Acute exercise is associated with reduced exhaled nitric oxide in physically inactive adults with asthma

Exercise Recommendations and Practical Considerations for Asthma Management-An EAACI Position Paper

Exercise is an important treatment for people with asthma and should be considered alongside pharmacological therapy when developing personalised asthma management plans. Despite this, there remains limited guidance concerning the practicalities of asthma-specific exercise prescription. This European Academy of Allergy and Clinical Immunology task force was therefore established to achieve three fundamental aims: first, to provide an up-to-date perspective concerning the role of exercise for asthma management (i.e., describe the disease modifying potential of exercise and associated impact on asthma-related extrapulmonary comorbidities); second, to develop pragmatic recommendations to facilitate safe and effective exercise prescription; and third, to identify key unmet needs and provide focused direction for future research. The position paper is structured as a practically focused document, with recommendations formulated according to best available scientific evidence and expert opinion, with an emphasis on providing healthcare providers with pragmatic advice that can be implemented during routine asthma review.

Acute supplementation with a curcuminoid-based formulation fails to enhance resting or exercise-induced NRF2 activity in males and females

Purpose: Exercise and (poly)phenols may activate nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor that coordinates antioxidant synthesis. The purpose of this study was to determine whether curcuminoid supplementation augments resting and exercise-induced NRF2 activity. Methods: In a double-blinded, randomised, between-subjects design, 14 males and 12 females performed plyometric exercise (100 drop jumps, 50 squat jumps) following 4 d supplementation with a curcuminoid-based formulation (CUR + EX; n = 13; ∼200 mg d-1 curcuminoids) or a placebo (PLA + EX; n = 13). NRF2/DNA binding in peripheral blood mononuclear cells, plasma glutathione peroxidase (GPX), and plasma cytokines (interleukin-6 [IL-6], tumour necrosis factor-alpha [TNF-α]) were measured pre-, post-, 1, 2 h post-exercise. Curcuminoid metabolites were measured 0, 1, 2 h post-administration of a single bolus. Results: Total area under the curve for total curcuminoid metabolites was greater in CUR + EX (p < 0.01), with bioavailability peaking at 2 h post administration (CUR + EX: [0 h] 80.9 ± 117 nM [1 h] 76.6 ± 178.5 nM [2 h] 301.1 ± 584.7 nM; PLA + EX: [0 h] 10.4 ± 1.6 [1 h] 8.5 ± 2.6 [2 h] 10.6 ± 2.1). NRF2 activity did not increase in PLA + EX (p = 0.78) or CUR + EX (p = 0.76); however, curcuminoid metabolite concentrations did positively predict NRF2/DNA binding (R2 = 0.39; p = 0.02). Exercise increased IL-6 (p = 0.03) but TNF-α was unresponsive (p = 0.97) and lower across PLA + EX (p = 0.03). GPX activity was higher in CUR + EX (p < 0.01) but not in PLA + EX (p = 0.94). Conclusion: Supplementation with a curcuminoid-based formulation failed to augment resting or exercise-induced NRF2/DNA binding; however, higher concentrations of curcuminoid metabolites predicted NRF2/DNA binding response, suggesting effects may be dependent on bioavailability.

Effects of Moderate- Versus Vigorous-Intensity Exercise Training on Asthma Outcomes in Adults

BACKGROUND

The therapeutic effects of exercise have prompted calls for it to be embedded into standard asthma care, but evidence informing the optimal exercise intensity is lacking.

OBJECTIVE

This study aimed to compare the effects of moderate- and vigorous-intensity aerobic exercise training on asthma outcomes and inflammation.

METHODS

This was a 12-week randomized controlled trial in 46 adults with asthma randomized to either (1) 45-minute moderate-intensity exercise training 3 times/wk, (2) 30-minute vigorous-intensity exercise training 3 times/wk, or (3) the control group. Asthma-related quality of life (AQLQ), asthma control (ACQ), cardiorespiratory fitness, body composition, and airway and systemic inflammation were assessed before and after the intervention.

RESULTS

Forty-one participants completed the study (89% retention). The moderate-intensity group had a statistically and clinically significant improvement in AQLQ (0.63 [0.33-0.93], P < .001) and ACQ (-0.51 [-0.83 to -0.19], P = .003) relative to control. The vigorous-intensity group had a statistically, but not clinically, significant improvement in AQLQ (0.46 [0.14-0.80], P = .007) and ACQ (-0.36 [-0.69 to -0.02], P = .040) relative to control. After moderate-intensity training, there was a reduction in sputum macrophage (-1341 [-2491 to -191] × 104/mL, P = .024) and lymphocyte (-114 [-220 to -8] × 104/mL, P = .036) counts relative to control. A reduction in android fat mass, but not a change in fitness, was associated with improved AQLQ (rs = -0.341, P = .030) and reduced sputum IL-6 (rs = 0.422, P = .013).

CONCLUSIONS

Our findings suggest that both moderate-intensity and vigorous-intensity aerobic exercise training are associated with improvements in clinical asthma outcomes and, therefore, both intensities could be recommended as an adjuvant asthma therapy.

The Effect of Varying Fatty Acid Composition on Postprandial Airway Inflammation, Pulmonary Function, and Airway Resistance in Healthy, Young Adults

OBJECTIVE

To examine the effect of varying fatty acid composition in a HFM on eNO, pulmonary function, and airway resistance.

METHODS

Fifteen individuals [6 M/9 F; 21.9 ± 1.5 years old] each completed three HFM conditions {SF, O6FA, and O3FA; 12 kcal/kg body weight, 63% total fat, and 0.72 g/kg sugar smoothies} in random order separated by at least 48 h. Airway inflammation assessed via eNO, pulmonary function measured using the maximum flow volume loop (MFVL) and airway resistance measured using impulse oscillometry (iOS) were taken at baseline, 2h and 4h postprandially.

RESULTS

There was no difference in eNO or iOS across time in any condition or between conditions (p > 0.05). There was a significant time by condition effect for FEV1 post-HFM in the SF and O6FA conditions (p < 0.05).

CONCLUSION

Different fatty acid compositions do not increase eNO or iOS in healthy, college-aged participants after consumption of a HFM, though the minimally processed meals with fruit added may contribute to these findings.

Combined effects of green tea supplementation and eccentric exercise on nuclear factor erythroid 2-related factor 2 activity

PURPOSE

This study investigated whether combining eccentric exercise and green tea supplementation synergistically increased nuclear factor erythroid 2-related factor 2 (NRF2) activity, a transcription factor responsible for coordinating endogenous antioxidant expression.

METHODS

In a double-blinded, randomized, between-subjects design, 24 males (mean [SD]; 23 [3] years, 179.6 [6.1] cm, 78.8 [10.6] kg) performed 100 drop jumps following a 6 days supplementation period with either green tea (poly)phenols (n = 12; 500 mg·d-1) or a placebo (n = 12; inulin). NRF2/antioxidant response element (ARE) binding in peripheral blood mononuclear cells (PBMCs), catalase (CAT) and glutathione reductase (GR) activity, 8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion, and differential leukocyte counts were measured pre-, post-, 1 h and 24 h post-exercise.

RESULTS

Exercise did not increase NRF2/ARE binding (p = 0.12) (fold change vs rest: green tea = [post] 0.78 ± 0.45, [1 h] 1.17 ± 0.54, [24 h] 1.06 ± 0.56; placebo = [post] 1.40 ± 1.50, [1 h] 2.98 ± 3.70, [24 h] 1.04 ± 0.45). Furthermore, CAT activity (p = 0.12) and 8-OHdG excretion (p = 0.42) were unchanged in response to exercise and were not augmented by green tea supplementation (p > 0.05 for all). Exercise increased GR activity by 30% (p = 0.01), however no differences were found between supplement groups (p = 0.51). Leukocyte and neutrophil concentrations were only elevated post-exercise (p < 0.001 for all).

CONCLUSION

Eccentric exercise, either performed alone or in conjunction with green tea supplementation, did not significantly increase NRF2 activity in PBMCs.

TRIAL REGISTRATION NUMBER

osf.io/kz37g (registered: 15/09/21).

Mechanically demanding eccentric exercise increases nuclear factor erythroid 2-related factor 2 activity in human peripheral blood mononuclear cells

PRE-REGISTRATION NUMBER

osf.io/kz37g.

Effects of physical activity on lung function and quality of life in asthmatic children: An updated systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The benefits of physical activity (PA) for asthmatic children were increasingly recognized, and as the design of studies on PA and asthma has become more refined in recent years, the latest evidence needed to be updated. We performed this meta-analysis to synthesize the evidence available from the last 10 years to update the effects of PA in asthmatic children.

METHODS

A systematic search was conducted in three databases, PubMed, Web of Science, and Cochrane Library. Randomized controlled trials were included, and two reviewers independently conducted the inclusion screening, data extraction, and bias assessment.

RESULTS

A total of 9 studies were included in this review after 3,919 articles screened. PA significantly improved the forced vital capacity (FVC) (MD 7.62; 95% CI: 3.46 to 11.78; p < 0.001), and forced expiratory flow between 25% and 75% of forced vital capacity (FEF_25-75) (MD 10.39; 95% CI: 2.96 to 17.82; p = 0.006) in lung function. There was no significant difference in forced expiratory volume in the first second (FEV₁) (MD 3.17; 95% CI: -2.82 to 9.15; p = 0.30) and fractional exhaled nitric oxide (FeNO) (MD -1.74; 95% CI: -11.36 to 7.88; p = 0.72). Also, PA significantly improved the quality of life as assessed by the Pediatric Asthma Quality of Life Questionnaire (all items p < 0.05).

CONCLUSIONS

This review suggested that PA could improve FVC, FEF_25-75, and quality of life in asthmatic children, but there was insufficient evidence of improvement in FEV₁ and airway inflammation.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022338984.

Physical training in adults with asthma: An integrative approach on strategies, mechanisms, and benefits

Asthma is a chronic airway disease characterized by airflow limitation and respiratory symptoms associated with chronic airway and systemic inflammation, bronchial hyperreactivity (BHR), and exercise-induced bronchoconstriction (EIB). Asthma is a heterogeneous disease classified according to distinct airway and systemic inflammation. Patients commonly present with several comorbidities, including anxiety, depression, poor sleep quality, and reduced physical activity levels. Individuals with moderate to severe asthma often have more symptoms and difficulty achieving adequate clinical control, which is associated with poor quality of life, despite proper pharmacological treatment. Physical training has been proposed as an adjunctive therapy for asthma. Initially, it was suggested that the effect of physical training might be attributed to the improved oxidative capacity and reduced production of exercise metabolites. However, in the last decade, there has been evidence that aerobic physical training promotes anti-inflammatory effects in asthma patients. Physical training improves BHR and EIB, asthma symptoms, clinical control, anxiety, and depression levels, sleep quality, lung function, exercise capacity, and dyspnea perception. Furthermore, physical training reduces medication consumption. The most commonly used exercise strategies are moderate aerobic and breathing exercises; however, other techniques, such as high-intensity interval training, have shown promising effects. In the present study, we reviewed the strategies and beneficial effects of exercise on clinical and pathophysiological asthma outcomes.

Physical activity, physical capacity and sedentary behavior among asthma patients

BACKGROUND: Although exercise and daily physical activity (PA) have long been known to benefit patients with chronic disorders, knowledge is limited regarding asthma.

OBJECTIVE: In a Danish setting, our aim was to measure physical activity, sedentary behavior, and physical capacity among patients with asthma. We hypothesized that people with severe asthma would be less active and more sedentary than their mild-moderate counterparts.

METHODS: Adults with asthma were recruited through respiratory outpatient clinics and subsequently examined twice, 4 weeks apart. At each visit, participants underwent a series of lung function tests, questionnaires, and maximum oxygen uptake testing (VO₂max). Between the visits, participants wore an accelerometer continuously for 4 weeks, measuring sedentary time and daily steps. Sixty patients, 27 with mild-moderate asthma (GINA 1–3) and 33 with severe asthma (GINA 4–5), completed both visits and had valid accelerometer measurements.

RESULTS: No significant differences between the two groups were found in sedentary time, number of steps or VO₂max.   VO₂max was significantly correlated with FeNO (r = −0.30, p < 0.05), Short Form-12 Mental Health (r = 0.37, p < 0.05), Asthma Control Questionnaire (r = −0.35, p < 0.05), and Mini Asthma Quality of Life Questionnaire (r = 0.36, p < 0.05).

CONCLUSION: No differences were observed between patients with mild-moderate and severe asthma regarding sedentary behavior, daily steps or level of cardiopulmonary fitness. Furthermore, patients with the highest VO₂max had the higher quality of life scores.

Abbreviations: VO₂max: Maximal Oxygen Uptake; CPET: Cardiopulmonary Exercise Testing; BMI: Body Mass Index; FEV1: Forced Expired Volume in the First Second; FVC: Forced Vital Capacity; PEF: Peak Expiratory Flow; EIB: Exercise-Induced Bronchoconstriction; COPD: Chronic Obstructive Pulmonary Disease; ACQ: Asthma Control Questionnaire; Mini-AQLQ: Mini Asthma Quality of Life Questionnaire; SF-12: Short Form 12 Health Survey; SNOT-22: Sino-Nasal Outcome Test 22; GINA: The Global Initiative for Asthma; CRP: C-reactive Protein; Hgb:Hemoglobin count; EOS: Eosinophil count; EVH: Eucapnic Voluntary Hyperventilation; FeNO: Fractional Exhaled Nitric Oxide; PA: Physical Activity ERS: European Respiratory Society; ATS: American Thoracic Society; CRS: Chronic Rhinosinusitis; AHR: Airway Hyperresponsiveness

Comparing the Effect of Acute Moderate and Vigorous Exercise on Inflammation in Adults with Asthma: A Randomized Controlled Trial

Rationale: Exercise is associated with improvements in asthma; however, the mechanisms responsible are not clear. Exercise induces changes in systemic inflammation, and it is possible that these inflammatory effects extend to the airways of people with asthma. Studies in healthy adults suggest inflammatory responses are dependent on exercise intensity: Although acute moderate exercise is antiinflammatory, acute vigorous exercise appears to be neutral or proinflammatory. The effect of exercise intensity on inflammation has not been investigated in people with asthma. Objectives: To compare acute changes in airway and systemic inflammation after a bout of moderate or vigorous exercise in physically inactive adults with asthma and to establish whether these effects differ according to asthma phenotype. Methods: Participants were randomized to either 1) control (no intervention), 2) 45 minutes of moderate exercise, or 3) 30 minutes of vigorous exercise. Induced sputum and blood samples were collected at baseline and 4 hours after intervention. Results: Fifty-six participants (75% female; mean age, 33.4 [9.9] yr) completed the trial. Moderate exercise induced a significant reduction in sputum eosinophil count (-173 [-337 to -10]; P = 0.032) and sputum percentage eosinophils (-2.2 [-4.9 to 0.5]; P = 0.049) relative to control. Vigorous exercise had no effect on airway inflammation. The antiinflammatory effects of moderate exercise were greatest in participants with eosinophilic asthma, with larger reductions in sputum eosinophils and larger increases in plasma interleukin (IL)-1ra than seen in participants with noneosinophilic asthma. Vigorous exercise induced a systemic proinflammatory response in participants with eosinophilic asthma, indicated by an increase in serum IL-5 and IL-1β; however, this had no effect on airway inflammation. Conclusions: Exercise intensity modifies the acute inflammatory response to exercise in adults with asthma. Although a bout of moderate exercise is associated with a reduction in eosinophilic airway inflammation, vigorous exercise has no effect on airway inflammation. Interestingly, the effects of moderate exercise vary by asthma phenotype, with greater antiinflammatory effects in participants with eosinophilic asthma. Future studies should examine the impact of exercise training at different intensities on inflammation and clinical asthma outcomes. Clinical trial registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12615000294550).

Acute Exercise and the Systemic and Airway Inflammatory Response to a High-Fat Meal in Young and Older Adults

The purpose of the present study was to determine fasting and high-fat meal (HFM)-induced post-prandial systemic inflammation and airway inflammation (exhaled nitric oxide (eNO)) in older adults (OAs) compared to younger adults (YAs) before and after acute exercise. Twelve YAs (23.3 ± 3.9 y n = 5 M/7 F) and 12 OAs (67.7 ± 6 y, n = 8 M/4 F) completed two HFM challenges. After an overnight fast, participants underwent an HFM session or pre-prandial exercise (EX, 65% VO2Peak to expend 75% of the caloric content of the HFM) plus HFM (EX + HFM) in a randomized order. Systemic inflammatory cytokines were collected at 0, 3, and 6 h, while eNO was determined at 0, 2, and 4 h after the HFM (12 kcal/kg body weight: 61% fat, 35% CHO, 4% PRO). TNF-α was higher in OAs compared to YAs (p = 0.005) and decreased across time from baseline to 6 h post-HFM (p = 0.007). In response to the HFM, IL-6 decreased from 0 to 3 h but increased at 6 h regardless of age or exercise (p = 0.018). IL-8 or IL-1β did not change over the HFM by age or exercise (p > 0.05). eNO was also elevated in OAs compared to YAs (p = 0.003) but was not altered by exercise (p = 0.108). There was a trend, however, towards significance post-prandially in OAs and YAs from 0 to 2 h (p = 0.072). TNF-α and eNO are higher in OAs compared to YAs but are not elevated more in OAs post-prandially compared to YAs. Primary systemic inflammatory cytokines and eNO were not modified by acute exercise prior to an HFM.

Pulmonary rehabilitation versus usual care for adults with asthma

BACKGROUND

Asthma is a respiratory disease characterised by variable airflow limitation and the presence of respiratory symptoms including wheeze, chest tightness, cough and/or dyspnoea. Exercise training is beneficial for people with asthma; however, the response to conventional models of pulmonary rehabilitation is less clear.

OBJECTIVES

To evaluate, in adults with asthma, the effectiveness of pulmonary rehabilitation compared to usual care on exercise performance, asthma control, and quality of life (co-primary outcomes), incidence of severe asthma exacerbations/hospitalisations, mental health, muscle strength, physical activity levels, inflammatory biomarkers, and adverse events.

SEARCH METHODS

We identified studies from the Cochrane Airways Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform, from their inception to May 2021, as well as the reference lists of all primary studies and review articles.

SELECTION CRITERIA

We included randomised controlled trials in which pulmonary rehabilitation was compared to usual care in adults with asthma. Pulmonary rehabilitation must have included a minimum of four weeks (or eight sessions) aerobic training and education or self-management. Co-interventions were permitted; however, exercise training alone was not.  DATA COLLECTION AND ANALYSIS: Following the use of Cochrane's Screen4Me workflow, two review authors independently screened and selected trials for inclusion, extracted study characteristics and outcome data, and assessed risk of bias using the Cochrane risk of bias tool. We contacted study authors to retrieve missing data. We calculated between-group effects via mean differences (MD) or standardised mean differences (SMD) using a random-effects model. We evaluated the certainty of evidence using GRADE methodology.

MAIN RESULTS

We included 10 studies involving 894 participants (range 24 to 412 participants (n = 2 studies involving n > 100, one contributing to meta-analysis), mean age range 27 to 54 years). We identified one ongoing study and three studies awaiting classification. One study was synthesised narratively, and another involved participants specifically with asthma-COPD overlap. Most programmes were outpatient-based, lasting from three to four weeks (inpatient) or eight to 12 weeks (outpatient). Education or self-management components included breathing retraining and relaxation, nutritional advice and psychological counselling. One programme was specifically tailored for people with severe asthma.  Pulmonary rehabilitation compared to usual care may increase maximal oxygen uptake (VO2 max) after programme completion, but the evidence is very uncertain for data derived using mL/kg/min (MD between groups of 3.63 mL/kg/min, 95% confidence interval (CI) 1.48 to 5.77; 3 studies; n = 129) and uncertain for data derived from % predicted VO2 max (MD 14.88%, 95% CI 9.66 to 20.1%; 2 studies; n = 60). The evidence is very uncertain about the effects of pulmonary rehabilitation compared to usual care on incremental shuttle walk test distance (MD between groups 74.0 metres, 95% CI 26.4 to 121.4; 1 study; n = 30). Pulmonary rehabilitation may have little to no effect on VO2 max at longer-term follow up (9 to 12 months), but the evidence is very uncertain (MD -0.69 mL/kg/min, 95% CI -4.79 to 3.42; I2 = 49%; 3 studies; n = 66). Pulmonary rehabilitation likely improves functional exercise capacity as measured by 6-minute walk distance, with MD between groups after programme completion of 79.8 metres (95% CI 66.5 to 93.1; 5 studies; n = 529; moderate certainty evidence). This magnitude of mean change exceeds the minimally clinically important difference (MCID) threshold for people with chronic respiratory disease. The evidence is very uncertain about the longer-term effects one year after pulmonary rehabilitation for this outcome (MD 52.29 metres, 95% CI 0.7 to 103.88; 2 studies; n = 42). Pulmonary rehabilitation may result in a small improvement in asthma control compared to usual care as measured by Asthma Control Questionnaire (ACQ), with an MD between groups of -0.46 (95% CI -0.76 to -0.17; 2 studies; n = 93; low certainty evidence); however, data derived from the Asthma Control Test were very uncertain (MD between groups 3.34, 95% CI -2.32 to 9.01; 2 studies; n = 442). The ACQ finding approximates the MCID of 0.5 points. Pulmonary rehabilitation results in little to no difference in asthma control as measured by ACQ at nine to 12 months follow-up (MD 0.09, 95% CI -0.35 to 0.53; 2 studies; n = 48; low certainty evidence). Pulmonary rehabilitation likely results in a large improvement in quality of life as assessed by the St George's Respiratory Questionnaire (SGRQ) total score (MD -18.51, 95% CI -20.77 to -16.25; 2 studies; n = 440; moderate certainty evidence), with this magnitude of change exceeding the MCID. However, pulmonary rehabilitation may have little to no effect on Asthma Quality of Life Questionnaire (AQLQ) total scores, with the evidence being very uncertain (MD 0.87, 95% CI -0.13 to 1.86; 2 studies; n = 442). Longer-term follow-up data suggested improvements in quality of life may occur as measured by SGRQ (MD -13.4, 95% CI -15.93 to -10.88; 2 studies; n = 430) but not AQLQ (MD 0.58, 95% CI -0.23 to 1.38; 2 studies; n = 435); however, the evidence is very uncertain. One study reported no difference between groups in the proportion of participants who experienced an asthma exacerbation during the intervention period. Data from one study suggest adverse events attributable to the intervention are rare.  Overall risk of bias was most commonly impacted by performance bias attributed to a lack of participant blinding to knowledge of the intervention. This is inherently challenging to overcome in rehabilitation studies.  AUTHORS' CONCLUSIONS: Moderate certainty evidence shows that pulmonary rehabilitation is probably associated with clinically meaningful improvements in functional exercise capacity and quality of life upon programme completion in adults with asthma. The certainty of evidence relating to maximal exercise capacity was very low to low. Pulmonary rehabilitation appears to confer minimal effect on asthma control, although the certainty of evidence is very low to low. Unclear reporting of study methods and small sample sizes limits our certainty in the overall body of evidence, whilst heterogenous study designs and interventions likely contribute to inconsistent findings across clinical outcomes and studies. There remains considerable scope for future research.

A Systematic Review of the Effect of Physical Activity on Asthma Outcomes

BACKGROUND

Asthma is a chronic respiratory disease that affects millions worldwide. Medication management is the current mainstay of treatment; however, there is evidence to suggest additional benefit with lifestyle changes, particularly with increased physical activity.

OBJECTIVE

To discover and evaluate the effects of physical activity on asthma outcomes.

METHODS

Systematic search of PubMed, Excerpta Medica database, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, Rehabilitation and Sports Medicine Source, Scopus, and Web of Science identified 11,155 results. Thirty-five articles met our inclusion criteria spanning 20 studies. Data extraction was conducted by 6 independent reviewers, and final results were evaluated by a seventh reviewer and the senior author.

RESULTS

Wide variation among selected studies, including the heterogeneity of interventions and outcome variables, did not support a meta-analysis. Mixed results of the effects of physical activity on asthma outcomes were found. Most studies suggest that physical activity improves asthma control, quality of life, lung function parameters, and inflammatory serologies, whereas 3 found no improvements in any of these outcomes. No studies reported worsening asthma outcomes.

CONCLUSIONS

This review highlights the emerging and promising role of physical activity as a nonpharmacologic treatment for asthma. Additional high-quality randomized controlled trials are needed to overcome the problems of measurement heterogeneity and the dilution of outcome effect size measurement related to physical activity interventions for asthma.

Effect of Running Exercise on Oxidative Stress Biomarkers: A Systematic Review

Background: Exercise induced health benefits are limited by the overaccumulation of reactive oxygen species (ROS). ROS and further oxidative stress could potentially induce muscle damage which could result in poor exercise performance. However, predicting ROS induced oxidative stress in response to endurance training has several limitations in terms of selecting biomarkers that are used to measure oxidative stress.

Objective: The purpose of this study was to systematically investigate the suitable biomarkers that predict oxidative stress status among runners.

Methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a search for relevant articles was carried out on PubMed/Medline, ISI Web of Science, and Google Scholar using related search terms such as oxidative damage, ROS, exercise, physical training, running, marathon, and ultramarathon.

Results: Outcomes included (1) running programs like a half-marathon, ultramarathon, and iron-man race, (2) measuring biochemical assessment of oxidative damage markers such as malondialdehyde (MDA), protein carbonyl (PC), total antioxidant capacity (TAC), thiobarbituric acid reactive substances (TBARS), 8-Oxo-2'-deoxyguanosine (8-OH-dG), 4-hydroxynonenal (HNE), and F1-isoprostones, and enzymatic and non-enzymatic antioxidants level.

Conclusions: This study concluded that a running exercise does not elicit a response to specific biomarkers of oxidative stress, instead, oxidative damage markers of lipids, proteins, and various enzymatic and non-enzymatic antioxidants are expressed according to the training status of the individual.

Can training induce inflammatory control in asthma, or is it symptom control only?

PURPOSE OF REVIEW

Exercise has shown to reduce asthma symptoms; however, the underlying mechanism for this improvement remains unclear. Improvement in inflammatory control could be the reason for this reduction in symptoms. This review discusses recent studies evaluating the effect of exercise on inflammatory control in patients with asthma.

RECENT FINDINGS

New studies support that exercise is well tolerated and feasible regardless of intensity. Exercise seems to improve systemic low-grade inflammation, but consistency lacks when it comes to reduction in airway inflammation.

SUMMARY

Physical exercise as an adjuvant therapy leads to improvement in asthma symptoms and asthma-related quality of life and should be recommended for all patients with asthma.

Winter Exercise and Speleotherapy for Allergy and Asthma: A Randomized Controlled Clinical Trial

(1) Background: The prevalence of allergic respiratory diseases is still rising and efforts towards holistic treatments should be made. Although speleotherapy is widely applied in Europe to treat chronic airway diseases, the existing scientific evidence is rather low. Recreational winter exercise has been shown to improve allergic airway inflammation, but little is known about the combined effects of speleotherapy and recreational winter exercise. (2) Methods: In this clinical study we investigated the effects of winter exercise and speleotherapy on adults with allergic rhinitis and/or asthma. The speleotherapy group (n = 23) participated in a ten-day combined winter exercise and speleotherapy program and the exercise group (n = 18) joined a full-day winter sports program. The effects on allergic airway inflammation, quality of life, spirometry and cardiorespiratory fitness were assessed. (3) Results: No significant effects were found for fractional exhaled nitric oxide or nasal nitric oxide. Quality of life (p < 0.001 time effect) and allergic symptoms (p < 0.001 time effect) were improved in the speleotherapy and in the exercise group. (4) Conclusions: Winter exercise alone and winter exercise in combination with speleotherapy improve quality of life and allergic symptoms in adults with allergic rhinitis and/or asthma. Further studies are required to investigate the specific effects of speleotherapy. To our knowledge, this is the first investigation examining speleotherapy in combination with winter exercise. Recreational outdoor winter exercise and speleotherapy may be recommended for highly functioning patients with good disease control.

The impact of exercise on asthma

PURPOSE OF REVIEW

Asthma is one of the most common chronic diseases in children and adults in developed countries around the world. Despite international treatment guidelines, poor asthma control remains a frequent problem leading to missed school and work, and emergency room visits and hospitalizations. Many patients with asthma report exercise as a trigger for their asthma, which likely leads to exercise avoidance as a means to control symptoms. Evolving research has suggested that routine exercise may actually help improve some aspects of asthma control. This review discusses the recent research addressing how routine exercise affects important asthma-related outcomes including symptoms, lung function and quality of life.

RECENT FINDINGS

Several systematic reviews and meta-analyses have been conducted in recent years, which strongly support the safety of routine exercise in children and adults with asthma. Exercise appears to favor improvements in aerobic fitness, asthma symptoms and quality of life, but results so far are less consistent in demonstrating improvements to lung function and airway hyperresponsiveness.

SUMMARY

In addition to routine management guidelines, clinicians should recommend for their patients with asthma routine exercise for its general health benefits and likely improvement in asthma symptoms and quality of life.

Physical Activity: A Missing Link in Asthma Care

Asthma is the commonest respiratory disease and one of unceasingly increasing prevalence and burden. As such, asthma has attracted a major share or scientific interest and clinical attention. With the various clinical and pathophysiological aspects of asthma having been extensively investigated, the important association between asthma and physical activity remains underappreciated and insufficiently explored. Asthma impacts adversely on physical activity. Likewise, poor physical activity may lead to worse asthma outcomes. This concise clinical review presents the current recommendations for physical activity, discusses the available evidence on physical activity in asthma, and examines the causes of low physical activity in adult asthmatic patients. It also reviews the effect of daily physical activity and exercise training on the pathology and clinical outcomes of asthma. Finally, it summarizes the evidence on interventions targeting physical activity in asthma.

Deep inspirations attenuate postprandial airway inflammation in college-aged adults with elevated baseline exhaled nitric oxide: A pilot study

Airway inflammation (assessed by exhaled nitric oxide (eNO)) increases after a single high-fat meal (HFM), yet this response may be modified by airway stretch and baseline eNO level.Purpose: The purpose of this study was to investigate whether deep inspirations (DIs) would attenuate airway inflammation post-HFM and whether this is modulated by baseline eNO level.Methods: A total of sixteen healthy college-aged participants completed a randomized cross-over study with 8 lower eNO (14.8 ± 2.0 ppb: 3 M/5F; age: 22.0 ± 2.2 yrs) and 8 higher eNO (29.3 ± 11.6 ppb 5 M/3F; age: 22.5 ± 2.6 yrs) participants. All participants completed a control (CON) condition (no DIs pre-HFM) and DI condition (60 DI's to total lung capacity immediately pre-HFM) after an overnight fast. The primary outcome was eNO. Participants had 20 minutes to consume the HFM (1 g fat/1 kg body weight) and eNO was performed at 2- and 4- hours post-HFM. To determine whether baseline eNO levels impacted the effect of DI's, a median split was performed on their baseline eNO level.Results: There was a significant increase in eNO as a main effect of time (p < 0.001). However when analyzing the potential effect of baseline eNO, there was no significant increase in eNO post-HFM in the higher eNO group in the DI condition (p = 0.54). DIs modified the eNO response to a HFM in the group with a higher baseline eNO value.Conclusions: These data display a possible bronchoprotective protect of DIs against postprandial airway inflammation in participants with higher initial eNO level.

Winter Exercise Reduces Allergic Airway Inflammation: A Randomized Controlled Study

Background: Physical exercise is often recommended as additional treatment for people suffering from allergic rhinitis and/or asthma, but less is known about the specific effects of recreational winter outdoor exercise on allergic airway inflammation. Methods: We performed a longitudinal, randomized controlled intervention study to investigate the effects of recreational winter exercise on allergic airway inflammation, quality of life, spirometry and cardiorespiratory fitness in adults suffering from allergic rhinitis and/or asthma. The exercise group participated in a ten-day winter sports program. The control group did not receive any intervention. Results: A significant improvement of fractional oral exhaled nitric oxide (FeNO; p = 0.008, day 10) and a significant decrease in FeNO after a single 4 h hiking tour (p < 0.001, time effect) were observed for the exercise group. The nasal eosinophilic cell count revealed a short-term reduction (p = 0.021, treatment effect) in the exercise group and for the visual analogue scale sustainable improvements in allergic symptoms (p < 0.001, day 60) were found. No adverse effects of outdoor winter exercise were observed. Conclusion: Recreational winter exercise at moderately cold temperatures reduces allergic airway inflammation measured as FeNO, nasal eosinophilic cell count and induces sustainable improvements in allergic symptoms.

Exercise Mediated Nrf2 Signaling Protects the Myocardium From Isoproterenol-Induced Pathological Remodeling

Although exercise derived activation of Nrf2 signaling augments myocardial antioxidant signaling, the molecular mechanisms underlying the benefits of moderate exercise training (MET) in the heart remain elusive. Here we hypothesized that exercise training stabilizes Nrf2-dependent antioxidant signaling, which then protects the myocardium from isoproterenol-induced damage. The present study assessed the effects of 6 weeks of MET on the Nrf2/antioxidant function, glutathione redox state, and injury in the myocardium of C57/BL6J mice that received isoproterenol (ISO; 50 mg/kg/day for 7 days). ISO administration significantly reduced the Nrf2 promoter activity (p < 0.05) and downregulated the expression of cardiac antioxidant genes (Gclc, Nqo1, Cat, Gsr, and Gst-μ) in the untrained (UNT) mice. Furthermore, increased oxidative stress with severe myocardial injury was evident in UNT+ISO when compared to UNT mice receiving PBS under basal condition. Of note, MET stabilized the Nrf2-promoter activity and upheld the expression of Nrf2-dependent antioxidant genes in animals receiving ISO, and attenuated the oxidative stress-induced myocardial damage. Echocardiography analysis revealed impaired diastolic ventricular function in UNT+ISO mice, but this was partially normalized in the MET animals. Interestingly, while there was a marginal reduction in ubiquitinated proteins in MET mice that received ISO, the pathological signs were attenuated along with near normal cardiac function in response to exercise training. Thus, moderate intensity exercise training conferred protection against ISO-induced myocardial injury by augmentation of Nrf2-antioxidant signaling and attenuation of isoproterenol-induced oxidative stress.

Acute Effects Using Light-Emitting Diode Therapy (LEDT) for Muscle Function during Isometric Exercise in Asthma Patients: A Pilot Study

The aim of this study was to evaluate the effectiveness of acute application of LEDT in improving peripheral muscle performance during isometric exercise in patients with asthma. Eleven patients, with a mean age 38 ± 10, underwent a single LEDT and sham application in the femoral quadriceps' dominant member (cluster with 50 LED λ = 850 nm, 50 mW, 15 s; 37.5 J), 48 h apart in a randomized crossover design. Before and after LEDT and sham application, the patients were submitted an isometric endurance test (60% of the maximum isometric voluntary contraction), up to the limit of tolerance simultaneous recording of surface electromyography. There were no statistically significant differences between groups at the time of contraction (before 41±14 versus 44±16; after 46±12 versus 45±20 s) during the isometric contraction test and inflammatory markers before and after a single LEDT application. A single application of LEDT in the parameters and dose according to the equipment used in the study were not able to promote differences in the time of contraction and the fatigue response in asthmatic patients. However, the chronic effects of LEDT application for improving muscle performance in these patients are unknown and may present different responses during applications for a long time.

Nrf2-Keap1 signaling in oxidative and reductive stress

Nrf2 and its endogenous inhibitor, Keap1, function as a ubiquitous, evolutionarily conserved intracellular defense mechanism to counteract oxidative stress. Sequestered by cytoplasmic Keap1 and targeted to proteasomal degradation in basal conditions, in case of oxidative stress Nrf2 detaches from Keap1 and translocates to the nucleus, where it heterodimerizes with one of the small Maf proteins. The heterodimers recognize the AREs, that are enhancer sequences present in the regulatory regions of Nrf2 target genes, essential for the recruitment of key factors for transcription. In the present review we briefly introduce the Nrf2-Keap1 system and describe Nrf2 functions, illustrate the Nrf2-NF-κB cross-talk, and highlight the effects of the Nrf2-Keap1 system in the physiology and pathophysiology of striated muscle tissue taking into account its role(s) in oxidative stress and reductive stress.

Nrf2 mediates redox adaptations to exercise

The primary aim of this review is to summarize the current literature on the effects of acute exercise and regular exercise on nuclear factor erythroid 2-related factor 2 (Nrf2) activity and downstream targets of Nrf2 signaling. Nrf2 (encoded in humans by the NFE2L2 gene) is the master regulator of antioxidant defenses, a transcription factor that regulates expression of more than 200 cytoprotective genes. Increasing evidence indicates that Nrf2 signaling plays a key role in how oxidative stress mediates the beneficial effects of exercise. Episodic increases in oxidative stress induced through bouts of acute exercise stimulate Nrf2 activation and when applied repeatedly, as with regular exercise, leads to upregulation of endogenous antioxidant defenses and overall greater ability to counteract the damaging effects of oxidative stress. The evidence of Nrf2 activation in response to exercise across variety of tissues may be an important mechanism of how exercise exerts its well-known systemic effects that are not limited to skeletal muscle and myocardium. Additionally there are emerging data that results from animal studies translate to humans.

Diurnal Variation of Circulating Interleukin-6 in Humans: A Meta-Analysis

The pleiotropic cytokine interleukin-6 (IL-6) has been proposed to contribute to circadian regulation of sleepiness by increasing in the blood at night. Earlier studies have reported diurnal variation of IL-6, but phase estimates are conflicting. We have therefore performed a meta-analysis on the diurnal variation of circulating IL-6. Studies were included if they reported IL-6 in plasma or serum recorded at least twice within 24 hours in the same individual. A systematic search resulted in the inclusion of 43 studies with 56 datasets, for a total of 1100 participants. Individual participant data were available from 4 datasets with a total of 56 participants. Mixed-effects meta-regression modelling confirmed that IL-6 varied across the day, the most conspicuous effect being a trough in the morning. These results stand in contrast to earlier findings of a peak in the evening or night, and suggest that diurnal variation should be taken into account in order to avoid confounding by time of day in studies of IL-6 in plasma or serum.

Does chronic physical activity level modify the airway inflammatory response to an acute bout of exercise in the postprandial period?

Recent studies have confirmed that a single high-fat meal (HFM) leads to increased airway inflammation. However, exercise is a natural anti-inflammatory and may modify postprandial airway inflammation. The postprandial airway inflammatory response is likely to be modified by chronic physical activity (PA) level. This study investigated whether chronic PA modifies the airway inflammatory response to an acute bout of exercise in the postprandial period in both insufficiently active and active subjects. Thirty-nine nonasthmatic subjects (20 active, 13 males/7 females) who exceeded PA guidelines (≥150 min moderate-vigorous PA/week) and 19 insufficiently active (6 males/13 females) underwent an incremental treadmill test to exhaustion to determine peak oxygen uptake. Subjects were then randomized to a condition (COND), either remaining sedentary (CON) or exercising (EX) post-HFM. Exercise was performed at the heart rate corresponding to 60% peak oxygen uptake on a treadmill for 1 h post-HFM (63% fat, 10 kcal/kg body weight). Blood lipids and exhaled nitric oxide (eNO: marker of airway inflammation) were measured at baseline and 2 h and 4 h post-HFM. Sputum differential cell counts were performed at baseline and 4 h post-HFM. The mean eNO response for all groups increased at 2 h post-HFM (∼6%) and returned to baseline by 4 h (p = 0.03). There was a time × COND interaction (p = 0.04), where EX had a greater eNO response at 4 h compared with CON. Sputum neutrophils increased at 4 h post-HFM (p < 0.05). These findings suggest that airway inflammation occurs after an HFM when exercise is performed in the postprandial period, regardless of habitual activity level.

Decreased physical activity in adults with bronchial asthma

Contradictory findings have been reported in the literature on the impact that bronchial asthma may have on habitual physical activity. The present study was designed to compare physical activity, objectively measured with an activity monitor, between adults with bronchial asthma and apparently healthy controls. Valid registrations of physical activity were obtained in 226 patients with asthma and 201 healthy controls. A multiple general linear model was used to test between group differences and to correct for confounding of the results due to between group differences in BMI and employment status. In the patients, statistically significantly lower values were found for average steps/day (-1202; CI -1893 to -511; P = 0.001), physical activity level based on an estimate of a person's total energy expenditure (-0.035; CI -0.067 to -0.003); P = 0.034) and daily time (minutes) spent at vigorous intensive physical activity (-11; CI -17 to -1; P < 0.001). In addition, weak albeit significant correlations were found between measures of physical activity and asthma control. We conclude that bronchial asthma in adults is associated with a significant reduction in physical activity as compared to apparently healthy controls and is accompanied by a lower perceived health status. This is in support of the postulation of PA as potential pathway to better the outcome of care for these patients.