tool was used to assess the risk of bias. The chi-square test was used to evaluate the magnitude of heterogeneity. Subgroup analysis was used to explore the source of heterogeneity. A funnel plot and Egger's test were used to evaluate publication bias.

Results

The 6MWD in the ET group was significantly higher than that in the control group (MD = 47.20, 95% CI [28.60, 65.79], P < 0.00001). Significant heterogeneity (P < 0.00001, I² = 76%) without publication bias (P > 0.05) was noted. Subgroup analysis showed that the 6MWD of the ET group was significantly larger than that of the control group without heterogeneity (P = 0.63, I² = 0%; P = 0.59, I² = 0%) in both the no training subgroup (MD = 79.26, 95% CI [72.69, 85.82], P < 0.00001) and other rehabilitation training group (MD = 23.64, 95% CI [6.70, 40.57], P = 0.006). The mMRC score (MD = −0.72, 95% CI [-1.09, -0.34], P = 0.002) and CAT (MD = −6.07, 95% CI [-7.28, -4.87], P < 0.00001) of the ET group were significantly lower than those of the control group. There was no heterogeneity (P = 0.32, I² = 15%; P = 0.16, I² = 41%).

Conclusion

ET can improve patients' motor function and reduce dyspnea. ET might be incorporated as an important part of lung rehabilitation training.

Heart rate recovery in adult individuals with asthma

Slow heart rate recovery (HRR) after exercise is a predictor of overall mortality in individuals with and without cardiovascular or respiratory disorders. No data on adults with asthma are available. The purpose of the study is to evaluate the prevalence of slow HRR in these individuals as compared with those with chronic obstructive pulmonary disease (COPD). We performed a retrospective analysis of baseline characteristics and physiological response to the six-minute walking distance test of stable individuals with asthma or COPD. Slow HRR was defined as HRpeak - HR at 1 minute after end exercise <12 bpm. Individuals with asthma walked significantly longer (median (IQR): 455 (385-512) vs 427 (345-485) meters; p=0.005) with a lower prevalence of slow HRR (30.3% vs 49.0%, respectively: p<0.001) than those with COPD. Individuals with asthma and slow HRR were older and walked less than those with normal HRR, without any difference in airway obstruction or in disease severity. Multivariate analysis showed that only the difference HRpeak - baseline HR (∆HR), was a predictor of slow HRR in both groups. More than 30% of adult individuals with asthma may show slow HRR. Only exercise ∆HR but no baseline characteristic seems to predict the occurrence of slow HRR.

Effect of Oxidative Stress on Diaphragm Dysfunction and Exercise Intervention in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) can cause extrapulmonary injury such as diaphragm dysfunction. Oxidative stress is one of the main factors causing diaphragm dysfunction in COPD. Exercise plays a positive role in the prevention and treatment of diaphragm dysfunction in COPD, and the changes in diaphragm structure and function induced by exercise are closely related to the regulation of oxidative stress. Therefore, on the basis of the review of oxidative stress and the changes in diaphragm structure and function in COPD, this article analyzed the effects of exercise on oxidative stress and diaphragm dysfunction in COPD and explored the possible mechanism by which exercise improves oxidative stress. Studies have found that diaphragm dysfunction in COPD includes the decline of muscle strength, endurance, and activity. Oxidative stress mainly affects the structure and function of the diaphragm in COPD through protein oxidation, protease activation and calcium sensitivity reduction. The effects of exercise on oxidative stress level and diaphragm dysfunction may differ depending on the intensity, duration, and style of exercise. The mechanism of exercise on oxidative stress in the diaphragm of COPD may include improving antioxidant capacity, reducing oxidase activity and improving mitochondrial function.

Physical activity and cardiac autonomic dysfunction in patients with chronic obstructive pulmonary disease: a cross-sectional analysis

BACKGROUND

The cardiac autonomic function in patients with chronic obstructive pulmonary disease (COPD) has been poorly studied.

OBJECTIVES

We aimed to 1) describe the cardiac autonomic function assessed by heart rate recovery (HRR) and chronotropic response (CR) during a 6-min walk test (6MWT) and afterward and 2) estimate the association of physical activity with HRR and CR in COPD patients.

METHODS

This cross-sectional analysis included 320 patients with mild to very severe COPD. Physical activity (steps, time in any/moderate-to-vigorous/vigorous physical activity, intensity and sedentary time) was measured during 1 week by accelerometer. CR and HRR were measured during a 6MWT and 5 min after, respectively, and their association with physical activity parameters was estimated by multivariable linear regression models.

RESULTS

Patients were 82% male and had a mean (SD) age 68 (8) years, post-bronchodilator FEV1 57 (18) % predicted, and walked a mean of 7716 (4139) steps/day. HRR was slow until 5 min after the 6MWT; the mean (SD) was 15 (10), 22 (11), 25 (12), 25 (12) and 27 (12) bpm after 1, 2, 3, 4 and 5 min, respectively). The mean CR was 35% (16). After adjusting for relevant confounders, time in vigorous physical activity was significantly associated with a fast decrease in HRR (p=0.044) and an increase in CR (p=0.021). We found no independent association for other physical activity parameters.

CONCLUSION

A cardiac autonomic dysfunction is present in patients with mild to very severe COPD and is inversely related to the practice of vigorous physical activity.

Effect of different doses of supervised aerobic exercise on heart rate recovery in inactive adults who are overweight or obese: results from E-MECHANIC

PURPOSE

Heart rate recovery (HRR) after exercise is an independent risk factor for cardiovascular disease and mortality. Regular aerobic exercise can improve HRR, yet little is known regarding the dose necessary to promote increases. The aim was to assess the impact of different doses of vigorous-intensity aerobic exercise on HRR in individuals with overweight/obesity.

METHODS

Data from 137 sedentary adults with overweight/obesity from E-MECHANIC were analyzed. Participants were randomized to either a moderate-dose exercise group (8 kcal/kg body weight/week; KKW), a high-dose exercise group (20 KKW), or a non-exercise control group. HRR was defined as the difference between peak heart rate (HR) during a graded exercise test and the HR after exactly 1 min of active recovery at 1.5 mph and level grade.

RESULTS

Change in HRR did not differ significantly by exercise group; therefore, the data from both exercise groups were combined. The combined exercise group showed an improvement in HRR of 2.7 bpm (95% CI 0.1, 5.4; p = 0.04) compared to the control group. Those participants who lost more weight during the intervention (non-compensators) increased HRR by 6.2 bpm (95% CI 2.8, 9.5; p < 0.01) compared to those who lost less weight (compensators). Multiple linear regression models indicated that improvements in HRR are independently associated with increases in VO_2peak (β = 0.4; 95% CI 0.1, 0.7; p = 0.04) but also influenced by concomitant weight loss (β = 0.6; 95% CI 0.2, 1.1; p = 0.01).

CONCLUSION

Exercise-induced improvements in 1-min HRR are likely due to increases in cardiorespiratory fitness as well as concomitant weight loss.

Heart rate recovery is associated with ventilatory constraints and excess ventilation during exercise in patients with chronic obstructive pulmonary disease

Background Heart rate recovery delay is a marker of cardiac autonomic dysfunction. In chronic obstructive pulmonary disease patients, the ventilatory response to exercise during incremental cardiopulmonary exercise test may add information about dynamic hyperinflation by low values of inspiratory capacity/total lung capacity ratio (at peak) and excess ventilation by the slope of minute ventilation to carbon dioxide output ratio (V_E/V_{CO2 slope}). We aimed to assess if the ventilatory response to exercise might be a determinant for heart rate recovery delay. Design An observational, prospective study. Methods Anthropometric characteristics, lung function and cardiopulmonary exercise test data were recorded in chronic obstructive pulmonary disease outpatients. A cut-off of heart rate recovery of 12 or more beats was used to define heart rate recovery delay. Results Of 254 patients enrolled, 156 (61%) showed heart rate recovery delay. As compared to patients with normal heart rate recovery, patients with delay were older, with a worse lung function and with lower values of peak oxygen uptake, maximal workload, oxygen pulse at rest and at peak, and inspiratory capacity/total lung capacity at peak. Conversely, V_E/V_{CO2 slope} and dyspnoea and leg fatigue perception at peak were higher in patients with heart rate recovery delay. In the multivariate regression model adjusted for age, sex, fat-free mass, heart rate at rest and use of β-blockers, we found that inspiratory capacity/total lung capacity at peak (<0.25) (odds ratio 2.61; P = 0.007) and V_E/V_{CO2 slope} (>32) (odds ratio 2.26; P = 0.018) predict the risk of heart rate recovery delay. Conclusions In chronic obstructive pulmonary disease outpatients, heart rate recovery is associated with dynamic hyperinflation and excess ventilation during exercise.

Exercise assessments and trainings of pulmonary rehabilitation in COPD: a literature review

Skeletal muscle dysfunction leads to reduction in activity in patients with COPD. As an essential part of the management of COPD, pulmonary rehabilitation (PR) alleviates dyspnea and fatigue, improves exercise tolerance and health-related quality of life, and reduces hospital admissions and mortality for COPD patients. Exercise is the key component of PR, which is composed of exercise assessment and training therapy. To evaluate PR’s application in clinical practice, this article summarizes the common methods of exercise measurement and exercise training for patients with COPD. Exercise assessments should calculate patients’ symptoms, endurance, strength, and health-related quality of life. After calculation, detailed exercise therapies should be developed, which may involve endurance, strength, and respiratory training. The detailed exercise training of each modality is mentioned in this review. Although various methods and therapies of PR have been used in COPD patients, developing an individualized exercise training prescription is the target. More studies are warranted to support the evidence and examine the effects of long-term benefits of exercise training for patients with COPD in each stage.

Autonomic symptoms in patients with moderate and severe chronic obstructive pulmonary disease

OBJECTIVES

A synoptic description of the autonomic symptoms profile (ASP) of patients with COPD is not available. Therefore, we aimed to provide an overview of autonomic symptoms and its associates in COPD.

METHODS

We evaluated 89 subjects with COPD (65 ± 7.3 years; 66 males; GOLD II-IV) with an equal number of age- and sex-matched control subjects by means of the composite autonomic symptom score (COMPASS 31) questionnaire, which assesses autonomic symptoms across six domains (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, urinary and pupillomotor). Lung function, medication use and health status variables (quality of life: physical/mental component summary [PCS/MCS], fatigue, anxiety, depression and dyspnea levels) were also assessed.

RESULTS

Compared to controls, all subjects with COPD reported significantly higher orthostatic intolerance, secretomotor and total autonomic symptom scores (p < .05). Additionally, subjects with moderate COPD also reported significantly higher scores for vasomotor, gastrointestinal, urinary and pupillomotor symptoms compared to controls (p < .05). Nevertheless, these symptoms were comparable between the moderate and severe COPD subgroups (p > .05). The COPD subjects had poorer health status compared to controls as exhibited by significantly higher scores for depression, anxiety, fatigue and dyspnea, and lower scores values for PCS and MCS scores (p < .05). These health status variables were mildly associated with autonomic symptoms (0.214 ≤ r ≥ 0.421; p < .05), but not with demographic and lung function (p > .05). The MCS was the only significant predictor of total autonomic symptoms score in COPD (p = 0.001; β = -0.430).

CONCLUSION

Autonomic symptoms are present in all domains of the COMPASS-31 in COPD, irrespective of disease severity and demographic variables. Autonomic symptoms in COPD were mainly influenced by poor mental health.

Early-Phase Recovery of Cardiorespiratory Measurements after Maximal Cardiopulmonary Exercise Testing in Patients with Chronic Obstructive Pulmonary Disease

Background. This study investigated respiratory gas exchanges and heart rate (HR) kinetics during early-phase recovery after a maximal cardiopulmonary exercise test (CPET) in patients with chronic obstructive pulmonary disease (COPD) grouped according to airflow limitation. Methods. Thirty control individuals (control group: CG) and 81 COPD patients (45 with "mild" or "moderate" airflow limitation, COPD_I-II, versus 36 with "severe" or "very severe" COPD, COPD_III-IV) performed a maximal CPET. The first 3 min of recovery kinetics was investigated for oxygen uptake ([Formula: see text]O₂), minute ventilation ([Formula: see text]), respiratory equivalence, and HR. The time for [Formula: see text]O₂ to reach 25% (T_1/4[Formula: see text]O₂) of peak value was also determined and compared. Results. The [Formula: see text]O₂, [Formula: see text], and HR recovery kinetics were significantly slower in both COPD groups than CG (p < 0.05). Moreover, COPD_III-IV group had significantly higher [Formula: see text]O₂ and [Formula: see text] during recovery than COPD_I-II group (p < 0.05). T_1/4[Formula: see text]O₂ significantly differed between groups (p < 0.01; 58 ± 18 s in CG, 79 ± 26 s in COPD_I-II group, and 121 ± 34 s in COPD_III-IV) and was significantly correlated with forced expiratory volume in one second in COPD patients (p < 0.001, r = 0.53) and with peak power output (p < 0.001, r = 0.59). Conclusion. The COPD groups showed slower kinetics in the early recovery period than CG, and the kinetics varied with severity of airflow obstruction.

Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement

This document reviews 1) the measurement properties of commonly used exercise tests in patients with chronic respiratory diseases and 2) published studies on their utilty and/or evaluation obtained from MEDLINE and Cochrane Library searches between 1990 and March 2015.

Exercise tests are reliable and consistently responsive to rehabilitative and pharmacological interventions. Thresholds for clinically important changes in performance are available for several tests. In pulmonary arterial hypertension, the 6-min walk test (6MWT), peak oxygen uptake and ventilation/carbon dioxide output indices appear to be the variables most responsive to vasodilators. While bronchodilators do not always show clinically relevant effects in chronic obstructive pulmonary disease, high-intensity constant work-rate (endurance) tests (CWRET) are considerably more responsive than incremental exercise tests and 6MWTs. High-intensity CWRETs need to be standardised to reduce interindividual variability. Additional physiological information and responsiveness can be obtained from isotime measurements, particularly of inspiratory capacity and dyspnoea. Less evidence is available for the endurance shuttle walk test. Although the incremental shuttle walk test and 6MWT are reliable and less expensive than cardiopulmonary exercise testing, two repetitions are needed at baseline. All exercise tests are safe when recommended precautions are followed, with evidence suggesting that no test is safer than others.

CXCR2 Inhibition Combined with Sorafenib Improved Antitumor and Antiangiogenic Response in Preclinical Models of Ovarian Cancer

Antiangiogenic therapy is important for the treatment of gynecological cancer. However, the therapeutic benefit derived from these treatments is transient, predominantly due to the selective activation of compensatory proangiogenic pathways that lead to rapid development of resistance. We aimed to identify and target potential alternative signaling to anti-vascular endothelial growth factor (VEGF) therapy, with a view toward developing a combination of antiangiogenic agents to provide extended therapeutic benefits. We developed a preclinical in vivo phenotypic resistance model of ovarian cancer resistant to antiangiogenic therapy. We measured dynamic changes in secreted chemokines and angiogenic signaling in tumors and plasma in response to anti-VEGF treatment, as tumors advanced from the initial responsive phase to progressive disease. In tumors that progressed following sorafenib treatment, gene and protein expression levels of proangiogenic CXC chemokines and their receptors were significantly elevated, compared with responsive tumors. The chemokine (C-X-C motif) ligand 8 (CXCL8), also known as interleukin-8 (IL-8) increase was time-dependent and coincided with the dynamics of tumor progression. We used SB225002, a pharmacological inhibitor of chemokine (C-X-C motif) receptor 2 (CXCR2), to disrupt the CXC chemokine-mediated functions of ovarian cancer cells in in vitro assays of cell growth inhibition, spheroid formation, and cell migration. The combination of CXCR2 inhibitor with sorafenib led to a synergistic inhibition of cell growth in vitro, and further stabilized tumor progression following sorafenib in vivo. Our results suggest that CXCR2-mediated chemokines may represent an important compensatory pathway that promotes resistance to antiangiogenic therapy in ovarian cancer. Thus, simultaneous blockage of this proangiogenic cytokine pathway using CXCR2 inhibitors and the VEGF receptor (VEGFR) pathway could improve the outcomes of antiangiogenic therapy.

Heart rate recovery and aerobic endurance capacity in cancer survivors: interdependence and exercise-induced improvements

PURPOSE

Whilst evidence supports beneficial effects of exercise on heart rate variability in cancer patients, its impact on heart rate recovery (HRR) and possible associations of exercise capacity and HRR have not yet been investigated. We aimed to evaluate the effects of an exercise intervention on HRR in relation to the baseline aerobic capacity.

METHODS

Cancer patients (n = 309, 178 females) performed a cardiopulmonary exercise test at baseline and at a 4-month interval follow-up with home-based and supervised exercise programs in-between. VO2 and heart rate were assessed during and HRR at 60 and 120 s after test termination. Based on a median split of the VO2 peak baseline values, participants were dichotomized into two groups: below median (47 female; 57.5 ± 10 years) and above median (48 female; 54.3 ± 12 years).

RESULTS

In the baseline sample (n = 309), VO2 peak correlated significantly with HRR60 (r = .327, p < .01) and HRR120 (r = .524, p < .01). For the compliers who completed intervention and assessments (n = 158), group comparisons demonstrated differences between below median versus above median group in absolute changes of HRR60 (3.1 ± 10.5 bpm (95% CI +0.6; +5.4) vs -1.8 ± 8.7 bpm (95% CI -3.7; +0.5)) and VO2 peak (2.9 ± 3.5 ml/kg/min (95% CI +2.1; +3.7) vs 0.66 ± 4 ml/kg/min (95% CI -0.6; +1.5)) (p < .01), but not in HRR120 (3.9 ± 11.8 bpm (95% CI +1.2; +6.6) vs 0.8 ± 10.8 bpm (95% CI -1.7; +3.5); p > .05).

CONCLUSIONS

These findings point toward a positive linear relationship between aerobic capacity and vagal reactivation in cancer patients. Patients with initial VO2 peak values below median showed improved VO2 peak, HRR60 and HRR120 following the moderate aerobic exercise intervention and differences to patients above median in all outcomes compared.

Resting heart rate: risk indicator and emerging risk factor in cardiovascular disease

Resting heart rate is central to cardiac output and is influenced by changes occurring in numerous diseases. It predicts longevity and cardiovascular diseases, and current evidence suggests that it is also an important marker of outcome in cardiovascular disease, including heart failure. Beta-blockers improve outcomes in heart failure; however, they have effects outside reducing heart rate. Ivabradine has demonstrated efficacy in reducing rehospitalizations and mortality in heart failure and in improving exercise tolerance and reducing angina attacks in patients with coronary artery disease, whereas selective heart rate reduction may also prove to be beneficial in therapeutic areas outside those in which ivabradine has already demonstrated clinical efficacy. This review provides an update on the associations between heart rate and cardiovascular outcomes in various conditions, the experimental effects of heart rate reduction with ivabradine, and the potential new indications in cardiovascular disease.

Effects of interval and continuous exercise training on autonomic cardiac function in COPD patients

BACKGROUND AND AIM

Both interval (IT) and continuous (CT) exercise training results in an improvement of aerobic capacity in patients with chronic obstructive pulmonary disease (COPD); however, their effects on cardiac autonomic function remains unclear. The aim of our study was to evaluate the effect of a supervised CT vs IT on autonomic cardiac function in COPD patients.

METHODS

COPD patients were divided into two different groups according to training modality (IT or CT). Autonomic cardiac dysfunction (ACD) was defined as a heart rate recovery lower than 12 bpm heart rate after the first minute of maximal exercise (HRR1 ) and an abnormal chronotropic response (CR) to exercise (<80%).

RESULTS

A total of 29 patients {mean [standard deviation (SD)] age: 68 (8) years, %FEV1 : 42 (13) predicted} were trained (15 subjects in the CT group, 14 subjects in the IT group). After training, both groups increased peak oxygen consumption [mean difference ΔVO2 peak: 156 mL/min (P = 0.04) on IT; and 210 mL/min (P = 0.01) on CT], HRR1 [IT, from 10.4 (5) to 13.8 (5) bpm (P = 0.04); and CT, from 14.3 (5) to 17.7 (5) bpm (P = 0.04)] and CR [IT, from 57% (22) to 81% (9) (P = 0.001); and CT, from 48% (28) to 73% (17) (P = 0.001)]. Sixteen patients showed ACD. Among these patients, HRR1 (P = 0.01 for IT and P = 0.04 for CT) and CR (P = 0.001 for IT and P = 0.002 for CT) were enhanced after training.

CONCLUSIONS

Both IT and CT exercise training improve heart rate recovery and CR in COPD patients. These benefits could help to individualize exercise training.