Physical activity and bronchial hyperresponsiveness: European Community Respiratory Health Survey II

Association between physical activity and multimorbidity: a population-based cohort study

BACKGROUND

Physical activity has been widely recognized for its important role in preventing cardiovascular and other chronic diseases. While population studies worldwide have established clear associations between physical activity and multimorbidity, these relationships in the Chinese population remain underexplored.

METHODS

This study utilized the China Health and Retirement Longitudinal Study (CHARLS) database to classify physical activity levels based on metabolic equivalents (MET). Physical activity was measured using self-reported questionnaires based on the International Physical Activity Questionnaire (IPAQ). The analysis focused on the relationship between low, moderate, and high physical activity levels and various chronic diseases, as well as the co-occurrence of multiple diseases. Multivariable logistic regression models were employed to assess the association between different activity levels and the risk of chronic diseases, while stratified analyses explored the impact of demographic factors on these associations. Additionally, a restricted cubic spline (RCS) model was applied to investigate potential nonlinear relationships between total MET and chronic disease risks.

RESULTS

The final cohort included 6,244 participants with a total of 19,498 observations across five waves (2011-2020). The results showed that compared to low activity levels, moderate and high levels of physical activity reduced the risk of cardiovascular diseases and respiratory diseases, with a nonlinear dose-response relationship. High levels of physical activity also significantly lowered the risk of multimorbidity, particularly the coexistence of five or more chronic diseases (OR = 0.58, 95% CI: 0.46, 0.74, P < 0.01). However, high levels of activity were linked to higher risks of arthritis and kidney diseases. Stratified analyses revealed that demographic factors influenced the association between physical activity and disease risk.

CONCLUSION

Moderate and high levels of physical activity provide significant protection against cardiovascular and respiratory diseases and effectively reduce the risk of multimorbidity. However, the increased risk of certain metabolic and joint diseases with higher activity levels warrants further attention. Future research should clarify the impact of physical activity on different populations and chronic diseases, with randomized controlled trials needed to verify causality.

Causal associations of self-reported walking pace with respiratory diseases: A Mendelian randomization analysis

Although studies have indicated causality between brisk walking and various diseases, the relationships between walking pace and respiratory diseases lack thorough investigation. The underlying relationships between walking pace and various respiratory diseases were examined through univariable Mendelian randomization (MR) analyses. Furthermore, we performed multivariable MR analyses to observe whether relationships between walking pace and respiratory diseases change after adjustment of body mass index (BMI). The genome-wide association study data of self-reported walking pace, BMI, and 42 respiratory diseases were retrieved from publicly available datasets. We employed the inverse-variance weighted, weighted median, and MR-Egger methods for MR analysis. Using the inverse-variance weighted method in univariable MR, we identified statistically significant negative causal associations between self-reported walking pace and 4 respiratory traits, including chronic lower respiratory diseases (odds ratio [OR], 0.27 [95% confidence interval [CI], 0.18-0.41]), asthma (OR, 0.23 [95% CI, 0.14-0.38]), chronic obstructive pulmonary disease (OR, 0.15 [95% CI, 0.08-0.30]), and diseases of the respiratory system (OR, 0.54 [95% CI, 0.41-0.70]). Similar results were observed with the MR-Egger and weighted median methods. These associations remained significant, though slightly attenuated, after adjusting for BMI. A brisk walking pace may significantly benefit respiratory health and aid in disease prevention and risk stratification.

The Joint Association of Sleep Quality and Outdoor Activity with Asthma and Allergic Rhinitis in Children: A Cross-Sectional Study in Shanghai

Purpose

Aiming to investigate the combined association of sleep quality and outdoor activity with the risk of asthma and allergic rhinitis in children.

Patients and Methods

16,936 children from kindergartens and primary schools in 13 administrative districts of Shanghai, China were involved in the analyses. The Children's Sleep Habits Questionnaire (CSHQ) and the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire were respectively used to evaluate the sleep quality, allergic rhinitis and asthma. Multivariable logistic regression models were used to analyze the correlation of sleep quality, outdoor activities and their combination with children's asthma and allergic rhinitis.

Results

The overall prevalence of asthma and allergic rhinitis in our sampled children were 10.2% and 17.6%, respectively. Poor sleep quality (asthma: aOR, 1.45; 95% CI: 1.23 to 1.73; allergic rhinitis: aOR, 1.16; 95% CI: 1.03 to 1.31) and low outdoor activity (asthma: aOR, 1.30; 95% CI: 1.14 to 1.49, allergic rhinitis: aOR, 1.18; 95% CI: 1.07 to 1.32) were separately associated with higher risk of asthma and allergic rhinitis, and when the two were superimposed, an additive effect (asthma: aOR, 1.76; 95% CI: 1.30 to 2.39; allergic rhinitis: aOR, 1.46; 95% CI: 1.17 to 1.82) was revealed. These associations were independent of sleep duration, but being stronger in sleep sufficiency group. And after stratification by gender, premature birth and family history of allergy, similar associations were validated in general.

Conclusion

Poor sleep quality and low levels of outdoor activity, when combined, have a stronger association with asthma and allergic rhinitis than each factor independently, and this relationship is not influenced by sleep duration. Our findings highlight the need for public health interventions that simultaneously address multiple lifestyle factors to reduce the risk of allergic diseases.

When and where to exercise: An assessment of personal exposure to urban tropical ambient airborne pollutants in Singapore

BACKGROUND

Physical activity is associated with health benefits and has been shown to reduce mortality risk. However, exposure to high levels of ambient fine particulate matter (PM2.5) during exercise can potentially reduce the health benefits of physical activity. This study aims to assess and compare the PM2.5 concentrations of different exercise venues in Singapore by their location attributes and time of day.

METHODS

Personal PM2.5 exposures (μg/m3) at 24 common outdoor exercise venues in Singapore over 49 sampling days were collected using real-time personal sensors from September 2017 to January 2020. Wilcoxon rank-sum test and Kruskal-Wallis test were used to compare PM2.5 concentrations between different timings (peak (0700-0900; 1800-2000) vs. non-peak (0600-0700; 0900-1800; 2000-2300); weekend vs. weekday), and location attributes (near major roads (<50 m) vs. away from major roads (≥50 m)). Multivariable linear regression models were used to assess the associations between location attributes, timings and ambient PM2.5 with personal PM2.5 concentration, adjusting for potential confounders.

RESULTS

Compared with peak hours, exercising during non-peak hours was associated with a significantly lower PM2.5 exposure (median, 17.8 μg/m3 during peak vs. 14.5 μg/m3 during non-peak; P = 0.006). Exercise venues away from major roads have significantly lower PM2.5 concentrations as compared to those located next to major roads (median, 14.4 μg/m3 away from major roads vs. 18.5 μg/m3 next to major roads; P < 0.001). Individuals who exercised in parks experienced the highest PM2.5 exposure (median, 55.0 μg/m3) levels in the afternoon during 1400-1500. Furthermore, ambient PM2.5 concentration was significantly and positively associated with personal PM2.5 exposure (β = 0.85, P < 0.001).

CONCLUSIONS

Our findings suggest that exercising outdoors in the urban environment exposes individuals to differential levels of PM2.5 at different times of the day. Further research should investigate a wider variety of outdoor exercise venues, explore different types of air pollutants, and consider the varying activity patterns of individuals.

Six-minute walk distance in healthy subjects: reference standards from a general population sample

Introduction

The 6-min walking distance (6MWD) test is a useful tool to obtain a measure of functional exercise capacity. However, reference equations have been mainly based on selected populations or small samples. The purpose of this study was to determine the reference equations to predict the 6MWD in a large Italian population sample of healthy adults of a wide age range.

Methods

In the frame of the multi case–control population-based study Gene Environment Interaction in Respiratory Diseases (GEIRD), we studied 530 healthy subjects: 287 females ranging 21–76 and 243 males ranging 21–78 years of age. We measured 6MWD, demographic and anthropometric data and collected the reported physical activity. A multiple linear regression model for the 6MWD included age, age², height, weight and physical activity for both sex equations. The two-way interaction age-height and age-weight and the quadratic terms of weight and height were also tested for inclusion separately in each model.

Results

The mean ± SD for 6MWD was 581.4 ± 66.5 m (range 383–800 m) for females and 608.7 ± 80.1 m (range 410–875 m) for males. The reference equations were 6MWD = 8.10*age + 1.61*height_cm−0.99*weight_kg + 22.58*active−0.10*age² + 222.55 for females (R squared = 0.238) and 6MWD = 26.80*age + 8.46*height_cm−0.45*weight_kg−2.54*active−0.06*age²−0.13*age*height_cm−890.18 for males (R squared = 0.159), where “active” is 1 when the subject is physically active, 0 otherwise.

Conclusion

This study is the first to describe the 6MWD in a large population sample of young, middle aged and elderly healthy Caucasian subjects, and to determine reference equations. These findings will help to improve the evaluation of Italian and European patients with diseases influencing their functional capacity.

[Novelties in the Treatment of Asthma]

Novelties in the Treatment of Asthma Abstract. For general practitioners there have been important novelties in the treatment of asthma due to recent modifications of the international guidelines from Global Initiative for Asthma (GINA). Step 1 no longer recommends the use of short-acting β2-agonists (SABA) without concomitant inhaled corticosteroids (ICS) as a controller because of the lack of efficacy and for safety reasons. Instead, low dose ICS-formoterol as needed is recommended. GINA step 5 recommends targeted biologic therapies like interleukin antibodies in patients with severe uncontrolled asthma. Asthma patients presenting simultaneously with symptoms of chronic obstructive pulmonary disease (COPD) should receive treatment containing ICS. Independent of the current corona pandemic, GINA recommendations stay in place. Recent data on prescriptions of SABA and oral corticosteroids (OCS) in Switzerland indicate that they still play an important role in asthma management and that GINA recommendations have not yet been sufficiently implemented into practice.

Regular Physical Activity Levels and Incidence of Restrictive Spirometry Pattern: A Longitudinal Analysis of 2 Population-Based Cohorts

We estimated the association between regular physical activity and the incidence of restrictive spirometry pattern. Forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and physical activity were assessed in 2 population-based European cohorts (European Community Respiratory Health Survey: n = 2,757, aged 39-67 years; and Swiss Study on Air Pollution and Lung and Heart Diseases in Adults: n = 2,610, aged 36-82 years) first in 2000-2002 and again approximately 10 years later (2010-2013). Subjects with restrictive or obstructive spirometry pattern at baseline were excluded. We assessed the association of being active at baseline (defined as being physically active at least 2-3 times/week for ≥1 hour) with restrictive spirometry pattern at follow-up (defined as a postbronchodilation FEV1/FVC ratio of at least the lower limit of normal and FVC of <80% predicted) using modified Poisson regression, adjusting for relevant confounders. After 10 years of follow-up, 3.3% of participants had developed restrictive spirometry pattern. Being physically active was associated with a lower risk of developing this phenotype (relative risk = 0.76, 95% confidence interval: 0.59, 0.98). This association was stronger among those who were overweight and obese than among those of normal weight (P for interaction = 0.06). In 2 large European studies, adults practicing regular physical activity were at lower risk of developing restrictive spirometry pattern over 10 years.

Effect of Creatine Supplementation on the Airways of Youth Elite Soccer Players

Introduction

Owing to its well-established ergogenic potential, creatine is a highly popular food supplement in sports. As an oral supplement, creatine is considered safe and ethical. However, no data exist on the safety of creatine on lung function in athletes. The aim of this project was to evaluate the effects of a standard course of creatine on the airways of youth elite athletes.

Methods

Nineteen elite soccer players, 16–21 yr old, completed a stratified, randomized, double-blind, placebo-controlled, parallel-group trial. The creatine group (n = 9) ingested 0.3 g·kg⁻¹⋅d⁻¹ of creatine monohydrate (CM) for 1 wk (loading phase) and 5 g·d⁻¹ for 7 wk (maintenance phase), and the placebo group (n = 10) received the same dosages of maltodextrin. Airway inflammation (assessed by exhaled nitric oxide, F_ENO) and airway responsiveness (to dry air hyperpnoea) were measured pre- and postsupplementation.

Results

Mild, unfavorable changes in F_ENO were noticed by trend over the supplementation period in the CM group only (P = 0.056 for interaction, η² = 0.199), with a mean group change of 9 ± 13 ppb in the CM group versus −5 ± 16 ppb in the placebo group (P = 0.056, d = 0.695). Further, the maximum fall in forced expiratory volume in 1 s after dry air hyperpnoea was larger by trend postsupplementation in the CM group compared with the placebo group: 9.7% ± 7.5% vs 4.4% ± 1.4%, respectively (P = 0.070, d = 0.975). These adverse effects were more pronounced when atopic players only (n = 15) were considered.

Conclusion

On the basis of the observed trends and medium to large effect sizes, we cannot exclude that creatine supplementation has an adverse effect on the airways of elite athletes, particularly in those with allergic sensitization. Further safety profiling of the ergogenic food supplement is warranted.

Asthma, exercise and metabolic dysregulation in paediatrics

Asthma is the most frequent chronic disease in childhood. Chest tightness, cough, wheezing and dyspnoea during or after exercise may be unique manifestations of asthma in up to 90% of subjects. Physical activity may be reduced by uncontrolled asthma symptoms and parental beliefs, impairing physical fitness of asthmatic children. Clinicians working in the field of allergy are aware of evidence supporting the benefits of physical activity for patients with asthma. Treatment of asthma is required in order to obtain its control and to avoid any limitation in sports and active play participation. As exercise performance in children with controlled asthma is not different from that of healthy controls, any exercise limitation cannot be accepted. Overweight and obesity may interfere with asthma and exercise, leading to dyspnoea symptoms. Evidences on the effect of insulin resistance on airway smooth muscle and on bronchial hyperactivity are presented. CONCLUSION: Exercise is part of the strategy to obtain the best control of asthma in childhood, but we have to optimise the asthma control therapy before starting exercise programming. Furthermore, it is crucial to give best attention on the effects of obesity and insulin resistance, because they could in turn influence patients' symptoms.

Restrictive spirometry pattern is associated with low physical activity levels. A population based international study

INTRODUCTION

Restrictive spirometry pattern is an under-recognised disorder with a poor morbidity and mortality prognosis. We compared physical activity levels between adults with a restrictive spirometry pattern and with normal spirometry.

METHODS

Restrictive spirometry pattern was defined as a having post-bronchodilator FEV₁/FVC ≥ Lower Limit of Normal and a FVC<80% predicted in two population-based studies (ECRHS-III and SAPALDIA3). Physical activity was measured using the International Physical Activity Questionnaire. The odds of having low physical activity (<1st study-specific tertile) was evaluated using adjusted logistic regression models.

RESULTS

Subjects with a restrictive spirometry pattern (n = 280/4721 in ECRHS, n = 143/3570 in SAPALDIA) reported lower levels of physical activity than those with normal spirometry (median of 1770 vs 2253 MET·min/week in ECRHS, and 3519 vs 3945 MET·min/week in SAPALDIA). Subjects with a restrictive spirometry pattern were more likely to report low physical activity (meta-analysis odds ratio: 1.41 [95%CI 1.07-1.86]) than those with a normal spirometry. Obesity, respiratory symptoms, co-morbidities and previous physical activity levels did not fully explain this finding.

CONCLUSION

Adults with a restrictive spirometry pattern were more likely to report low levels of physical activity than those with normal spirometry. These results highlight the need to identify and act on this understudied but prevalent condition.

Residential air pollution does not modify the positive association between physical activity and lung function in current smokers in the ECRHS study

BACKGROUND

Very few studies have examined whether a long-term beneficial effect of physical activity on lung function can be influenced by living in polluted urban areas.

OBJECTIVE

We assessed whether annual average residential concentrations of nitrogen dioxide (NO₂) and particulate matter with aerodynamic diameters < 2.5 μm (PM_2.5) and <10 μm (PM₁₀) modify the effect of physical activity on lung function among never- (N = 2801) and current (N = 1719) smokers in the multi-center European Community Respiratory Health Survey.

METHODS

Associations between repeated assessments (at 27-57 and 39-67 years) of being physically active (physical activity: ≥2 times and ≥1 h per week) and forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) were evaluated using adjusted mixed linear regression models. Models were conducted separately for never- and current smokers and stratified by residential long-term NO₂, PM_2.5 mass and PM₁₀ mass concentrations (≤75th percentile (low/medium) versus >75th percentile (high)).

RESULTS

Among current smokers, physical activity and lung function were positively associated regardless of air pollution levels. Among never-smokers, physical activity was associated with lung function in areas with low/medium NO₂, PM_2.5 mass and PM₁₀ mass concentrations (e.g. mean difference in FVC between active and non-active subjects was 43.0 mL (13.6, 72.5), 49.5 mL (20.1, 78.8) and 49.7 mL (18.6, 80.7), respectively), but these associations were attenuated in high air pollution areas. Only the interaction term of physical activity and PM₁₀ mass for FEV₁ among never-smokers was significant (p-value = 0.03).

CONCLUSIONS

Physical activity has beneficial effects on adult lung function in current smokers, irrespective of residential air pollution levels in Western Europe. Trends among never-smokers living in high air pollution areas are less clear.

Leisure-time vigorous physical activity is associated with better lung function: the prospective ECRHS study

OBJECTIVE

We assessed associations between physical activity and lung function, and its decline, in the prospective population-based European Community Respiratory Health Survey cohort.

METHODS

FEV₁ and FVC were measured in 3912 participants at 27-57 years and 39-67 years (mean time between examinations=11.1 years). Physical activity frequency and duration were assessed using questionnaires and used to identify active individuals (physical activity ≥2 times and ≥1 hour per week) at each examination. Adjusted mixed linear regression models assessed associations of regular physical activity with FEV₁ and FVC.

RESULTS

Physical activity frequency and duration increased over the study period. In adjusted models, active individuals at the first examination had higher FEV₁ (43.6 mL (95% CI 12.0 to 75.1)) and FVC (53.9 mL (95% CI 17.8 to 89.9)) at both examinations than their non-active counterparts. These associations appeared restricted to current smokers. In the whole population, FEV₁ and FVC were higher among those who changed from inactive to active during the follow-up (38.0 mL (95% CI 15.8 to 60.3) and 54.2 mL (95% CI 25.1 to 83.3), respectively) and who were consistently active, compared with those consistently non-active. No associations were found for lung function decline.

CONCLUSION

Leisure-time vigorous physical activity was associated with higher FEV₁ and FVC over a 10-year period among current smokers, but not with FEV₁ and FVC decline.

Physical activity and asthma: A longitudinal and multi-country study

OBJECTIVE

To investigate the impact of physical activity on asthma in middle-aged adults, in one longitudinal analysis, and one multi-centre cross-sectional analysis.

METHODS

The Respiratory Health in Northern Europe (RHINE) is a population-based postal questionnaire cohort study. Physical activity, height and weight were self-reported in Bergen, Norway, at RHINE II (1999-2001) and all centres at RHINE III (2010-2012). A longitudinal analysis of Bergen data investigated the association of baseline physical activity with follow-up asthma, incident asthma and symptoms, using logistic and zero-inflated Poisson regression (n = 1782). A cross-sectional analysis of all RHINE III centres investigated the association of physical activity with concurrent asthma and symptoms (n = 13,542) using mixed-effects models. Body mass index (BMI) was categorised (<20, 20-24.99, 25-29.99, 30+ kg/m²) and physical activity grouped by amount and frequency of lighter (no sweating/heavy breathing) and vigorous (sweating/heavy breathing) activity.

RESULTS

In the Bergen longitudinal analysis, undertaking light activity 3+ times/week at baseline was associated with less follow-up asthma (odds ratio [OR] 0.44, 95% confidence interval [CI] 0.22, 0.89), whilst an effect from undertaking vigorous activity 3+ times/week was not detected (OR 1.22, 95% CI 0.44, 2.76). The associations were attenuated with BMI adjustment. In the all-centre cross-sectional analysis an interaction was found, with the association between physical activity and asthma varying across BMI categories.

CONCLUSION

These findings suggest potential longer-term benefit from lighter physical activity, whilst improvement in asthma outcomes from increasing activity intensity was not evident. Additionally, it appears the benefit from physical activity may differ according to BMI.

Physical activity and lung function decline in adults with asthma: The HUNT Study

BACKGROUND AND OBJECTIVE

People with asthma may seek advice about physical activity. However, the benefits of leisure time physical activity on lung function are unclear. We investigated the association between leisure time physical activity and lung function decline in adults with asthma.

METHODS

In a population-based cohort study in Norway, we used multiple linear regressions to estimate the annual mean decline in lung function (and 95% CI) in 1329 people with asthma over a mean follow-up of 11.6 years. The durations of light and hard physical activity per week in the last year were collected by questionnaire. Inactive participants did not report any light or hard activity, while active participants reported light or hard activity.

RESULTS

The mean decline in forced expiratory volume in 1 s (FEV₁ ) was 37 mL/year among inactive participants and 32 mL/year in active participants (difference: -5 mL/year (95% CI: -13 to 3)). The mean decline in forced vital capacity (FVC) was 33 mL/year among inactive participants and 31 mL/year in active participants (difference: -2 mL/year (95% CI: -11 to 7)). The mean decline in FEV₁ /FVC ratio was 0.36%/year among inactive participants and 0.22%/year in active participants (difference: -0.14%/year (95% CI: -0.27 to -0.01)). The mean decline in peak expiratory flow (PEF) was 14 mL/year among the inactive participants and 10 mL/year in active participants (difference: -4 mL/year (95% CI: -9 to 1)).

CONCLUSION

We observed slightly less decline in lung function in physically active than inactive participants with asthma, particularly for FEV₁ , FEV₁ /FVC ratio and PEF.

Endurance training: is it bad for you?

Educational aims

Endurance exercise training exerts many positive effects on health, including improved metabol­ism, reduction of cardiovascular risk, and reduced all-cause and cardiovascular mortality. Intense endurance exercise causes mild epithelial injury and inflammation in the airways, but does not appear to exert detrimental effects on respiratory health or bronchial reactivity in recreational/non-elite athletes. Conversely, elite athletes of both summer and winter sports show increased susceptibility to development of asthma, possibly related to environmental exposures to allergens or poor conditioning of inspired air, so that a distinct phenotype of “sports asthma” has been proposed to characterise such athletes, who more often practise aquatic and winter sports. Overall, endurance training is good for health but may become deleterious when performed at high intensity or volume.

Endurance training is good for health but may become deleterious when performed at high intensity or volumehttp://ow.ly/4n9jR4

Childhood asthma and physical activity: a systematic review with meta-analysis and Graphic Appraisal Tool for Epidemiology assessment

BACKGROUND

Childhood asthma is a global problem affecting the respiratory health of children. Physical activity (PA) plays a role in the relationship between asthma and respiratory health. We hypothesized that a low level of PA would be associated with asthma in children and adolescents. The objectives of our study were to (1) summarize the evidence available on associations between PA and asthma prevalence in children and adolescents and (2) assess the role of PA in new-onset or incident asthma among children and adolescents.

METHODS

We searched Medline, the Cochrane Library, and Embase and extracted data from original articles that met the inclusion criteria. Summary odds ratios (ORs) and confidence intervals (CIs) were used to express the results of the meta-analysis (forest plot). We explored heterogeneity using funnel plots and the Graphic Appraisal Tool for Epidemiology (GATE).

RESULTS

We retrieved 1,571 titles and selected 11 articles describing three cohort and eight cross-sectional studies for inclusion. A meta-analysis of the cohort studies revealed a risk of new-onset asthma in children with low PA (OR [95 % CI] 1.32 [0.95; 1.84] [random effects] and 1.35 [1.13; 1.62] [fixed effects]). Three cross-sectional studies identified significant positive associations between childhood asthma or asthma symptoms and low PA.

CONCLUSIONS

Children and adolescents with low PA levels had an increased risk of new-onset asthma, and some had a higher risk of current asthma/or wheezing; however, there was some heterogeneity among the studies. This review reveals a critical need for future longitudinal assessments of low PA, its mechanisms, and its implications for incident asthma in children. The systematic review was prospectively registered at PROSPERO (registration number: CRD42014013761; available at: http://www.crd.york.ac.uk/PROSPERO [accessed: 24 March 2016]).

School environmental factors are predictive for exercise-induced symptoms in children

BACKGROUND

Environmental factors in schools have a significant effect on the exercise-induced bronchoconstriction and symptoms in a general paediatric population.

OBJECTIVES

To determine the environmental factors such as atmospheric conditions and the presence of allergens in gymnasiums, that could be predictive of the presence of exercise-induced symptoms/bronchospasm in children during physical education (PE).

METHODS

1370 schoolchildren were enrolled. Children attended 45 min PE lesson with similar exercise intensity. Pulmonary function tests were performed before and after PE lesson. Air temperature, humidity and pressure, samples of dust for allergen exposure in the gymnasiums were taken. Children who reported symptoms induced during PE lesson were invited to the clinic for ETC (exercise treadmill challenge) and atopy measurement.

RESULTS

1033 participants were included into the analysis. Sixty seven(6.5%) children reported dyspnea/cough, and in 94(9.4%) children bronchoconstriction induced during PE lesson was documented. There is a correlation between the results of the ETC and bronchoconstriction after PE (OR: 2.55; 95%CI: 1.07-6.05; p = 0.034). Exposure to higher air pressure and higher humidity independently increase the risk of clinical symptoms reported during or after PE lesson. Exposure to cat's allergens increase the risk of bronchoconstriction (independently from atopy status). We showed significant interaction between presence of asthma and current ICS therapy as a risk of physical inactivity at school (OR: 4; 95%CI: 1.3-12; p < 0.001).

CONCLUSION

This study showed an effect of cat allergen and environmental factors (humidity, air pressure) on the appearance of exercise related cough/bronchoconstriction during activity class in a natural environment at school in a large urban population of schoolchildren.

Long-term physical activity is associated with reduced arterial stiffness in older adults: longitudinal results of the SAPALDIA cohort study

BACKGROUND

longitudinal analyses of physical activity (PA) and arterial stiffness in populations of older adults are scarce. We examined associations between long-term change of PA and arterial stiffness in the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA).

METHODS

we assessed PA in SAPALDIA 2 (2001-03) and SAPALDIA 3 (2010-11) using a short questionnaire with a cut-off of at least 150 min of moderate-to-vigorous PA per week for sufficient activity. Arterial stiffness was measured oscillometrically by means of the brachial-ankle pulse wave velocity (baPWV) in SAPALDIA 3. We used multivariable mixed linear regression models adjusted for several potential confounders in 2,605 persons aged 50-81.

RESULTS

adjusted means of baPWV were significantly lower in persons with sufficient moderate-to-vigorous PA (i) in SAPALDIA 2 but not in SAPALDIA 3 (P = 0.048) and (ii) in both surveys (P = 0.001) compared with persons with insufficient activity in both surveys. There was a significant interaction between sex and the level of change in PA concerning baPWV (P = 0.03). The triples of parameter estimates describing the association between level of PA change and baPWV were not significantly different between the two sex-specific models (P = 0.07).

CONCLUSIONS

keeping up or adopting a physically active lifestyle was associated with lower arterial stiffness in older adults after a follow-up of almost a decade. Increasing the proportion of older adults adhering to PA recommendations incorporating also vigorous PA may have a considerable impact on vascular health at older age and may contribute to healthy ageing in general.

Advances in asthma pathophysiology: stepping forward from the Maurizio Vignola experience

Maurizio Vignola was a superb and innovative researcher, who wrote seminal papers on the biology of airway epithelium in asthma. Inflammation and remodelling were the main topics of his research, mostly conducted in biopsy specimens from patients with asthma of variable severity, encompassing the entire spectrum of the disease from mild to severe asthma. His observations contributed to define the biology of asthma as we know it today, and opened the way to the personalised treatment of asthma. His group has successfully continued to investigate the biology and clinical aspects of bronchial asthma, with major interest in the clinical use of biomarkers to monitor disease activity, and in the development of new therapeutic perspectives. This review summarises the latest work on these topics proudly conducted by Maurizio's closest collaborators. The results indicate significant progress in our understanding of asthma in the last 10 years, in particular increased knowledge of the complex interaction between inflammatory and remodelling pathways, improved recognition of biological and clinical asthma phenotypes, and development of new treatment strategies, especially for patients with severe corticosteroid-resistant asthma.

Biomarkers may help to define disease phenotypes and new treatment strategies for asthmahttp://ow.ly/G2Fl6

Impact of varying physical activity levels on airway sensitivity and bronchodilation in healthy humans

The purpose of this study was to determine if the amount of physical activity influences airway sensitivity and bronchodilation in healthy subjects across a range of physical activity levels. Thirty healthy subjects (age, 21.9 ± 2.6 years; 13 men/17 women) with normal pulmonary function reported to the laboratory on 2 separate occasions where they were randomized to breathe either hypertonic saline (HS) (nebulized hypertonic saline (25%) for 20 min) or HS followed by 5 deep inspirations (DIs), which has been reported to bronchodilate the airways. Pulmonary function tests (PFTs) were performed prior to both conditions and following the HS breathing or 5 DIs. Moderate to vigorous physical activity (MVPA) level was measured via accelerometer worn for 7 days. Following the HS breathing, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) significantly decreased from baseline by –11.8% ± 8.4% and –9.3% ± 6.7%, respectively. A 2-segment linear model determined significant relationships between MVPA and percent change in FEV1 (r = 0.50) and FVC (r = 0.55). MVPA above ∼497 and ∼500 min/week for FEV1 and FVC, respectively, resulted in minor additional improvements (p > 0.05) in PFTs following the HS breathing. Following the DIs, FEV1 and FVC decreased (p < 0.05) by –7.3% ± 8.6% and –5.7% ± 5.7%, respectively, from baseline, but were not related (p > 0.05) to MVPA. In conclusion, these data demonstrate that higher MVPA levels attenuated airway sensitivity but not bronchodilation in healthy subjects.

High levels of physical activity are associated with poorer asthma control in young females but not in males

BACKGROUND AND OBJECTIVE

Earlier studies on the levels of physical activity in asthma patients compared with controls have yielded varying results. We have previously reported that high versus moderate levels of physical activity were associated with higher prevalence of wheezing, especially in females. Here we studied the levels of physical activity in young patients with asthma and healthy subjects and their effect on asthma control.

METHODS

Four hundred eight physician-diagnosed patients with asthma and 118 controls (10-34 years) answered questions concerning frequency and/or duration of physical activity and undertook the Asthma Control Test (ACT), spirometry, methacholine challenges and exhaled nitric oxide measurements.

RESULTS

Asthma patients were more frequently physically active (P = 0.01) and for longer durations (P = 0.002) than controls. Highly versus moderately physically active patients with asthma had a higher prevalence of not well-controlled asthma (ACT < 20) when physical activity was assessed by frequency (40.6% vs 24.1%, P = 0.001) or duration (39.0% vs 21.7%, P < 0.001). This was only seen in females who had reduced ACT items (P < 0.05). Frequently versus moderately active females had an odds ratio of 4.81 (2.43, 9.51) to have ACT < 20, while no such effect was found in males (OR 1.18 (0.61, 2.30)) and this interaction was statistically significantly associated with gender (P = 0.003). No differences in fraction of exhaled nitric oxide or methacholine reactivity were found between moderately and highly physically active females with asthma.

CONCLUSION

Young asthma patients were more active than controls. High levels of physical activity were associated with poor asthma control as judged by the ACT in females, but not in males, and this appears unrelated to airway inflammation or responsiveness.

The allergy epidemics: 1870-2010

Before the first description of hay fever in 1870, there was very little awareness of allergic disease, which is actually similar to the situation in prehygiene villages in Africa today. The best explanation for the appearance and subsequent increase in hay fever at that time is the combination of hygiene and increased pollen secondary to changes in agriculture. However, it is important to remember that the major changes in hygiene in Northern Europe and the United States were complete by 1920. Asthma in children did not start to increase until 1960, but by 1990, it had clearly increased to epidemic numbers in all countries where children had adopted an indoor lifestyle. There are many features of the move indoors that could have played a role; these include increased sensitization to indoor allergens, diet, and decreased physical activity, as well as the effects of prolonged periods of shallow breathing. Since 1990, there has been a remarkable increase in food allergy, which has now reached epidemic numbers. Peanut has played a major role in the food epidemic, and there is increasing evidence that sensitization to peanut can occur through the skin. This suggests the possibility that changes in lifestyle in the last 20 years could have influenced the permeability of the skin. Overall, the important conclusion is that sequential changes in lifestyle have led to increases in different forms of allergic disease. Equally, it is clear that the consequences of hygiene, indoor entertainment, and changes in diet or physical activity have never been predicted.

Effects of weight loss on airway responsiveness in obese adults with asthma: does weight loss lead to reversibility of asthma?

BACKGROUND

The growing epidemics of obesity and asthma are major public health concerns. Although asthma-obesity links are widely studied, the effects of weight loss on asthma severity measured by airway hyperresponsiveness (AHR) have received limited attention. The main study objective was to examine whether weight reduction reduces asthma severity in obese adults with asthma.

METHODS

In a prospective, controlled, parallel-group study, we followed 22 obese participants with asthma aged 18 to 75 years with a BMI ≥ 32.5 kg/m2 and AHR (provocative concentration of methacholine causing a 20% fall in FEV1 [PC20] < 16 mg/mL). Sixteen participants followed a behavioral weight reduction program for 3 months, and six served as control subjects. The primary outcome was change in AHR over 3 months. Changes in lung function, asthma control, and quality of life were secondary outcomes.

RESULTS

At study entry, participant mean ± SD age was 44 ± 9 years, 95% were women, and mean BMI was 45.7 ± 9.2 kg/m2. After 3 months, mean weight loss was 16.5 ± 9.9 kg in the intervention group, and the control group had a mean weight gain of 0.6 ± 2.6 kg. There were significant improvements in PC20 (P = .009), FEV1 (P = .009), FVC (P = .010), asthma control (P < .001), and asthma quality of life (P = .003) in the intervention group, but these parameters remained unchanged in the control group. Physical activity levels also increased significantly in the intervention group but not in the control group.

CONCLUSIONS

Weight loss in obese adults with asthma can improve asthma severity, AHR, asthma control, lung function, and quality of life. These findings support the need to actively pursue healthy weight-loss measures in this population.

Alterations in Lung Functions Based on BMI and Body Fat % Among Obese Indian Population at National Capital Region

BACKGROUND

In India, non-asthmatic hospital admission case study has been conducted to find out the relationship between obesity and lung functions. The main objective of the present study was to find out the alterations in lung functions due to obesity among Indian population living at National Capital Region (NCR).

MATERIALS AND METHODS

We examined 609 non obese and 211 obese subjects in a cross sectional study from National Capital Region, India with age group ranges between 18-70 years. BMI and body fat % was determined using body fat analyzer. Obese and non-obese subjects were classified based on criteria for BMI and Body fat %. Lung function test viz., FEV1 and PEFR were conducted using portable spirometer (PIKO-1).

RESULTS

A significant correlation (p<0.05) was observed between BMI and PEFR among non-obese male and female subjects. Decline in PEFR and FEV1 values for corresponding increase in body fat % was observed among study subjects. A significant (p<0.01) decline in mean FEV1 and PEFR was observed among non-obese and obese subjects, compared to their Indian reference standards for lung functions. A significant negative correlation (p<0.01) was observed between body fat % and lung functions (FEV1, PEFR).

CONCLUSION

It is concluded that obese subjects are at a risk of lung function impairment, based on the criteria followed for BMI and body fat %. The study also demonstrate that body fat% classification as a better index for determination of obese subjects compared to BMI classification, with respect to lung function impairments.

Comparative Study of Bronchial Hyperresponsiveness Between Football and Judo Groups in Prepubertal Boys

BACKGROUND

Exercise induced bronchospasm (EIB) commonly occurs during exercise. The comparative effects of different sports on airway responsiveness among prepubertal boys remain to be determined.

OBJECTIVES

To assess differences in post exercise spirometry between footballers, judokas and a control group in prepubertal boys.

PATIENTS AND METHODS

A total of ninety six prepubertal boys were studied. Bronchial hyper responsiveness (BHR) to exercise challenge test was defined by a diagnosis of baseline spirometry, followed by an incremental exercise test. To date, the best test to confirm EIB may simply be standard pulmonary function testing before and after high-intensity exercise. A 10% or greater post-challenge fall in forced expiratory volume in FEV1 is used as a diagnostic criterion.

RESULTS

There was no significant difference in baseline spirometry between all groups (P > 0.05). The post exercise spirometry test revealed the presence of EIB in 16 of 32 (50%) footballers against 9 out of 32 (28.12%) in both judokas and control subjects at 5 min after the exercise. Also, there was a significantly higher decrease (P < 0.05) in mean FEV1 at 5 minuts in footballers (-9.60 ± 6.18) compared to judokas (-5.41 ± 5.85).

CONCLUSIONS

The footballers have more BHR than judokas, especially at 5min after the exercise. This may be due to prolonged hyperventilation, atopy and increased exposure to inhaled allergens and pollutants during training and competition.

Asthma prevalence in Olympic summer athletes and the general population: An analysis of three European countries

BACKGROUND

Some studies have shown a higher prevalence of asthma in elite athletes as compared to the general population. It is inconclusive to what extent certain sport categories are especially affected. The present study offered a unique opportunity to assess these differences in asthma prevalence in the general population and elite summer athletes from a wide range of sport disciplines across various geographical areas.

METHODS

Cross-sectional data for 1568 general population participants from the European Community Respiratory Health Survey II and 546 elite athletes from the Global Allergy and Asthma European Network Olympic study from three European countries were analyzed. Using logistic regression, the asthma risks associated with athlete sport practice, endurance level and aquatic sport practice, respectively, were investigated.

RESULTS

Athletes in the highest endurance category had increased risk of doctor-diagnosed asthma (OR 3.5; 95% CI 1.7-7.5), asthma symptoms (OR 3.0; CI 1.5-6.0) and asthma symptoms or medication use (OR 3.5; CI 1.8-6.7) compared to the general population. Aquatic athletes were at increased risk of doctor-diagnosed asthma (OR 2.0; CI 1.1-3.9), asthma symptoms (OR 2.6; CI 1.3-5.0) and asthma symptoms or medication use (OR 2.3; CI 1.2-4.4) when compared to individuals not involved in aquatic sports. Regarding the entire athlete population, no increase in asthma was found when compared to the general population.

CONCLUSIONS

Practice of very high endurance and aquatic sports may be associated with increased asthma risks. Athlete participation as such showed no association with asthma risk.

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

BACKGROUND

Although exercise has multiple health benefits, relatively little attention has been paid to its potential therapeutic effects in those with asthma.

OBJECTIVE

To examine the effects of acute exercise on inflammation in physically inactive and active adults with asthma.

METHODS

Fourteen adults with asthma (n = 6 physically inactive, n = 8 physically active) completed (1) 30 minutes of moderate-intensity exercise on a treadmill and (2) 30 minutes of rest in random order, with 4 weeks between sessions. Exhaled nitric oxide (eNO) was measured before and after the intervention (0, 0.5, 1, 2, 4, and 24 hours). Blood inflammatory mediators were measured before and after the intervention (0, 2, and 24 hours).

RESULTS

Physically inactive participants had a significant decrease in eNO 4 hours after exercise (-4.8 ppb, -6.4 to -0.5 ppb, P = .028), which was not observed in physically active participants (P = .362). Interluekin-1 receptor antagonist increased in the physically inactive group 2 hours after exercise, with this increase strongly correlated with the decrease in eNO at 4 hours (R = -0.685, P = .007) and 24 hours (R = -0.659, P = .014) after exercise. Interleukin-6 was increased significantly 2 hours after exercise in physically inactive participants. Blood neutrophils and nuclear factor erythroid 2-like 2 gene expression were increased 2 hours after exercise in the overall cohort.

CONCLUSION

This study demonstrates that acute moderate-intensity exercise is associated with decreased eNO in physically inactive adults with asthma and suggests that interluekin-1 receptor antagonist could have a role in mediating this effect. The attenuated response in physically active participants might be due to the sustained anti-inflammatory effects of exercise training. Future studies should investigate the impact of exercise intensity and exercise training on airway inflammation in those with asthma.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au), registration number ACTRN12613001014741.

Physical activity and respiratory symptoms in children: the Generation R Study

BACKGROUND

To assess the relationship between physical activity in second year of life and respiratory symptoms during the pre-school period.

METHODS

This study was embedded in the Generation R Study, a large prospective birth-cohort study in Rotterdam, the Netherlands. Physical activity was measured in the second year of life by an Actigraph accelerometer in a subgroup of 347 children (182 boys, 165 girls; mean age 25.1 months) and data were expressed as counts per 15 sec in categories: light activity (302-614 counts/15 sec), moderate activity (615-1,230 counts/15 sec), and vigorous activity (≥1,231 counts/15 sec). Respiratory symptoms were assessed by the International Study of Asthma and Allergies in Childhood Questionnaire in the third and fourth year of life.

RESULTS

Physical activity levels were not associated with wheezing symptoms in the third and fourth year of life (OR: 0.98; 95% CI: 0.92-1.05 and OR: 0.99; 95% CI: 0.92-1.07 for total activity, respectively), nor associated with shortness of breath symptoms (OR: 0.98; 95% CI: 0.92-1.05 and OR 1.03; 95% CI: 0.96-1.11 for total activity, respectively).

CONCLUSION

These results suggest that physical activity may not play an important role in the development of respiratory symptoms in pre-school children.

Is a cutoff of 10% appropriate for the change-in-estimate criterion of confounder identification?

Background

When using the change-in-estimate criterion, a cutoff of 10% is commonly used to identify confounders. However, the appropriateness of this cutoff has never been evaluated. This study investigated cutoffs required under different conditions.

Methods

Four simulations were performed to select cutoffs that achieved a significance level of 5% and a power of 80%, using linear regression and logistic regression. A total of 10 000 simulations were run to obtain the percentage differences of the 4 fitted regression coefficients (with and without adjustment).

Results

In linear regression, larger effect size, larger sample size, and lower standard deviation of the error term led to a lower cutoff point at a 5% significance level. In contrast, larger effect size and a lower exposure–confounder correlation led to a lower cutoff point at 80% power. In logistic regression, a lower odds ratio and larger sample size led to a lower cutoff point at a 5% significance level, while a lower odds ratio, larger sample size, and lower exposure–confounder correlation yielded a lower cutoff point at 80% power.

Conclusions

Cutoff points for the change-in-estimate criterion varied according to the effect size of the exposure–outcome relationship, sample size, standard deviation of the regression error, and exposure–confounder correlation.

Ventilation and respiratory mechanics

During dynamic exercise, the healthy pulmonary system faces several major challenges, including decreases in mixed venous oxygen content and increases in mixed venous carbon dioxide. As such, the ventilatory demand is increased, while the rising cardiac output means that blood will have considerably less time in the pulmonary capillaries to accomplish gas exchange. Blood gas homeostasis must be accomplished by precise regulation of alveolar ventilation via medullary neural networks and sensory reflex mechanisms. It is equally important that cardiovascular and pulmonary system responses to exercise be precisely matched to the increase in metabolic requirements, and that the substantial gas transport needs of both respiratory and locomotor muscles be considered. Our article addresses each of these topics with emphasis on the healthy, young adult exercising in normoxia. We review recent evidence concerning how exercise hyperpnea influences sympathetic vasoconstrictor outflow and the effect this might have on the ability to perform muscular work. We also review sex-based differences in lung mechanics.

Asthma and physical activity--a population based study results from the Swedish GA(2)LEN survey

BACKGROUND

Having asthma has in previous reports been related to a lower physical activity level. At the same time the prevalence of asthma among elite athletes is high. The aim of this study was to investigate the association between physical activity level and asthma.

METHODS

A postal questionnaire was completed by 25,610 individuals in Sweden. Current asthma was defined as having had an asthma attack during the last 12 months or current use of asthma medication. The participants were asked how often and for how many hours a week they were physically active.

RESULTS

In the population 1830 subjects (7.1%) had current asthma. There was no significant difference in the proportion of subjects that reported being inactive or slightly physically active between asthmatic and non-asthmatics (57 vs. 58%) while the proportion of subjects that were vigorously physically active (≥2 times a week and ≥7 h per week) was higher among the subjects with asthma (6.7 vs. 4.8%, p < 0.0001). Being vigorously physically active was independently related to current asthma (OR (95% CI)) 1.40 (1.11-1.77)), wheeze (1.39 (1.17-1.65)), wheeze and breathlessness (1.68 (1.38-2.04)), and wheezing without having a cold (1.39 (1.13-1.71)). The association between being vigorously physically active and wheeze was significantly stronger in women compared to men.

CONCLUSIONS

There was no difference in the proportion of subjects with a reported low level of physical activity between asthmatics and non-asthmatics. Health care professionals should, however, be aware of the increased prevalence of asthma and asthma-related symptoms in vigorously physically active subjects.

Impact of weight loss on markers of systemic inflammation in obese Saudi children with asthma

BACKGROUND

Weight loss studies were conducted in children without asthma have demonstrated a reduction in systemic inflammation. However, the impact of weight loss in the obese paediatric population with asthma has not been investigated.

OBJECTIVE

To measure the effects of weight loss on markers of systemic inflammation in obese children with bronchial asthma.

METHODS

Eighty obese children with bronchial asthma (42 boys, and 38 girls) with mean age 13.86 ± 3.21 years were divided into two equal groups. The training group received diet regimen, exercise training in addition to the medical treatment for two months, where the control group received the medical treatment only.

RESULTS

There was a 17.5%, 15.5%, 22.4%, 14.1% and 15.9% reduction in mean values of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), Leptin and body mass index (BMI) respectively and 38.7 % increase in mean values of adiponectin in the training group. While, there was a 0.7%, 9.0%, 2.8%, 1.6% and 1.2% increase in mean values of TNF-alpha, IL-6, IL-8, Leptin and BMI respectively and 3.9% decrease in mean values of adiponectin in the control group. The mean values of TNF-alpha, IL-6, IL-8, Leptin and BMI was decreased and adiponectin was increased significantly in the training group, however the results of the control group were not significant. Also, there were significant differences between both groups at the end of the study.

CONCLUSION

Weight loss improves markers of systemic inflammation in obese Saudi children with bronchial asthma.

Obesity and asthma: physiological perspective

Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC). Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma.

Exercise training attenuated chronic cigarette smoking-induced up-regulation of FIZZ1/RELMα in lung of rats

FIZZ/RELM is a new gene family named "found in inflammatory zone" (FIZZ) or "resistin-like molecule" (RELM). FIZZ1/RELMα is specifically expressed in lung tissue and associated with pulmonary inflammation. Chronic cigarette smoking up-regulates FIZZ1/RELMα expression in rat lung tissues, the mechanism of which is related to cigarette smoking-induced airway hyperresponsiveness. To investigate the effect of exercise training on chronic cigarette smoking-induced airway hyperresponsiveness and up-regulation of FIZZ1/RELMα, rat chronic cigarette smoking model was established. The rats were treated with regular exercise training and their airway responsiveness was measured. Hematoxylin and eosin (HE) staining, immunohistochemistry and in situ hybridization of lung tissues were performed to detect the expression of FIZZ1/RELMα. Results revealed that proper exercise training decreased airway hyperresponsiveness and pulmonary inflammation in rat chronic cigarette smoking model. Cigarette smoking increased the mRNA and protein levels of FIZZ1/RELMα, which were reversed by the proper exercise. It is concluded that proper exercise training prevents up-regulation of FIZZ1/RELMα induced by cigarette smoking, which may be involved in the mechanism of proper exercise training modulating airway hyperresponsiveness.

Physical activity and exercise-induced bronchoconstriction in Greek schoolchildren

OBJECTIVE

To investigate the association between physical activity and exercise-induced bronchoconstriction (EIB) in an urban population sample of schoolchildren, taking into account potential confounders such as asthma symptoms and overweight.

METHODS

Children aged 10-12 years answered validated questionnaires on physical activity (Physical Activity and Lifestyle Questionnaire) and asthma symptoms (ISAAC questionnaire), and were categorized according to their body mass index (BMI). EIB (FEV(1) decrease from baseline ≥13%) was assessed by a standardized free running Exercise Challenge Test (ECT).

RESULTS

Six hundred seven children completed the ECT. There were no differences among asthma groups (diagnosed asthma, asthma-related symptoms not diagnosed as asthma, no asthma-related symptoms) regarding total daily energy expenditure and time spent in mild (1.1-2.9 metabolic equivalents-METs), moderate (3-6 METs), and vigorous (>6 METs) activities. Only overweight/obese EIB-positive children had shorter duration of vigorous activity as compared to their EIB-negative or non-overweight/obese EIB-positive peers. Total daily energy expenditure and duration of mild- and moderate-intensity activity were negatively associated with EIB independently of BMI status or asthma-related symptoms.

CONCLUSIONS

Decreased levels of physical activity are associated with EIB irrespectively of BMI status and asthma-related symptoms. Longitudinal studies are needed to confirm the negative impact of sedentary lifestyle on the development of EIB suggested by these findings.

Effects of exercise training on airway closure in asthmatics

We previously reported that responsiveness to methacholine (Mch) in the absence of deep inspiration (DI) decreased in healthy subjects after a short course of exercise training. We assessed whether a similar beneficial effect of exercise on airway responsiveness could occur in asthmatics. Nine patients (male/female: 3/6; mean age ± SD: 24 ± 2 yr) with mild untreated asthma [forced expiratory volume in 1 s (FEV(1)): 100 ± 7.4% pred; FEV(1)/vital capacity (VC): 90 ± 6.5%] underwent a series of single-dose Mch bronchoprovocations in the absence of DI in the course of a 10-wk training rowing program (6 h/wk of submaximal and maximal exercise), at baseline (week 0), and at week 5 and 10. The single-dose Mch was established as the dose able to induce ≥ 15% reduction in inspiratory vital capacity (IVC) and was administered to each subject at every challenge occasion. Five asthmatics (male/female: 1/4; mean age ± SD: 26 ± 3 yr) with similar baseline lung function (FEV(1): 102 ± 7.0% predicted; FEV(1)/VC: 83 ± 6.0%; P = 0.57 and P = 0.06, respectively) not participating in the exercise training program served as controls. In the trained group, the Mch-induced reduction in IVC from baseline was 22 ± 10% at week 0, 13 ± 11% at week 5 (P = 0.03), and 11 ± 8% at week 10 (P = 0.028). The Mch-induced reduction in FEV(1) did not change with exercise (P = 0.69). The reduction in responsiveness induced by exercise was of the same magnitude of that previously obtained in healthy subjects (50% with respect to pretraining). Conversely, Mch-induced reduction in IVC in controls remained unchanged after 10 wk (%reduction IVC at baseline: 21 ± 20%; after 10 wk: 29 ± 14%; P = 0.28). This study indicates that a short course of physical training is capable of reducing airway responsiveness in mild asthmatics.

High-intensity training improves airway responsiveness in inactive nonasthmatic children: evidence from a randomized controlled trial

PURPOSE

the relationship between physical activity and airway health in children is not well understood. The purpose of this study was to determine whether 8 wk of high-intensity exercise training would improve airway responsiveness in prepubescent, nonasthmatic, inactive children.

METHODS

16 healthy, prepubescent children were randomized [training group (TrG) n = 8, control group (ConG) n = 8]. Prior to and following 8 wk of training (or no training), children completed pulmonary function tests (PFTs): forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), forced expiratory flow at 25-75% of vital capacity (FEF(25-75)), and exhaled nitric oxide (FENO). Children completed an incremental cycle Vo(2max) test, eucapnic voluntary hyperventilation (EVH), anthropometric tests, and blood tests to determine fasting blood glucose, total cholesterol, HDL, LDL, and triglycerides. Body fat percentage was determined using dual-energy X-ray absorptiometry pretraining and bioelectrical impedance pre- and posttraining.

RESULTS

there were no differences (P > 0.05) in anthropometric measures or PFTs between TrG and ConG at baseline. In the TrG, there was a significant increase in Vo(2max) (∼24%) and a decrease in total cholesterol (∼13%) and LDL cholesterol (∼35%) following training. There were improvements (P < 0.05) in ΔFEV(1) both postexercise (pre: -7.60 ± 2.10%, post: -1.10 ± 1.80%) and post-EVH (pre: -6.71 ± 2.21%, post: -1.41 ± 1.58%) with training. The ΔFEF(25-75) pre-post exercise also improved with training (pre: -16.10 ± 2.10%, post: -6.80 ± 1.80%; P < 0.05). Lower baseline body fat percentages were associated with greater improvements in pre-post exercise ΔFEV(1) following training (r = -0.80, P < 0.05).

CONCLUSION

these results suggest that in nonasthmatic prepubescent children, inactivity negatively impacts airway responsiveness, which can be improved with high-intensity training. Excess adiposity, however, may constrain these improvements.

Cromoglycate, reproterol, or both--what's best for exercise-induced asthma?

OBJECTIVE

International guidelines recommend short- (SABA) or long-acting b-agonists for the prevention of bronchoconstriction after exercise (EIB) in patients with exercise-induced asthma (EIA). However, other drugs are still in discussion for the prevention of EIB. We investigated the efficacy of a combination of inhaled sodium cromoglycate and the β-mimetic drug reproterol versus inhaled reproterol alone and both versus inhaled placebo in subjects with exercise-induced asthma (EIA).

METHODS

The study aimed to prove the preventive effect of a combination of 1-mg reproterol and 2-mg disodium cromoglycate (DSCG) and its single components vs. placebo, measuring the decrease of FEV1 after a standardized treadmill test in 11 patients with recorded EIA. The study medication was twice as high as those of drugs which are commercially available (e.g., Allergospasmin®, Aarane®).

RESULTS

The results revealed that the combination of reproterol and DSCG was significantly effective against a decrease of FEV1 after a standardized exercise challenge test (ECT) compared to placebo. The short-acting b-agonist reproterol alone had almost the same effectiveness as the combination of reproterol and DNCG. The difference between the combination with DNCG and reproterol alone was less than 10% and insignificant (p 0.48). DNCG alone did not show a difference in the effectiveness compared to placebo.

CONCLUSION

Prevention of EIA with the combination of reproterol and DSCG or with reproterol only is effective. An exclusive recommendation in favor of the combination cannot be given due to the low difference in the effectiveness versus reproterol alone. Due to the limited number of subjects and some probands showing protection under DSCG, it cannot be completely excluded that there is some preventive power of DSCG in individual cases.

Airway responsiveness measured by forced oscillation technique in severely obese patients, before and after bariatric surgery

BACKGROUND

The influence of obesity on airway responsiveness remains controversial.

OBJECTIVE

This study was designed to investigate airway responsiveness, airway inflammation, and the influence of sleep apnea syndrome (SAS), in severely obese subjects, before and after bariatric surgery.

METHODS

A total of 120 non-asthmatic obese patients were referred consecutively for pre-bariatric surgery evaluation. Lung function, airway responsiveness to methacholine, exhaled nitric oxide measurement, and sleep studies were performed. Airway hyperresponsiveness (AHR) was defined as a 50% or greater increase in respiratory resistance measured using the forced oscillation technique in response to a methacholine dose ≤ 2000 μg. Forced expiratory volume in 1 second (FEV₁) was measured after the last methacholine dose. Airway responsiveness was reevaluated after weight loss in patients with a pre-surgery AHR.

RESULTS

AHR was found in 16 patients. The percent FEV₁ decrease or percent respiratory resistance increase in response to methacholine was related to baseline expiratory airflow (forced expiratory flow at 50%) (r = 0.26, p < .006 and r = 0.315, p = .0005, respectively) but not to body mass index (BMI) or exhaled nitric oxide. Both airway responsiveness parameters were significantly related to forced expiratory flow at 25-75%/forced vital capacity, a measure of airway size relative to lung size (r = 0.27, p < .005 and r = 0.25, p < .007, respectively). Sleep apnea was not significantly associated with AHR or airway inflammation. About 11 patients with AHR were reevaluated 18 months to 2 years after surgery, with no change in AHR associated with weight loss.

CONCLUSION

Airway responsiveness is not related to BMI or to SAS. AHR in severely obese patients might be related to distal airway obstruction or low relative airway size.

Swimming and asthma: factors underlying respiratory symptoms in competitive swimmers

BACKGROUND

Swimming is recommended for asthmatics. However, many competitive swimmers report asthmatic symptoms. While some studies identify the swimming environment as a trigger for allergy and asthmatic symptoms, even more studies suggest swimming to be suitable for people with allergies and asthma. The factors behind the symptoms were studied first by determining the prevalence of asthma, allergy and self-reported asthmatic symptoms in experienced Finnish swimmers and then by examining the relationships between the reported symptoms and the main triggering factors: medical history, environment and exercise intensity.

MATERIALS AND METHODS

Top swimmers (n = 332) of the Finnish Swimming Association registry (N = 4578) were asked to complete a structured questionnaire on their medical history, swimming background, swimming environment and symptoms in different swimming intensities. Two hundred experienced swimmers, 107 females and 93 males, with an average age of 18.5 [standard deviation (SD) = 3.0] years and a swimming training history of 9 (SD = 3.8) years completed the questionnaire.

RESULTS

Physician-diagnosed asthma was reported by 32 swimmers (16%), including 24 (12%) with exercise-induced asthma. Physician-diagnosed allergy was reported by 81 (41%) swimmers. Asthmatic symptoms during swimming were described by 84 subjects (42%). Most symptoms occurred when swimming exceeded speeds corresponding to the lactic/anaerobic threshold. Family history of asthma was significant and the most important risk factor for asthmatic symptoms.

CONCLUSIONS

The prevalence of asthma in swimmers was higher than in the general population but not different from that in other endurance athletes. Family history of asthma and increased swimming intensity had the strongest associations with the reported asthmatic symptoms.

What can we learn about asthma and allergy from the follow-up of the RHINE and the ECRHS studies?

OBJECT

The international population-based studies RHINE and ECRHS have provided new insight in the epidemiology and management of asthma, allergy and rhinitis in young adults. The aim of the present review is to focus on longitudinal results with regard incidence and net change of asthma and asthma-like symptoms, risk factors and management of asthma, with special reference to the Nordic-Baltic countries.

RESULTS

Asthma and rhinitis are common conditions that are important in a public health perspective. There are gender differences in incidence and remission. A socio-economic gradient that non-atopic asthma is more strongly related to poverty seems to have developed in the last decade. These findings will challenge our welfare states in the future. In addition, occupational, as well as indoor and outdoor environmental exposures, influenced the onset of asthma. The population-attributable risk for adult asthma because of occupational exposures is equivalent to an incidence of new-onset asthma of 250-300 cases per million per year. Genetic factors, allergic sensitisation, gastro-oesophageal reflux, habitual snoring, diet and other factors may also contribute to the onset of asthma and rhinitis. Even though management of asthma has improved, there are still great variations throughout Europe. These findings highlight the key role doctors and nurses play in educating and reviewing management of patients.

Hormonal factors and respiratory health in women--a review

Sex hormones appear to play an important role in the lung health of women. This is, however, poorly understood and, in most aspects, poorly investigated; and the literature has been contradictory and confusing. This review presents recent research concerning the involvement of sex hormones in respiratory health of adult women, using the population surveys European Community Respiratory Health Survey and Respiratory Health in Northern Europe. Respiratory health varied substantially according to hormonal and metabolic conditions. First, menopause was associated with lower lung function and more respiratory symptoms, especially among lean women. Second, hormonal replacement therapy (HRT) was associated with increased risk for asthma and wheeze; also, this association was particularly strong among lean women. Third, women with irregular menstruations in fertile age had more asthma, particularly allergic asthma, and reduced lung function, independently of body mass index (BMI) and physical activity. The findings were consistent across cultural and geographical borders. Our studies revealed that considering interplay between hormonal and metabolic factors is a clue to understand the effects of female sex hormones on the airways. A BMI of around 24-25 kg/m(2) appeared to be optimal; women with this BMI had no increase in respiratory health problems when reaching menopause or using HRT, and women in fertile age with this BMI had optimal lung function independently of menstrual status. In conclusion, female sex hormones appear to play a most important role for lung health in women. Further research on effects of sex hormones on the airways should take into account potential interplay with metabolic factors.

Effects of exercise training on airway responsiveness and airway cells in healthy subjects

Airway responsiveness to methacholine (Mch) in the absence of deep inspirations (DIs) is lower in athletes compared with sedentary individuals. In this prospective study, we tested the hypothesis that a training exercise program reduces the bronchoconstrictive effect of Mch. Ten healthy sedentary subjects (M/F: 3/7; mean + or - SD age: 22 + or - 3 yr) entered a 10-wk indoor rowing exercise program on rowing ergometer and underwent Mch bronchoprovocation in the absence of DIs at baseline, at weeks 5 and 10, as well as 4-6 wk after the training program was completed. Exercise-induced changes on airway cells and markers of airway inflammation were also assessed by sputum induction and venous blood samples. Mean power output during the 1,000 m test was 169 + or - 49 W/stroke at baseline, 174 + or - 49 W/stroke at 5 wk, and 200 + or - 60 W/stroke at 10 wk of training (P < 0.05). The median Mch dose used at baseline was 50 mg/ml (range 25-75 mg/ml) and remained constant per study design. At the pretraining evaluation, the percent reduction in the primary outcome, the inspiratory vital capacity (IVC) after inhalation of Mch in the absence of DIs was 31 +/- 13%; at week 5, the Mch-induced reduction in IVC was 22 + or - 19%, P = 0.01, and it further decreased to 15 + or - 11% at week 10 (P = 0.0008). The percent fall in IVC 4-6 wk after the end of training was 15 + or - 11% (P = 0.87 vs. end of training). Changes in airway cells were not associated with changes in airway responsiveness. Our data show that a course of exercise training can attenuate airway responsiveness against Mch inhaled in the absence of DIs in healthy subjects and suggest that a sedentary lifestyle may favor development of airways hyperresponsiveness.

Physical activity in young children is reduced with increasing bronchial responsiveness

BACKGROUND

Physical activity is essential for young children to develop adequately and for quality of life. It can be lower in children with subclinical asthma, and therefore methods to reveal subclinical reduction in physical activity in young children are warranted.

OBJECTIVE

We sought to study an association between physical activity in preschool children and objectively assessed intermediary asthma phenotypes.

METHODS

We studied 253 five-year-old children (127 girls) participating in the Copenhagen Prospective Studies on Asthma in Childhood. The main outcome measure was level of physical activity assessed objectively with accelerometers worn on an ankle for 4 weeks. Objective assessment of asthma intermediary phenotypes included prebronchodilator and postbronchodilator specific airway resistance, bronchial responsiveness to cold dry-air hyperventilation, and exhaled nitric oxide levels. Analyses were performed with generalized linear model and principal component analysis.

RESULTS

Physical activity was inversely associated with bronchial responsiveness (relative rate, 0.89; 95% CI, 0.83-0.95; P = .007) and significantly increased in the months of spring and summer (P < .001) and in boys (relative rate, 1.16; 95% CI, 1.09-1.25; P < .001). Physical activity was independent of asthma diagnosis, age, body mass index, baseline specific airway resistance, reversibility to beta(2)-agonist, sensitization, and exhaled nitric oxide level.

CONCLUSION

Physical activity in preschool children was reduced with increasing bronchial responsiveness. The reduced physical activity was subclinical and not realized by parents or doctors despite daily diary cards and close clinical follow-up since birth. This observation warrants awareness of even very mild asthma symptoms in clinical practice.