Effect of High-Intensity Interval Training on Inhaled Corticosteroid Dose in Asthma Patients: A Randomized Controlled Trial

BACKGROUND

Inhaled corticosteroids (ICS) are the cornerstone of asthma treatment. However, ICS has side effects, and dose reduction is recommended when possible. Physical exercise improves asthma control, but it is unknown whether it reduces the reliance on ICS.

OBJECTIVE

To assess whether supervised high-intensity interval training reduces the need for ICS in untrained asthma patients.

METHODS

An assessor-blinded single-center randomized controlled trial, Copenhagen, Denmark. One hundred fifty untrained ICS-treated adults with symptomatic asthma were randomly assigned (2:1) to 6 months of supervised exercise 3 times weekly or a lifestyle as usual control group. Every second month, a clinical algorithm based on symptom control was applied in both groups to adjust ICS dose. Primary outcome was the proportion who had their ICS dose reduced by 25% or more after 6 months. Secondary outcomes included actual ICS dosage in micrograms per day.

RESULTS

Between October 2017 and December 2019, 102 patients were allocated to exercise intervention (86% completed) and 48 to the control (85% completed). At the 6-month visit, 63% versus 50% met the primary outcome in the exercise and control groups, respectively (adjusted risk difference 9.6% [95% CI -3.8 to 18.8]; P = .15). Daily ICS dose was reduced in favor of the exercise group, with a mean difference of -234 μg (95% CI -391 to -77; P = .0037), corresponding to a 24% reduction from baseline. This effect was sustained at 12 months. The intervention was safe and well tolerated.

CONCLUSIONS

Six months of regular exercise results in reduction in daily ICS dose without compromising asthma control.

High-intensity interval training and health-related quality of life in de novo heart transplant recipients - results from a randomized controlled trial

Background

Studies on the effect of high-intensity interval training (HIT) compared with moderate intensity continuous training (MICT) on health-related quality of life (HRQoL) after heart transplantation (HTx) is scarce. No available studies among de novo HTx recipients exists. This study aimed to investigate the effect of HIT vs. MICT on HRQoL in de novo recipients.

Methods

The HITTS study randomized eighty-one de novo HTx recipients to receive either HIT or MICT (1:1). The HIT intervention were performed with 2–4 interval bouts with an intensity of 85–95% of maximal effort. The MICT group exercised at an intensity of 60–80% of their maximal effort with a duration of 25 min. HRQoL was assessed by the Short Form-36 version 2 (SF-36v2) and the Hospital Anxiety and Depression Scale, mean 11 weeks after surgery and after a nine months’ intervention. The participants recorded their subjective effect of the interventions on their general health and well-being on a numeric visual analogue scale. Clinical examinations and physical tests were performed. Differences between groups were investigated with independent Student t-tests and with Mann-Whitney U tests where appropriate. Within-group differences were analyzed with Paired-Sample t-tests and Wilcoxon Signed Rank tests. Correlations between SF-36 scores and VO_2peak were examined with Pearson’s correlations.

Results

Seventy-eight participants completed the intervention. Both exercise modes were associated with improved exercise capacity on the physical function scores of HRQoL. Mental health scores remained unchanged. No differences in the change in HRQoL between the groups occurred except for Role Emotional subscale with a larger increase in the HIT arm. Better self-reported physical function was associated with higher VO_2peak and muscle strength.

Conclusion

HIT and MICT resulted in similar mean changes in HRQoL the first year after HTx. Both groups experienced significant improvements in the physical SF-36v2.

Trial registration

ClinicalTrials.gov number: NCT01796379 Registered 18 February 2013.

Clinical features and determinants of VO2peak in de novo heart transplant recipients

AIM

To study exercise capacity and determinants of early peak oxygen consumption (VO_2peak) in a cohort of de novo heart transplant (HTx) recipients.

METHODS

To determine possible central (chronotropic responses, cardiopulmonary and hemodynamic function) and peripheral factors (muscular exercise capacity and body composition) predictive of VO_2peak, a number of different measurements and tests were performed, as follows: Cardiopulmonary exercise testing (CPET) was performed mean 11 wk after surgery in 81 HTx recipients > 18 years and was measured with breath by breath gas exchange on a treadmill or bicycle ergometer. Metabolic/respiratory measures include VO_2peak and VE/VCO₂ slope. Additional measures included muscle strength testing, bioelectrical impedance analysis, echocardiography, blood sampling and health-related quality of life. Based on the VO_2peak (mL/kg per minute) median value, the study population was divided into two groups defined as a low-capacity group and a high-capacity group. Potential predictors were analyzed using multiple regression analysis with VO_2peak (L/min) as the dependent variable.

RESULTS

The mean ± standard deviation (SD) age of the total study population was 49 ± 13 years, and 73% were men. This de novo HTx cohort demonstrated a median VO_2peak level of 19.4 mL/kg per min at 11 ± 1.8 wk post-HTx. As compared with the high-capacity group, the low-capacity group exercised for a shorter time, had lower maximal ventilation, O₂ pulse, peak heart rate and heart rate reserve, while the VE/VCO₂ slope was higher. The low-capacity group had less muscle strength and muscular exercise capacity in comparison with the high-capacity group. In order of importance, O₂ pulse, heart rate reserve, muscular exercise capacity, body mass index, gender and age accounted for 84% of the variance in VO_2peak (L/min). There were no minor or major serious adverse events during the CPET.

CONCLUSION

Although there is great individual variance among de novo HTx recipients, early VO_2peak measures appear to be influenced by both central and peripheral factors.

Exercise-based cardiac rehabilitation in heart transplant recipients

BACKGROUND

Heart transplantation is considered to be the gold standard treatment for selected patients with end-stage heart disease when medical therapy has been unable to halt progression of the underlying pathology. Evidence suggests that aerobic exercise training may be effective in reversing the pathophysiological consequences associated with cardiac denervation and prevent immunosuppression-induced adverse effects in heart transplant recipients.

OBJECTIVES

To determine the effectiveness and safety of exercise-based rehabilitation on the mortality, hospital admissions, adverse events, exercise capacity, health-related quality of life, return to work and costs for people after heart transplantation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO) and Web of Science Core Collection (Thomson Reuters) to June 2016. We also searched two clinical trials registers and handsearched the reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of parallel group, cross-over or cluster design, which compared exercise-based interventions with (i) no exercise control (ii) a different dose of exercise training (e.g. low- versus high-intensity exercise training); or (iii) an active intervention (i.e. education, psychological intervention). The study population comprised adults aged 18 years or over who had received a heart transplant.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references for inclusion based on pre-specified inclusion criteria. Disagreements were resolved by consensus or by involving a third person. Two review authors extracted outcome data from the included trials and assessed their risk of bias. One review author extracted study characteristics from included studies and a second author checked them against the trial report for accuracy.

MAIN RESULTS

We included 10 RCTs that involved a total of 300 participants whose mean age was 54.4 years. Women accounted for fewer than 25% of all study participants. Nine trials which randomised 284 participants to receive exercise-based rehabilitation (151 participants) or no exercise (133 participants) were included in the main analysis. One cross-over RCT compared high-intensity interval training with continued moderate-intensity training in 16 participants. We reported findings for all trials at their longest follow-up (median 12 weeks).Exercise-based cardiac rehabilitation increased exercise capacity (VO_2peak) compared with no exercise control (MD 2.49 mL/kg/min, 95% CI 1.63 to 3.36; N = 284; studies = 9; moderate quality evidence). There was evidence from one trial that high-intensity interval exercise training was more effective in improving exercise capacity than continuous moderate-intensity exercise (MD 2.30 mL/kg/min, 95% CI 0.59 to 4.01; N = 16; 1 study). Four studies reported health-related quality of life (HRQoL) measured using SF-36, Profile of Quality of Life in the Chronically Ill (PLC) and the World Health Organization Quality Of Life (WHOQoL) - BREF. Due to the variation in HRQoL outcomes and methods of reporting we were unable to meta-analyse results across studies, but there was no evidence of a difference between exercise-based cardiac rehabilitation and control in 18 of 21 HRQoL domains reported, or between high and moderate intensity exercise in any of the 10 HRQoL domains reported. One adverse event was reported by one study.Exercise-based cardiac rehabilitation improves exercise capacity, but exercise was found to have no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients whose health is stable.There was no evidence of statistical heterogeneity across trials for exercise capacity and no evidence of small study bias. The overall risk of bias in included studies was judged as low or unclear; more than 50% of included studies were assessed at unclear risk of bias with respect to allocation concealment, blinding of outcome assessors and declaration of conflicts of interest. Evidence quality was assessed as moderate according to GRADE criteria.

AUTHORS' CONCLUSIONS

We found moderate quality evidence suggesting that exercise-based cardiac rehabilitation improves exercise capacity, and that exercise has no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients. Cardiac rehabilitation appears to be safe in this population, but long-term follow-up data are incomplete and further good quality and adequately-powered trials are needed to demonstrate the longer-term benefits of exercise on safety and impact on both clinical and patient-related outcomes, such as health-related quality of life, and healthcare costs.

Exercise-based cardiac rehabilitation in heart transplant recipients

BACKGROUND

Heart transplantation is considered to be the gold standard treatment for selected patients with end-stage heart disease when medical therapy has been unable to halt progression of the underlying pathology. Evidence suggests that aerobic exercise training may be effective in reversing the pathophysiological consequences associated with cardiac denervation and prevent immunosuppression-induced adverse effects in heart transplant recipients.

OBJECTIVES

To determine the effectiveness and safety of exercise-based rehabilitation on the mortality, hospital admissions, adverse events, exercise capacity, health-related quality of life, return to work and costs for people after heart transplantation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO) and Web of Science Core Collection (Thomson Reuters) to June 2016. We also searched two clinical trials registers and handsearched the reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of parallel group, cross-over or cluster design, which compared exercise-based interventions with (i) no exercise control (ii) a different dose of exercise training (e.g. low- versus high-intensity exercise training); or (iii) an active intervention (i.e. education, psychological intervention). The study population comprised adults aged 18 years or over who had received a heart transplant.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references for inclusion based on pre-specified inclusion criteria. Disagreements were resolved by consensus or by involving a third person. Two review authors extracted outcome data from the included trials and assessed their risk of bias. One review author extracted study characteristics from included studies and a second author checked them against the trial report for accuracy.

MAIN RESULTS

We included 10 RCTs that involved a total of 300 participants whose mean age was 54.4 years. Women accounted for fewer than 25% of all study participants. Nine trials which randomised 284 participants to receive exercise-based rehabilitation (151 participants) or no exercise (133 participants) were included in the main analysis. One cross-over RCT compared high-intensity interval training with continued moderate-intensity training in 16 participants. We reported findings for all trials at their longest follow-up (median 12 weeks).Exercise-based cardiac rehabilitation increased exercise capacity (VO2peak) compared with no exercise control (MD 2.49 mL/kg/min, 95% CI 1.63 to 3.36; N = 284; studies = 9; moderate quality evidence). There was evidence from one trial that high-intensity interval exercise training was more effective in improving exercise capacity than continuous moderate-intensity exercise (MD 2.30 mL/kg/min, 95% CI 0.59 to 4.01; N = 16; 1 study). Four studies reported health-related quality of life (HRQoL) measured using SF-36, Profile of Quality of Life in the Chronically Ill (PLC) and the World Health Organization Quality Of Life (WHOQoL) - BREF. Due to the variation in HRQoL outcomes and methods of reporting we were unable to meta-analyse results across studies, but there was no evidence of a difference between exercise-based cardiac rehabilitation and control in 18 of 21 HRQoL domains reported, or between high and moderate intensity exercise in any of the 10 HRQoL domains reported. One adverse event was reported by one study.Exercise-based cardiac rehabilitation improves exercise capacity, but exercise was found to have no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients whose health is stable.There was no evidence of statistical heterogeneity across trials for exercise capacity and no evidence of small study bias. The overall risk of bias in included studies was judged as low or unclear; more than 50% of included studies were assessed at unclear risk of bias with respect to allocation concealment, blinding of outcome assessors and declaration of conflicts of interest. Evidence quality was assessed as moderate according to GRADE criteria.

AUTHORS' CONCLUSIONS

We found moderate quality evidence suggesting that exercise-based cardiac rehabilitation improves exercise capacity, and that exercise has no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients. Cardiac rehabilitation appears to be safe in this population, but long-term follow-up data are incomplete and further good quality and adequately-powered trials are needed to demonstrate the longer-term benefits of exercise on safety and impact on both clinical and patient-related outcomes, such as health-related quality of life, and healthcare costs.

Effect of moderate- versus high-intensity exercise on vascular function, biomarkers and quality of life in heart transplant recipients: A randomized, crossover trial

BACKGROUND

Growing evidence in long-term treatment of heart transplant (HTx) recipients indicates effects of high-intensity interval training (HIIT) on several parameters, including oxygen uptake, vascular function and psychological distress. In this study we compare the effect of HIIT vs continued moderate training (CON) on vascular function, biomarkers and health-related quality of life (HRQoL) in HTx recipients.

METHODS

A randomized, controlled crossover trial of stable HTx recipients >12 months after transplantation was done on patients with 12 weeks of HIIT or 12 weeks of CON, followed by a 5-month washout and crossover. Outcomes included endothelial function, arterial stiffness, biomarkers, HRQoL and markers of anxiety and depression.

RESULTS

Sixteen HTx recipients (mean age 52 years, 75% male) completed the study. HIIT increased VO(2peak) more than CON (between-group difference, p < 0.001). The physical component score of the 36-item Short Form (SF-36) was increased significantly in HIIT patients (p = 0.02) and borderline increased in CON patients (p = 0.07), whereas there was no significant effect of exercise on the mental component. Depression score decreased significantly in HIIT patients (p = 0.04) with no change in CON patients (p = 0.75), whereas anxiety score decreased significantly in both HIIT (p < 0.01) and CON (p < 0.05) patients. There were no between-group differences in any of the measures (all p > 0.05). Arterial stiffness and biomarkers were not changed, nor did endothelial function change after HIIT (p = 0.08) or CON (p = 0.68).

CONCLUSIONS

HIIT and CON are both well tolerated and induce similar improvements in physical components of HRQoL and in markers of anxiety. Effects of either training modality on vascular function and biomarkers could not be confirmed.

Effect of high-intensity training versus moderate training on peak oxygen uptake and chronotropic response in heart transplant recipients: a randomized crossover trial

In heart transplant (HTx) recipients, there has been reluctance to recommend high-intensity interval training (HIIT) due to denervation and chronotropic impairment of the heart. We compared the effects of 12 weeks' HIIT versus continued moderate exercise (CON) on exercise capacity and chronotropic response in stable HTx recipients >12 months after transplantation in a randomized crossover trial. The study was completed by 16 HTx recipients (mean age 52 years, 75% males). Baseline peak oxygen uptake (VO2peak ) was 22.9 mL/kg/min. HIIT increased VO2peak by 4.9 ± 2.7 mL/min/kg (17%) and CON by 2.6 ± 2.2 mL/kg/min (10%) (significantly higher in HIIT; p < 0.001). During HIIT, systolic blood pressure decreased significantly (p = 0.037) with no significant change in CON (p = 0.241; between group difference p = 0.027). Peak heart rate (HRpeak ) increased significantly by 4.3 beats per minute (p = 0.014) after HIIT with no significant change in CON (p = 0.34; between group difference p = 0.027). Heart rate recovery (HRrecovery ) improved in both groups with a trend toward greater improvement after HIIT. The 5-month washout showed a significant loss of improvement. HIIT was well tolerated, had a superior effect on oxygen uptake, and led to an unexpected increase in HRpeak accompanied by a faster HRrecovery . This indicates that the benefits of HIIT are partly a result of improved chronotropic response.

Interval training does not modulate diastolic function in heart transplant recipients

OBJECTIVES

This study investigates the effect of aerobic interval training on diastolic function at rest and during exercise in stable heart transplant (HTx) recipients.

DESIGN

Twenty-three stable HTx recipients (74% males, mean age 50 ± 14.9 years) were recruited to a training programme. Intervention was 8 weeks intensive training or control in a randomized controlled design.

RESULTS

At baseline, participants had normal or mild diastolic dysfunction at rest. During exercise, mean E/e' increased from 9.0 (± 2.8) to 12.8 (± 7.7) (p = 0.09), E/A increased from 2.1 (± 0.6) to 2.6 (± 0.7) (p = 0.02), and deceleration time decreased by over 50 ms, all markers of increased filling pressure. There were no correlations between diastolic function and VO 2 peak at baseline. After intervention VO 2 peak increased from 23.9 (± 4.5) to 28.3(± 6) ml/kg/min in the training group (difference between groups p = 0.0018). No consistent pattern of improvement in diastolic function at rest or during exercise was seen.

CONCLUSION

The study does not support a role of diastolic dysfunction in the limited exercise capacity of HTx recipients and suggests that in these patients peripheral factors are of greater importance.

Effect of high intensity exercise on peak oxygen uptake and endothelial function in long-term heart transplant recipients

Coronary allograft vasculopathy is a well-known long-term complication after cardiac transplantation. Endothelial dysfunction is involved and may be prevented by aerobic exercise. The purpose of this study was to examine whether high intensity aerobic exercise improves peak oxygen uptake (VO(2 peak) ) and endothelial function in heart transplant (HT) recipients. Twenty-seven long-term HT recipients were randomized to either 8-weeks high intensity aerobic exercise or no training. Flow mediated dilation of the brachial artery (FMD) was measured by ultrasound and VO(2 peak) by the analysis of expired air. Blood pressure and biomarkers were measured before and after 8 weeks. VO(2 peak) increased significantly in the exercise group (VO(2 peak) 23.9 ± 1.79 to 28.3 ± 1.63 mL/kg/min compared to controls (VO(2 peak) 24.6 ± 1.38 to 23.4 ± 1.58, p < 0.001 exercise vs. control).FMD increased in the exercise group compared to controls (8.3 ± 1.1% to 11.4 ± 1.2% vs. 5.6 ± 1.0% to 5.3 ± 1.7%, p = 0.024). No increase in nitroglycerin-induced vasodilation was observed. Systolic blood pressure fell in the exercise group (142 ±4.2 mmHg to127 ± 3.4 mmHg, p = 0.01) and was unchanged in controls (141 ± 4.2 mmHg to 142 ±6.4 mmHg, NS). High intensity aerobic exercise reduces systolic blood pressure and improves endothelial function in HT recipients.