Non-asthmatic Participants Research Articles

Association Between Serum Level of Interleukin-15 and Severity of Pediatric Asthma

Background: A chronic inflammatory process of the airways is a common characteristic of asthma, representing a primary health problem. This disease can infect people of all ages, about 3.5-20 % of the population, but it usually begins in childhood. Objective: To evaluate the relationship between interleukin-15 and pediatric asthma severity. Methods: The current study is a case-control study that includes 60 asthmatic participants as the patient group and 60 non-asthmatic participants as the control group. Sandwich ELISA using an ELISA kit can be used for the measurement of IL-15 and IgE serum levels. Results: Elevated serum level of IgE in the patients group compared with a control group with significant (P= 0.005) was a result of this study, and there were no significant differences between patients and control about IL- 15 serum levels with (P= 0.968) in asthmatic children. Conclusions: According to the present study, there was a non-significant association between the severity of asthma and the serum level of IL-15 in children.

Gut microbiome signature and nasal lavage inflammatory markers in young people with asthma

BackgroundAsthma is a complex disease and a severe global public health problem resulting from interactions between genetic background and environmental exposures. It has been suggested that the gut microbiota may be related to asthma development, however, such relationships needs further investigation. ObjectiveThis study aimed to characterize the gut microbiota as well as the nasal lavage cytokine profile of asthmatic and non-asthmatic individuals. MethodsStool and nasal lavage samples were collected from 29 children and adolescents with Type 2-asthma (defined as asthma with >2.5% eosinophils in sputum, and a positive skin prick test) and 28 children without asthma in Brazil. Amplicon sequencing of the stool bacterial V4 region of the 16S rRNA gene was performed using Illumina MiSeq. Microbiota analysis was performed using QIIME2 and PICRUST. Type 2-asthma phenotype was characterized by high sputum eosinophil counts and positive skin prick tests for house dust mites, cockroaches, cat or dog dander. The nasal immune marker profile was assessed using a customized multiplex panel. ResultsThe stool microbiota differed significantly between asthmatic and non-asthmatic participants (p=0.001). Bacteroides was more abundant in participants with asthma (p<0.05), while Prevotella was more abundant in non-asthmatics (p<0.05). In asthmatics, the relative abundance of Bacteroides correlated with IL-4 concentration in nasal lavage. Inference of microbiota functional capacity identified differential fatty acid biosynthesis in asthmatics compared to non-asthmatics. ConclusionThe stool microbiota differed between asthmatics and non-asthmatics in young people in Brazil. Asthma was associated with higher Bacteroides which correlated with nasal IL-4 concentration.

The primary ciliary dyskinesia-related genetic risk score is associated with susceptibility to adult-onset asthma.

Disturbance of mucociliary clearance is an important factor in the pathogenesis of asthma. We hypothesized that common variants in genes responsible for ciliary function may contribute to the development of asthma with certain phenotypes. Three independent adult Japanese populations (including a total of 1,158 patients with asthma and 2,203 non-asthmatic healthy participants) were studied. First, based on the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/), we selected 12 common single-nucleotide polymorphisms (SNPs) with molecular consequences (missense, nonsense, and 3'-untranslated region mutation) in 5 primary ciliary dyskinesia (PCD)-related genes and calculated a PCD-genetic risk score (GRS) as a cumulative effect of these PCD-related genes. Second, we performed a two-step cluster analysis using 3 variables, including PCD-GRS, forced expiratory volume in 1 second (%predicted FEV1), and age of asthma onset. Compared to adult asthma clusters with an average PCD-GRS, clusters with high and low PCD-GRS had similar overall characteristics: adult-onset, female predominance, preserved lung function, and fewer features of type 2 immunity as determined by IgE reactivity and blood eosinophil counts. The allele frequency of rs1530496, a SNP representing an expression quantitative trait locus (eQTL) of DNAH5 in the lung, showed the largest statistically significant difference between the PCD-GRS-High and PCD-GRS-Low asthma clusters (p = 1.4 x 10-15). Genes associated with PCD, particularly the common SNPs associated with abnormal expression of DNAH5, may have a certain influence on the development of adult-onset asthma, perhaps through impaired mucociliary clearance.

Household adult smoking behaviors and prevalence of asthma in Greek schoolchildren: five surveys during 1998-2018.

Environmental tobacco smoke exposure is a well-recognized risk factor for asthma development and poor asthma control in children. However, the relationship between changes in parental smoking habits over time and the prevalence of childhood asthma remains largely unknown. Our objective was to investigate the trends of parental smoking behaviors in relation to childhood wheeze/asthma rates over a 20-year period. A standardized questionnaire on household overall smoking and household indoor tobacco smoking (HITS) habits was distributed to 8-9-years-old school children in the context of five cross-sectional surveys conducted in 1998 (n=3,076), 2003 (n=2,725), 2008 (n=2,688), 2013 (n=2,554) and 2018 (n=2,648). The parental overall smoking and HITS rates have substantially decreased during the study period (p-for-trend<0.001). However, while HITS declined among the fathers of asthmatic and non-asthmatic children as well as among the mothers of non-asthmatic ones (p-for-trend<0.001), it remained unchanged in the case of the mothers of asthmatic participants (p-for-trend 0.283). The mothers of asthmatic children consistently reported more HITS than those of non-asthmatic participants, while prevalence changes of current wheeze/asthma over the surveillance period were in complete agreement with changes in maternal HITS (cross-correlation coefficient 0.918 at zero-year lag) but not with paternal smoking behaviors. Overall and indoor smoking rates of school children's adult family members declined substantially during the 1998-2018 period in Greece. However, no such trend was noted among mothers of asthmatic children, while temporal changes in maternal indoor smoking rates occurred in parallel with those of childhood asthma prevalence.

Asthma burden according to treatment steps in the French population-based cohort CONSTANCES

BackgroundData on health care consumption and costs of asthma in the French population are scarce. ObjectivesThe study objective was to describe the burden of asthma according to GINA treatment steps in the CONSTANCES cohort. MethodsData from 162,725 participants included between 2012 and 2019 were extracted. Participants were considered as current asthmatics if asthma was reported at inclusion and asthma symptoms and/or treatments were reported in 2019. Participants were classified in three categories according to GINA treatment steps. The results were compared to non-asthmatic participants matched with a propensity score calculated on age, sex, region of residence, precariousness score and year of inclusion. ResultsAmong 162,725 participants aged 18–69 years, 6783 asthmatics (1566 not treated for asthma, 2444 + 251 GINA steps 1 + 2, 1054 + 1315 GINA steps 3 + 4, and 153 GINA step 5) were matched with 6783 controls. Average annual ambulatory cost and average annual hospitalization cost were respectively €1925 and €719 for asthmatics versus €1376 and €511 for participants without asthma (p < 0,0001). Cardiovascular risk factors, co-morbidities, visits and hospitalizations were higher for asthma participants as compared to controls and increased with GINA steps, as well as inpatient and outpatient costs. However, for cardiovascular risk factors and co-morbidities, differences were non-significant in multivariate analyses. Pharmacy costs were ten times higher for GINA step 5 participants than for GINA steps 1–2 participants: €3187 versus €393 (p < 0,0001). Conclusionmean cost of asthma was estimated at €757 per patient/year and increased with GINA treatment step.

Association between asthma and generalized anxiety disorder-7 (GAD-7) in Korean adolescents

Background Asthma is known to be associated with a variety of psychological disorders, such as anxiety, but the association between adolescent asthma and anxiety has not been investigated in detail. Methods We analyzed 2,322 physician-diagnosed adolescent asthma patients and 38,696 non-asthmatic adolescent participants from the 2020 Korean Youth Risk Behavior self-administered Survey. Anxiety status was assessed using the Generalized Anxiety Disorder-7 (GAD-7) questionnaires. Multiple logistic regression analyses with complex sampling was performed with adjustments for multiple confounding variables (socioeconomic, health behavior, and psychological factors) to explore the association between GAD-7 scores and adolescent asthma. Results The asthma group had higher rates of anxiety (GAD-7 score ≥ 10) than the non-asthma group (5.0% and 6.7%, respectively; p < 0.001). After adjustment for multiple confounders, asthma was significantly associated with an increased risk of anxiety (GAD-7 score ≥ 10) (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.06–1.12). Conclusion Asthma is associated with an increased prevalence of anxiety in Korean adolescents.

The risk of respiratory tract infections and antibiotic use in a general population and among people with asthma.

AimThe aim of this study was to investigate occupational, environmental, early life and other risk factors associated with respiratory infections and antibiotics use in a general population and among asthmatic individuals.MethodThis study included 15 842 participants of the Respiratory Health in Northern Europe (RHINE) study aged 25–54 years from five Nordic countries, who answered a questionnaire covering respiratory outcomes, exposures, demographic characteristics and numbers of infections and courses of antibiotics in the last 12 months. Multiple logistic regression with and without adjustment for age, sex, smoking status, body mass index and centre were used to study the risk of infection and antibiotics in relation to asthma, and also the association between infection and antibiotics and occupations.ResultsIn the whole population, 11.6% reported having three or more respiratory infections, and 14.7% had used antibiotics because of respiratory tract infections within the last year. Asthmatic participants reported tripled odds for such infections (adjusted OR 2.98, 95% CI 2.53–3.52) and antibiotics use (adjusted OR 3.67, 95% CI 3.18–4.24) as compared to non-asthmatic participants. Both in the general and the asthmatic population, female sex, obesity and exposure to building dampness were associated with respiratory infections. Female sex and current smoking and living in Tartu were associated with antibiotic use. The use of antibiotics was doubled in people hospitalised for severe respiratory infection in childhood.ConclusionIn this study we identified several factors associated with increased respiratory infections and use of antibiotics in a general population and among asthmatic individuals. The frequency of respiratory infections and subsequent antibiotic treatment were increased among those with asthma.

Sleep duration patterns from adolescence to young adulthood and the risk of asthma

PurposeThis study examined the association between sleep duration trajectories from adolescence to young adulthood and the risk of asthma into young adulthood. MethodsUsing data from 10,362 participants in the National Longitudinal Study of Adolescent to Adult Health (Add Health) free of asthma at baseline, we constructed trajectories of sleep duration from adolescence (age 13–18 years) to young adulthood (age 24–32 years) and used them to examine the association between sleep duration patterns and the risk of new-onset asthma using a log-binomial regression model after adjusting for potential confounders. ResultsThe results revealed that 14.4% of nonasthmatic participants had persistent short sleep duration, whereas 80.0% had adequate sleep duration from adolescence through young adulthood. Consistently short-sleepers had 1.52 times the risk of new-onset asthma by age 32 years (95% CI 1.11, 2.10) compared with consistently adequate sleepers. The association was stronger in those with a family history of asthma (aRR = 2.43, 95% CI 1.15, 5.13) than in those without such history (aRR = 1.43, 95% CI 1.05, 1.95). ConclusionsWe conclude that persistent short sleep duration is associated with an increased risk of new-onset asthma in young adults. This association may be more pronounced among those at high risk of asthma because of family history.

Impact of asthma and its medication on salivary characteristics and oral health in adolescents: A cross-sectional comparative study.

To assess and compare the salivary characteristics and oral health and to evaluate the impact of asthma and its medication on dental caries among adolescents with and without asthma. A cross-sectional comparative study was conducted among 50 asthmatic and 50 nonasthmatic adolescents aged 12-15 years in Bangalore City. Data were acquired using a structured questionnaire. Salivary samples were collected to determine the flow rate, pH, buffering capacity, and Streptococcus mutans and Lactobacilli counts. Oral health assessment was performed using WHO 2013 proforma. Inferential statistics such as chi-square, student's t-test, spearman's correlation, multinomial logistic. and stepwise linear regression were applied with P<.05 considered as significant. Asthmatic participants had significantly higher mean number of teeth with dental caries, gingival bleeding, and dental erosion than nonasthmatics (P<.05). The prevalence of fluorosis, traumatic dental injuries, and oral mucosal lesions in asthmatics were 34.0%, 38.0%, and 28.0%, respectively. Most of the asthmatic participants required preventive or routine (18.0%) and prompt treatment (30.0%). Statistically significant difference was found in the flow rate, pH, buffering capacity, S. mutans and Lactobacilli counts, and Decayed, Missing, Filled Teeth (DMFT) index between asthmatic and nonasthmatic participants. Severity of asthma, medication use, and dental caries experience significantly correlated with low salivary flow rate, pH and buffering capacity, and higher levels of S. mutans and Lactobacilli (P<.001). Asthmatic participants had significantly higher odds of having very low unstimulated salivary flow rate (odds ratio [OR]=3.2), buffering capacity (OR=2.94), highly acidic pH (OR=3.65), high risk of S. mutans (OR=6.02), and DMFT≥1 (OR=2.06) than nonasthmatics (P<.05). Salivary characteristics and oral health were significantly poor in asthmatic adolescents. Asthma and its medications had significant impact on salivary characteristics and dental caries among asthmatic adolescents.

Exposure to second-hand smoke among patients with asthma: a cross-sectional study

Background: The prevalence of asthma varies among different regions based on the presence of different risk factors. Second-hand smoking is one of the factors that leads to an increased prevalence, exacerbation, and poor control of asthma. Thereby, this study aimed to investigate the prevalence of asthma among children and the impact of second-hand smoking among asthma patients. Methodology: This cross-sectional study included parents of children in Saudi Arabia. It was conducted during the period from July 2020 to September 2020 using an online questionnaire. Results: This study included 300 participants; of which 33.3% children were suffering from asthma. There was no significant difference between asthmatic and non-asthmatic participants regarding being exposed to daily smokers, occasional smokers, or non-smokers (p = 0.14). There was no significant difference between asthmatic and non-asthmatic patients regarding being exposed to daily smokers, occasional smokers, or nonsmoker parents (p = 0.16). There was no significant difference between asthmatic and non-asthmatic children regarding being exposed to daily smokers, occasional smokers, or non-smokers inside the car (p = 0.4). Conclusion: Second-hand smoking showed no impact on the prevalence and exacerbation of asthma.

Chronic rhinosinusitis exacerbations are differentially associated with lost productivity based on asthma status.

The frequency of chronic rhinosinusitis (CRS) exacerbations is an independent predictor of quality of life. The objective of this study was to evaluate if increased CRS exacerbations predict decreased productivity. Cross-sectional study of adult CRS patients. Number of patient-reported CRS-related antibiotic and oral corticosteroids courses and sinus infections in the past three months were used as metrics for acute exacerbations of CRS (AECRS). Productivity loss was measured by asking participants the number of lost days of work or school due to CRS in the past three months. Associations were sought between lost productivity and AECRS, controlling for clinical and demographic characteristics. 371 participants were recruited. 28.8% of study participants had comorbid asthma. The mean number of lost days of productivity due to CRS in the last three months was 1.5 for asthmatic participants and 2.4 for non-asthmatic participants. In asthmatics, CRS-related lost productivity was significantly associated with number of CRS-related antibiotics used (and oral corticosteroids used, with a trend for sinus infections. No AECRS metric was significantly associated with lost productivity in non-asthmatics. However, when focusing on non-asthmatics reporting missed days of work or school due to CRS, we found statistically significant associations between AECRS metrics and lost productivity. The frequency of AECRS is associated with CRS-related lost productivity in asthmatics and in the subset of non-asthmatics with moderate CRS-related productivity losses.

Efficacy of an exercise intervention among children with comorbid asthma and obesity

ObjectivesChildren with comorbid asthma and obesity present with more severe and harder-to-control disease than asthmatic children at healthy weight. Weight loss has been shown to improve asthma symptoms, yet physical activity may be difficult due to exercise-induced bronchospasm. Children with asthma have lower exercise rates than non-asthmatics. The objective of this study was to retrospectively evaluate attrition rates and program outcome measures (Body Mass Index [BMI] and maximum oxygen consumption [VO2max]) among asthmatic and non-asthmatic participants. Study designClinical data were collected from the Healthy Hearts Program, a 12-week nutrition and activity intervention program for children who are overweight, obese, or at risk for heart disease and other conditions, and used for the study. MethodsIntervention data and demographics were obtained from medical records at the Children's Heart Center Nevada. Descriptive statistics, paired t-tests, Cox regression analysis, and analysis of covariance were conducted. ResultsThe mean age of this population (N = 232) was 11 years; 54% were male, 64% were Hispanic, and 37% had asthma. Median time in the program was 9 weeks, and 58% of the population completed the program. Unadjusted analyses showed significant BMI decreases in asthmatic (P = 0.002) and non-asthmatic (P = 0.001) participants and increases in cardiorespiratory function for asthmatic males and females (P = 0.003, P = 0.004) and non-asthmatic males and females (P < 0.001 for both). Asthmatic and non-asthmatic children both had improved exercise intensity (P = 0.033, P < 0.001). ConclusionsThis program is both beneficial and practical for obese children with asthma for losing weight and improving cardiorespiratory function.

The effect of glycopyrronium and indacaterol, as monotherapy and in combination, on the methacholine dose-response curve of mild asthmatics: a randomized three-way crossover study

BackgroundMethacholine dose-response curves illustrate pharmacologic bronchoprotection against methacholine-induced airway hyperresponsiveness and can be used to quantitate changes in airway sensitivity (position), reactivity (slope), and maximal responsiveness following drug administration. Our objective was to determine the influence of single-dose glycopyrronium (long-acting muscarinic antagonist) and indacaterol (ultra-long acting β2 agonist), as monotherapy and in combination, on the methacholine dose-response curve of mild asthmatics and to compare these findings with a non-asthmatic control curve.MethodsThis was a randomized, double blind, double dummy, three-way crossover study. For asthmatic participants (n = 14), each treatment arm included a baseline methacholine challenge, drug administration, and repeat methacholine challenges at 1, 24, and 48 h. Non-asthmatic control participants (n = 15) underwent a single methacholine challenge and did not receive any study treatment. Methacholine dose-response curves were graphed as the percent fall in forced expiratory volume in 1 s (FEV1) for each methacholine concentration administered. Best-fit curves were then generated. Differences in airway reactivity were calculated through linear regression. Changes in airway sensitivity were assessed as the shift in the provocative concentration of methacholine causing a 20% fall in FEV1.ResultsCompared to baseline, all treatments significantly reduced airway sensitivity to methacholine at 1 h post-dose (indacaterol ~1.5 doubling concentrations; glycopyrronium ~5 doubling concentrations; combination ~5 doubling concentrations). Bronchoprotection at 24 and 48 h remained significant with glycopyrronium and combination therapy only. Airway reactivity was not influenced by indacaterol whereas glycopyrronium significantly reduced airway reactivity at all time-points (p = 0.003-0.027). The combination significantly decreased slope at 1 (p = 0.021) and 24 (p = 0.039) hours only. The non-asthmatic control and 1-h glycopyrronium curves are nearly identical. Only the non-asthmatic control and 1-h post-combination therapy curves appeared to generate a true response plateau (three data points within 5%), which occurred at a 14% fall in FEV1.ConclusionsMethacholine dose-response curves differentiate the bronchoprotective mechanisms triggered by different classes of asthma medications. Assessment of bronchoprotection using methacholine dose-response curves may be useful during clinical development of respiratory medications when performing superiority, equivalence, or non-inferiority trials.Trial registrationclinicaltrials.gov (NCT02953041). Retrospectively registered on October 24th 2016.

Determinants of peripheral airway function in adults with and without asthma.

Peripheral airway involvement in asthma remains poorly understood. We investigated impulse oscillometry (IOS) measures of peripheral airway function in a population-based birth cohort. Pre- and post-bronchodilator spirometry and IOS measures of respiratory resistance and reactance were measured in 915 participants at age 38 years. Current asthma was associated with impairments in both spirometry and IOS parameters. These impairments were greater in men and in those with childhood persistent asthma. Spirometry and IOS values for those whose asthma was in remission were not different to non-asthmatic participants. There were significant changes in IOS in both asthmatic and non-asthmatic participants after bronchodilator, but between-group differences persisted. Higher BMIs were associated with impairments in IOS but not spirometry. Cumulative tobacco use was associated with spirometric airflow obstruction in both sexes, whereas cannabis use was associated with impairments in IOS in women. Despite higher lifetime exposure, there were few associations between cannabis and IOS in men. Asthma is associated with abnormalities in IOS measures of peripheral airway dysfunction. This association is stronger in men and in those with asthma persisting since childhood. Tobacco and cannabis use are associated with different patterns of spirometry and IOS abnormalities and may affect the bronchial tree at different airway generations with differences in susceptibility between sexes.

Post-prandial systemic 8-isoprostane increases after consumption of moderate and high-fat meals in insufficiently active males

A single high-fat meal (HFM) leads to an increase in triglycerides and oxidative stress. Oxidative stress can be assessed via 8-isoprostane generation, which is associated with the development of asthma and cardiovascular disease. No previous research has investigated whether airway and systemic 8-isoprostane increases postprandially in nonasthmatic participants according to the energy and fat content of a meal. Our purpose was to assess airway and systemic 8-isoprostane after a HFM and a true-to-life moderate-fat meal (MFM). We hypothesized that airway and systemic 8-isoprostane would increase after a HFM and a MFM, with the greatest increase in the HFM condition. Eight nonasthmatic men (25.8±6.9years) completed the HFM and MFM trials in a randomized crossover design. After a 10-hour fast, participants consumed either a HFM (71.13kJ/kg body mass, 60% fat, 23% CHO) or a MFM (35.56kJ/kg body mass, 30% fat, 52% CHO). Exhaled breath condensate to assess airway 8-isoprostane was collected at baseline and at 3 and 6hours postmeal. Venous blood samples were collected at baseline and hourly until 6hours postmeal to assess triglycerides, and every 3hours for systemic 8-isoprostane. Airway 8-isoprostane responses were not significant as a main effect of time (P=.072), between conditions (P=.365), or between time and condition (P=.319) postmeal. Systemic 8-isoprostane increased over time (P<.001), but not between conditions (P=.124) or between time and condition (P=.649) postmeal. Triglyceride incremental area under the curve was different in the HFM compared to the MFM condition (P=.013). After a HFM and a MFM, 8-isoprostane increases systemically; however, airway 8-isoprostane does not change.

The relationship between body fat and respiratory function in young adults.

The relationship between adiposity and respiratory function is poorly understood. Most studies investigating this have used indirect measures of body fat and few have assessed how changes in adiposity influence lung function.Body fat measured by bio-electrical impedance analysis, body mass index, waist circumference, spirometry, body plethysmography and transfer factor were measured at ages 32 and 38 years in 361 non-smoking, non-asthmatic participants from a population-based birth cohort.Higher percentage body fat was associated with lower spirometric and plethysmographic lung volumes, but not with airflow obstruction, or transfer factor at 32 years. Changes in adiposity between ages 32 and 38 years were inversely associated with changes in lung volumes. These associations were generally stronger in men than women, but an association between increasing adiposity and lower airway function (forced expiratory volume in 1 s/forced vital capacity) was only found in women. Similar associations were found for body mass index and waist circumference.Higher percentage body fat is associated with lower lung volumes. Direct and indirect measures of adiposity had similar associations with lung function. Adiposity had a greater effect on lung volumes in men than women but was associated with airway function only in women. There was little evidence that adiposity influenced transfer factor.

Effect of Submaximal Warm-up Exercise on Exercise-induced Asthma in African School Children.

Regular physical activity has long been regarded as an important component of a healthy lifestyle. Exercise-induced asthma (EIA) is one of the major problems interfering with the performance of exercise. A warm-up exercise programme has been cited as a non-pharmacologic means of reducing EIA, but its effect has not been fully elucidated. The aims of this study were to determine the prevalence of unrecognized EIA in Pretoria primary school children, determine the effect of a warm-up exercise programme on EIA and to establish the relationship between history of allergy, family history of asthma and EIA. A random sample of 640 school children was selected. The study was divided into three phases. In phase one, a descriptive cross-sectional study was done using the standardized European Community Respiratory Health Survey (ECRHS) questionnaire. In phase two, non-asthmatic participants that returned a completed questionnaire were included in the field study. Pre-test and post-test experimental designs were used, where peak expiratory flow rate (PEFR) was measured at baseline and within ten minutes after exercise. A total of 340 subjects completed the Free Running Asthma Screening Test (FRAST); EIA was defined as a decrease in baseline PEFR ≥ 10% after exercise and 75 children (22%) had EIA. In phase three, 29 of the 75 subjects participated in the warm-up programme which was performed in the laboratory and subjects acted as their own controls. Predefined protocols for the study were followed. Seventy-five (22%) of the 340 participants had EIA. The mean age, height and weight were 10.51 years, 139.26 cm and 33.45 kg, respectively. Exercise-induced asthma symptoms were cough (25%), chest pain (16%), wheeze (12%) and chest tightness (12%). The history of allergy was 75%, family history of allergy 40% and positive history of allergy when near animals, feathers or in dusty areas 38%. Wheezing during or after exercise, wheezing when near animals, feathers or in dusty areas and chest pain was significant (p < 0.05). The mean PEFR after exercise without warm-up was 4.43 L/min. The mean PEFR after exercise (warm-up) was 4.98. The mean percentage change in PEFR between exercise without warm-up and exercise with warm-up was 14.83%. The paired t-test showed a significant difference between PEFR with warm-up and PEFR without warm-up (p < 0.05). There was a high prevalence of EIA among study participants. Exercise-induced asthma symptoms were significant for wheezing and chest pain. Exercise after warm-up was significant in reducing EIA. This study reports the effect of warm-up exercise on EIA and highlights the need to screen school children for EIA.

Relationship between airway neutrophilia and ageing in asthmatics and non‐asthmatics

Increased sputum neutrophilia has been observed in asthma, but also during normal ageing in asthmatics and non-asthmatics. It remains unclear what constitutes 'normal' neutrophil levels in different age groups. We assessed the relationship between age and airway neutrophils of 194 asthmatics and 243 non-asthmatics (age range: 6-80 years). Regression analyses were used to assess this relationship adjusted for confounders including asthma status, atopy, gender, smoking and current use of inhaled corticosteroids (ICS). Age-corrected reference values for different age groups were determined using the 95th percentile of non-asthmatic participants. Age was positively associated with sputum neutrophils in both asthmatic and non-asthmatic adults (0.46% neutrophil increase/year (95% confidence interval (CI) 0.18, 0.73) and 0.44%/year (0.25, 0.64, respectively), but no association was found in the <20-year age category. Individuals with high sputum neutrophil counts (>95th percentile of non-asthmatic counts for any given age group) were significantly more likely to be asthmatic (odds ratio = 2.5; 95% CI: 1.3, 5.0), with the greatest effect observed in the older age group. Other factors that independently associated with increased sputum neutrophil levels included atopy in non-asthmatic adults, male gender and current use of ICS in asthmatic adults. Age-specific reference values for neutrophil percentage were under 20 years-76%, 20-40 years-62%, 40-60 years-63% and over 60 years-67%. Airway neutrophilia is related to age in adults, with a neutrophilic asthma phenotype present in older adults. The use of appropriate age-specific reference values is recommended for future studies aimed at elucidating the role of neutrophils in asthma.

Formoterol Concentrations in Blood and Urine

We examined urinary and serum concentrations of formoterol in asthmatic and healthy individuals after a single dose of 18 μg inhaled formoterol and after repeated inhaled doses in healthy individuals. Results were evaluated using the World Anti-Doping Agency (WADA) 2012 threshold for formoterol. On the day of this open-label, crossover study, 10 asthmatic subjects who regularly used beta2-agonists and 10 healthy participants with no previous use of beta2-agonists received a single dose of 18 μg formoterol. Further, 10 nonasthmatic participants inhaled 18 μg formoterol every second hour until obtaining a total of 72 μg, which is twice the maximum daily dose (36 μg formoterol) permitted by the WADA. Blood samples were collected at baseline, 30 min, 1, 2, 3, 4, and 6 h after the first inhalation. Urine samples were collected at baseline, 0-4, 4-8, and 8-12 h after the first inhalation. Median urine concentration, corrected for specific gravity, after the single-dose administration peaked during 0-4 h after inhalation at a maximum of 7.4 ng·mL(-1) in asthmatic subjects and 7.9 ng·mL(-1) in healthy subjects. Median urine concentration after repeated doses peaked during 4-8 h after inhalation of a total of 72 μg formoterol at a maximum of 16.8 ng·mL(-1) in healthy participants. The maximum individual concentration of 25.6 ng·mL(-1) was found after inhalation of a total of 72 μg formoterol. We found no significant differences in urinary and serum concentrations of formoterol between asthmatic and healthy subjects. We found high interindividual variability in the concentrations in all groups. Our data support the WADA 2012 urinary threshold of 30 ng·mL(-1) formoterol as being an adverse analytical finding.

Occupational Exposure to Dusts, Gases, and Fumes and Incidence of Chronic Obstructive Pulmonary Disease in the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults

There is limited evidence from population-based studies demonstrating incidence of spirometric-defined chronic obstructive pulmonary disease (COPD) in association with occupational exposures. We evaluated the association between occupational exposures and incidence of COPD in the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). Prebronchodilator ratio of forced expiratory volume in 1 second over forced vital capacity (FEV(1)/FVC) was measured in 4,267 nonasthmatic SAPALDIA participants ages 18-62 at baseline in 1991 and at follow-up in 2001-2003. COPD was defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criterion (FEV(1)/FVC < 0.70) and Quanjer reference equation (FEV(1)/FVC < lower limit of normal [LLN]), and categorized by severity (≥ 80% and <80% predicted FEV(1) for stage I and stage II+, respectively). Using a job-exposure matrix, self-reported occupations at baseline were assigned exposures to biological dusts, mineral dusts, gases/fumes, and vapors, gases, dusts, or fumes (VGDF) (high, low, or unexposed as reference). Adjusted incident rate ratios (IRRs) of stage I and stage II+ COPD were estimated in mixed Poisson regression models. Statistically significant (P < 0.05) IRRs of stage II+ GOLD and LLN-COPD, indicating risks between two- and fivefold, were observed for all occupational exposures at high levels. Occupational exposure-associated risk of stage II+ COPD was observed mainly in males and ages ≥ 40 years, and remained elevated when restricted to nonsmokers. In a Swiss working adult population, occupational exposures to biological dusts, mineral dusts, gases/fumes, and VGDF were associated with incidence of COPD of at least moderate severity.