Higher Prevalence Of Bronchial Hyperresponsiveness Research Articles

Blood eosinophils associate with reduced lung function growth in adolescent asthmatics.

Background and ObjectiveSome children with asthma have low lung growth, putting them at increased risk for COPD later in life. However, it is currently not clear who will experience this adverse growth pattern. We therefore investigated the predictive role of blood eosinophils as a type 2 inflammation marker in lung growth, focusing on the presence and severity of asthma.MethodsWe investigated blood eosinophils and lung function growth (percentage of predicted values) using linear mixed models in children and adolescents from two longitudinal cohorts. One cohort was hospital‐based and consisted of asthmatic children at their first outpatient clinic visit after referral by the general practitioner (n = 133, mean age 9.8), while the second was a general population‐based birth cohort (PIAMA, asthma n = 52 and non‐asthma n = 433, mean age 8.1). The hospital‐based cohort had not been treated with inhaled corticosteroids (ICS) before referral.ResultsSubjects in the hospital‐based asthma cohort had more severe asthma compared with the asthmatic subjects in the population‐based cohort, defined by lower lung function levels and a higher prevalence of bronchial hyper‐responsiveness. In the asthma cohort, higher blood eosinophil numbers were associated with less growth in FEV1 (estimated change in lung function per 1 unit increase in ln blood eosinophils (B): −0.66%/year (95% confidence interval (CI): −1.11 to −0.20, p < .01)) and FVC (B: −0.40%/year (95% CI: −0.75 to −0.05), p = .025)) during follow‐up in adolescence (min 7, max 17 years). These associations were not observed in the general population‐based birth cohort, regardless of asthma status during follow‐up (age 8–16).Conclusions and Clinical RelevanceBlood eosinophil counts in children with asthma not treated with ICS at referral were predictive of lower growth in FEV1 and FVC during follow‐up in adolescence. Our findings indicate that this association is dependent on the degree of asthma severity. Future studies should address whether anti‐eosinophilic treatments preserve lung function growth in children with asthma.

A high prevalence of airway hyperresponsiveness in cross country skiers

The aim of the study was to evaluate prevalence and age-dependence of bronchial hyperresponsiveness (BHR) in cross country skiers. Methods. Twenty-nine cross-country skiers (14 males, 15 females aged 18 to 30 years; average age, 23.9 ± 3.4 years) were involved in the study. All athletes underwent pulmonary function tests (spirometry before and after inhalation of 400 μg of salbutamol, body plethysmography, diffusion test). Then, methacholine challenge test was performed. Results. In skiers, lung function data were higher compared to the reference vаlues calculated in accordance with the ECSC equations, 1993. Bronchial reversibility was found in 4 athletes (14%). Methacholine provocative concentration causing a 20% fall in FEV1 (PC20) was &gt; 4 mg/ml in 9 skiers (31%). Significant relationships were found between the atheltes’ age and BHR. Conclusion. Cross-country skiers have a high prevalence of BHR to methacholine. BHR increases with age.

Bronchial Asthma and Bronchial Hyperresponsiveness and Their Characteristics in Patients with Common Variable Immunodeficiency

Background: Common variable immunodeficiency (CVID) is one of the most frequent primary immunodeficiencies and is characterized by disturbed immunoglobulin production and dysregulation of the immune system. Results of previous studies suggest a higher prevalence of bronchial asthma (BA) in CVID patients than in the general population. We initiated this study to evaluate lung functions and identify risk factors for BA and bronchial hyperresponsiveness (BHR) in patients with CVID. Methods: Twenty-three patients with CVID were included in this study. In all of them, spirometry and a metacholine bronchoprovocation test were performed. We also investigated the role of atopy, eosinophilic inflammation, and potential risk factors such as gender, age, or immunoglobulin levels at the time of diagnosis. Results: BHR was confirmed in 12 patients (52%), all of whom had normal FEV₁ and FEV₁/FVC. However, BHR-positive patients had significantly decreased MEF25. BHR-positive patients had also more symptoms related to bronchial obstruction, with 8 of them (35%) being suspected of having BA at the end of the study. A higher prevalence of BHR was found in females, with a relative risk of 2.89. Conclusions: An increased prevalence of BHR and BA was detected in CVID patients compared to the general population. BA may develop despite the disturbed immunoglobulin production, and the majority of patients display nonatopic and noneosinophilic properties. These results suggest a limited role of atopy and eosinophilic inflammation in the pathogenesis of BA in CVID patients.

Lung Function and Bronchial Hyperresponsiveness in Adults Born Prematurely. A Cohort Study.

Bronchopulmonary dysplasia and the long-term consequences of prematurity are underrecognized entities, unfamiliar to adult clinicians. Well described by the pediatric community, these young adults are joining the ranks of a growing population of adults with chronic lung disease. To describe the quality of life, pulmonary lung function, bronchial hyperresponsiveness, body composition, and trends in physical activity of adults born prematurely, with or without respiratory complications. Four groups of young adults born in Canada between 1987 and 1993 were enrolled in a cohort study: (1) preterm subjects with no neonatal respiratory complications, (2) preterm subjects with neonatal respiratory distress syndrome, (3) preterm subjects with bronchopulmonary dysplasia, and (4) subjects born at term. The following measurements were compared across the four groups: health-related quality of life, respiratory health, pulmonary function, methacholine challenge test results, and sedentary behavior and physical activity level. Adult subjects who had bronchopulmonary dysplasia in infancy had mild airflow obstruction (FEV1, 80% predicted; FEV1/FCV ratio, 70) and gas trapping compared with others. They also had less total active energy expenditure and more time spent in sedentary behavior compared with subjects born at term. All preterm groups had a high prevalence of bronchial hyperresponsiveness compared with term subjects. In a population-derived, cross-sectional study, we confirmed previous reports that adults 21 or 22 years of age who were born prematurely with neonatal bronchopulmonary dysplasia are more likely to have airflow obstruction, bronchial hyperresponsiveness, and pulmonary gas trapping than subjects born prematurely without bronchopulmonary dysplasia or at term. Clinicians who care for adults need to be better informed of the long-term respiratory consequences of premature birth to assist young patients in maintaining lung function and health.

Exposure to Beta-(1,3)-D-glucan in house dust at age 7-10 is associated with airway hyperresponsiveness and atopic asthma by age 11-14.

BackgroundMould exposure has been linked to childhood asthma and bronchial hyper-responsiveness. Few studies have assessed beta-(1,3)-d-glucan (beta-glucan), a significant fungal cell wall constituent, in relation to asthma in adolescence.ObjectiveTo determine whether house dust-derived beta-glucan exposure at age 7–10 is associated with the development and persistence of atopic and non-atopic asthma, and bronchial hyper-responsiveness (BHR) by age 11–14.MethodsDust samples were collected from the 1995 Study of Asthma, Genes, and Environment (SAGE) birth cohort. This cohort was derived from Manitoba provincial healthcare administrative records of children high and low risk for asthma. Samples were collected from the homes of 422 children at age 7–10 and analyzed using beta-glucan and endotoxin-specific Limulus Amoebocyte Lysate assays. Asthma, atopy, and BHR status of each child were also assessed at ages 7–10 and 11–14.ResultsAt age 7–10, beta-glucan dust levels in the home were associated with persistent atopic asthma at age 11–14 (OR 1.79 for each unit increase in levels, 95% CI 1.14–2.81), independent of endotoxin exposure, and Alternaria or Cladosporium sensitization. The likelihood of BHR almost doubled with unit increases in dust beta-glucan in asthmatic children. In children without asthma, exposure to high beta-glucan levels at age 7–10 also elevated risk for BHR in adolescence (OR 1.74, 95% CI 1.05–2.89). New-onset atopic asthma was twice more likely following high beta-glucan exposure in children without asthma but the association did not reach statistical significance. No associations were evident with concurrent asthma phenotype at age 7–10 or non-atopic asthma at age 11–14.ConclusionThese findings implicate home beta-glucan exposure at school-age as a risk factor for persistent atopic asthma and new-onset BHR. The higher prevalence of BHR in urban adolescents may be propagated by this home exposure.

Factors Affecting Bronchial Hyperresponsiveness in Rhinitis Patients

Background and ObjectivesZZMany studies have revealed a close relationship between allergic rhinitis (AR) and asthma. This study was designed to evaluate clinical parameters affecting bronchial hyperresponsiveness (BHR) in patients with rhinitis symptoms. Subjects and MethodZZOne hundred thirty-seven patients who visited the outpatient clinic due to rhinitis symptoms were evaluated retrospectively. All patients undertook an allergic skin test, the methacholine bronchial provocation test and were tested for clinical parameters such as allergic symptoms, IgE levels, and sinonasal outcome test-20 were evaluated. ResultsZZPatients with AR had a higher proportion of BHR than the non-allergic group (28.0% vs. 4.5%, p=0.001) did, and children had higher prevalence of BHR than adults (p ＜0.005) did. There was no significant difference according to the type of allergen. Sinusitis or nasal polyp did not influence BHR and there were no significant differences according to the Allergic Rhinitis and Its Impact on Asthma classification. The mean serum eosinophil count was significantly higher in BHR group. ConclusionZZPatients with AR had more BHR, and age and serum eosinophil counts were related to BHR. Hence, the additional evaluation of lower airway might be required in high risk patients of BHR, such as pediatric AR patients and patients with elevated eosinophil counts. � Korean J Otorhinolaryngol-Head Neck Surg 2014;57(3):160-5 Key WordsZZAllergic rhinitis ㆍAsthma ㆍBronchial responsiveness.

Respiratory Symptoms and Bronchial Responsiveness in Competitive Swimmers

A high prevalence of bronchial hyperresponsiveness (BHR) and respiratory symptoms has been reported among competitive swimmers. From the 2002 Winter Olympics, BHR measurements or bronchodilator reversibility have been required for approved use of β2-agonists in sports. The first aim of this study was to evaluate the relationship among respiratory symptoms in young elite swimmers, eucapnic voluntary hyperpnea (EVH), and the inhaled dose of methacholine, causing a 20% decrease in forced expiratory volume in 1 s (FEV1; PD(20 methacholine)). The second aim of this study was to assess the repeatability of the EVH test. For this study, 15 male and 9 female adolescent elite swimmers, aged 15 to 25 yr, performed one PD(20 methacholine) test and two EVH tests in a randomized order. Dry air containing 5% CO2 was inhaled for 6 min with a target ventilation of ≥85% of maximum voluntary ventilation (minimum = 65%). PD(20 methacholine) ≤2 μmol and EVH with FEV1 reduction ≥10% were considered positive. Respiratory symptoms and medication were reported in the modified AQUA2008 questionnaire. Twenty swimmers (83%) reported respiratory symptoms, 13 (65%) of them had a positive provocation test. Fourteen (58%) had at least one positive test to either EVH or PD(20 methacholine); three had only one positive EVH test. One athlete had BHR without symptoms. The sensitivity of PD(20 methacholine) ≤2 μmol for respiratory symptoms was 50% versus 60% and 47.37% for the two EVH tests, respectively, and 75% for PD(20 methacholine) ≤4 μmol. The Bland-Altman plot of the two EVH tests showed a consistent distribution, with only one subject outside the limits of agreement. BHR was frequently found among adolescent competitive swimmers. PD(20 methacholine) ≤2 μmol and EVH ≥ 10% compared well, but PD(20 methacholine) ≤4 μmol had the highest sensitivity for respiratory symptoms. The EVH test has high repeatability but is very expensive and uncomfortable to perform.

Respiratory function and bronchial responsiveness among industrial workers exposed to different classes of occupational agents: a study from Algeria

Occupational exposures play a role in the onset of several chronic airway diseases. We investigated, in a cross-sectional study, lung function parameters and bronchial hyper-responsiveness to histamine in workers exposed to different airborne compounds.The study group totalled 546 male subjects of whom 114 were exposed to welding fumes, 106 to solvents, 107 to mineral dust, 97 to organic dust and 123 without known exposure to airway irritants. A questionnaire was administered and spirometry and bronchial responsiveness to histamine were assessed by one observer, in the morning before work to prevent effects of acute exposure.The mean (SD) age of the participants was 39.3 (7.8) years, with a mean duration of employment of 13.8 (6.6) years. Both before and after adjustment for smoking status, forced expiratory volume in 1 second (FEV1, expressed as % predicted) was lower in welders -4.0% (95% confidence interval [CI], -6.3 to -1.8; p = 0.01) and workers exposed to solvents -5.6% (CI: -7.9 to -3.3; p = 0.0009) than in control subjects. Furthermore, solvent workers had an odds ratio of 3.43 (95% CI: 1.09–11.6; p = 0.037) for bronchial hyperresponsiveness compared with the reference group.The higher prevalence of bronchial hyperresponsiveness in solvent workers adds to the growing body of evidence of adverse respiratory effects of occupational solvent exposure. These results point to the necessity of preventive measures in solvent workers to avoid these adverse respiratory effects.

Bronchial hyperresponsiveness in children with atopic rhinitis: a 7-year follow-up.

A high prevalence of bronchial hyperresponsiveness (BHR) was found in atopic subjects with rhinitis. Those subjects may be at higher risk for developing bronchial asthma. We evaluated, in a 7-year follow-up, BHR and atopy in a homogeneous population of nonasthmatic children with allergic rhinitis (AR), and their role in asthma development. Twenty-eight children (6-15 years) with AR were studied. At enrollment (T(0)), skin tests, total serum IgE assay, peak expiratory flow (PEF) monitoring and methacholine (Mch) bronchial challenge were performed. BHR was computed as the Mch dose causing a 20% forced expiratory volume (FEV)(1) fall (PD(20)FEV(1)) and as dose-response slope (D(RS)). Subjects were reassessed after 7 years (T(1)) using the same criteria. At T(0), 13 children (46%), showing a PD(20)FEV(1) <1526 microg of Mch, had BHR (Mch+), although PEF variability (PEFv) was within normal limits. None of the children with negative methacholine test developed bronchial asthma after 7 years. Of the 13 Mch+, only two reported asthma symptoms after 7 years. No significant change was seen in the other parameters of atopy considered. Children with allergic rhinitis present a high prevalence of BHR. Nevertheless, their PEFv is normal and the rate of asthma development low.

Irritable Bowel Syndrome and Bronchial Hyperresponsiveness: Is There a Link?

Background/Aim: Many studies have demonstrated a high prevalence of bronchial hyperresponsiveness in patients with irritable bowel syndrome (IBS). The aim of this 24-month prospective study was to evaluate the prevalence of IBS in asthmatic patients. Methods: We analyzed 623 asthmatic patients that were evaluated for body mass index, sex, and age before undergoing both a methacholine challenge test (MCHt) and skin prick tests. Results: We found that 276 asthmatic patients (44.3%) were positive on the MCHt, while 347 (55.7%) were negative. We also found that 27 (9.7%) of the 276 patients with a positive MCHt and 44 (12.7%) of the 347 patients with a negative MCHt were affected by IBS. Therefore, there was no statistically significant difference between positive MCHt tests and IBS. The PC₂₀ (mean provocation concentration of methacholine producing a 20% reduction in forced expiratory volume in 1 s ≤16 mg/ml) in all patients tested was 8.64 ± 2.58 mg/ml, being 8.75 ± 2.52 and 8.55 ± 2.32 mg/ml for males and females, respectively. Conclusions: These results do not demonstrate a relationship between MCHt and IBS. However, a relationship might still exist in a subpopulation of patients whose symptoms worsen by stress.

Effect of nasal triamcinolone acetonide on seasonal variations of bronchial hyperresponsiveness and bronchial inflammation in nonasthmatic children with seasonal allergic rhinitis

Recent evidence suggests that patients with allergic rhinitis have lower airway inflammation and a higher prevalence of bronchial hyperresponsiveness (BHR) regardless of asthma. To investigate markers of lower airway inflammation in nonasthmatic children with seasonal allergic rhinitis (SAR) before and during pollen season and the effect of nasal triamcinolone acetonide on seasonal variations in these parameters. Thirty-two nonasthmatic children with SAR in response to grass and/or weed pollens were recruited and separated into 2 groups. Group 1 was treated with triamcinolone acetonide (220 microg once daily) for 6 weeks, and group 2 received no intranasal corticosteroid treatment. Bronchial responsiveness to methacholine [concentration that caused a decrease in forced expiratory volume in 1 second of 20% (PC20)], eosinophil counts in sputum and peripheral blood, and eosinophil cationic protein (ECP) levels in sputum and serum were measured before and during grass pollen season. Twenty-eight patients completed the study. During the pollen season, methacholine PC20 significantly decreased in both groups when compared with the corresponding preseasonal values (P = .01 and P = .003, respectively). The mean percentage of sputum eosinophils increased significantly during the pollen season compared with preseasonal values in group 1 and group 2 (12.7% +/- 2.1% vs 16.5% +/- 2.1%, P = .007, and 11.0% +/- 2.0% vs 20.2% +/- 1.4%, P = .003, respectively). Median [interquartile ranges (IQR)] sputum ECP levels were significantly higher during the pollen season when compared with the preseasonal values in group 1 and group 2 [7.5 microg/L (3.5-36.0 microg/L) vs 35.5 microg/L (13.0-71.7 microg/L), P = .04, and 18.0 microg/L (6.0-36.0 microg/L) vs 69.0 microg/L (39.0-195.0 microg/L), P = .003, respectively], as were the serum ECP levels [6.0 microg/L (2.0-13.0 microg/L) vs 19.0 microg/L (14.0-43.5 microg/L), P = .004, and 6.0 microg/L (3.0-7.0 microg/L) vs 18.0 microg/L (6.0-36.0 microg/L), P = .001, respectively]. Although the mean number of eosinophils in blood increased during the pollen season in both groups, it was only significant in group 2 (70.0 +/- 20.0 vs 161.6 +/- 29.0, P = .02). Although prophylactic nasal corticosteroid treatment provides significant reduction of nasal symptoms and rescue antihistamine use, there is no significant prevention in the seasonal increase of bronchial inflammation and methacholine BHR.

High Prevalence of Bronchial Hyperresponsiveness and Asthma inIce Hockey Players

High Prevalence of Bronchial Hyperresponsiveness and Asthma inIce Hockey Players

High Prevalence of Bronchial Hyperresponsiveness and Asthma inIce Hockey Players

1. Leuppi JD, 2. Kuhn M, 3. Comminot C, 4. Reinhart WH (1998) Eur Respir J. 12:13–16. [OpenUrl][1][Abstract][2] #### Purpose of the Study To determine if ice hockey players are at increased risk for asthma or exercise-induced asthma because they exercise or play intensively in cold air. ##### Study Population Twenty-six ice hockey players and 24 floor ball players were invited to participate in the study. ##### Methods All subjects were instructed to avoid any medications, including antiasthma drugs, for at least 48 hours before the study. All players were asked to complete a 22-item questionnaire, on their personal history of allergy and smoking habits to identify subjects with a history … [1]: {openurl}?query=rft.jtitle%253DEuropean%2BRespiratory%2BJournal%26rft.stitle%253DEur%2BRespir%2BJ%26rft.issn%253D0903-1936%26rft.aulast%253DLeuppi%26rft.auinit1%253DJ.%26rft.volume%253D12%26rft.issue%253D1%26rft.spage%253D13%26rft.epage%253D16%26rft.atitle%253DHigh%2Bprevalence%2Bof%2Bbronchial%2Bhyperresponsiveness%2Band%2Basthma%2Bin%2Bice%2Bhockey%2Bplayers%26rft_id%253Dinfo%253Adoi%252F10.1183%252F09031936.98.12010013%26rft_id%253Dinfo%253Apmid%252F9701407%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [2]: /lookup/ijlink?linkType=ABST&journalCode=erj&resid=12/1/13&atom=%2Fpediatrics%2F104%2FSupplement_2%2F380.2.atom

Age and bronchial hyperresponsiveness are associated with failure to perform the single breath N2 test in a rural female population.

Because some authors have reported high rates of failure in performing the single breath N2 (SBN2) test in rural areas, the present study aimed at evaluating its acceptability in a female population, unfamiliar with lung function testing, in a rural area of northeastern France. Two hundred ninety-eight women from a rural area volunteered for a preventive medicine examination (91.6% of those invited); four of them were excluded for clinical reasons, and six (2%) were unable to perform spirometry. The protocol included completion of a questionnaire, spirometry with a bronchial reactivity test, skin prick test, and the SBN2 test utilizing a computerized assembly. Although failures caused by the apparatus were few (n = 7, 2.4%) 96 of 281 women (34.1%) were unable to produce two valid SBN2 tests in a series of six attempts. Compared with the group who succeeded in the test (n = 185), women who failed were older and had a higher prevalence of bronchial hyperresponsiveness. Logistic regression confirmed the independent association of these two variables with an inability to perform. We conclude that in a female population completely unfamiliar with lung function testing the SBN2 test has a high rate of failure associated with higher age and the presence of bronchial hyperresponsiveness.

Long-term exposure of adults to outdoor air pollution is associated with increased airway obstruction and higher prevalence of bronchial hyperresponsiveness.

The authors studied the association between long-term exposure (i.e., > 10 y) to outdoor air pollution and the severity of obstructive pulmonary disease and prevalence of bronchial hyperreactivity to beta2 agonists in two groups of adult patients who were of similar ages and who had similar smoking habits. The subjects lived in downtown districts or in the outer suburbs of Marseilles, the neighborhood that contained air samplers. The regions were similar with respect to sulfur dioxide levels, but levels of nitric oxides and particulate matter (10 millimeters or less) were higher in the downtown area than the suburbs. The authors assessed airway obstruction, as determined by a decrease in forced expiratory volume in 1 s, mean forced expiratory flow measured between 25% and 75% of vital capacity, and an elevated value of central airway resistance. The authors tested the changes in these variables induced by inhalation of a beta2 agonist. Baseline lung function was altered more significantly in both male and female patients who lived in downtown Marseilles than in those who resided in the suburbs, and the differences persisted regardless of the season during which the study occurred. Prevalence of bronchial hyperreactivity and symptoms of asthma (but not of rhinitis) were higher in the downtown than suburban male subjects. The results of this study suggest that an association exists between actual environmental exposure to outdoor air pollution (i.e., nitrogen oxides and/or particulate matter of 10 millimeters or less) and respiratory effects in sensitive adults represented by patients with chronic obstructive pulmonary disease or asthma.

High prevalence of bronchial hyperresponsiveness and asthma in ice hockey players.

The prevalence of asthma was studied in a ice hockey team compared with both a floor ball team and the Swiss population. Lung function, bronchial hyperresponsiveness to methacholine, asthma symptoms and exercise-induced asthma were measured in a cross-sectional prospective study. A positive response to the methacholine bronchial provocation test was found in 34.6% of the ice hockey players and 20.8% of the floor ball players (Swiss population 16.4%). The provocative dose causing a 20% fall in the forced expiratory volume in one second (PD20) was significantly lower in ice hockey players than in floor ball players, but there was no significant difference in the dose-response slopes between the two groups. Asthma was diagnosed in 19.2% of the ice hockey players and in 4.2% of the floor ball players (Swiss population 6.8%), whereas exercise-induced asthma was found in 11.5% of the ice hockey players and in 4.2% of the floor ball players. In conclusion, asthma and bronchial hyperresponsiveness seemed to be more common in ice hockey players than in floor ball players and in the Swiss population. Strenuous exercise at lower temperatures may be a risk factor for the higher prevalence of asthma and bronchial hyperresponsiveness, as well as the increased severity of bronchial hyperresponsiveness, particularly in ice hockey players.

Asthma and increased bronchial responsiveness in elite athletes: Atopy and sport event as risk factors

Background: High prevalence of bronchial hyperresponsiveness and asthma has been found in cross-country skiers. There is limited evidence that asthma and bronchial responsiveness would be common also in athletes with summer events. Objectives: The objective of this study was to investigate occurrence of and risk factors for increased bronchial responsiveness and asthma in elite athletes with summer events and to compare their results with those of control subjects. Methods: Forty-nine speed and power athletes (mean age 21.1 years, range 16 to 31), 71 long-distance runners (mean age 26.6 years, range 16 to 39), 42 swimmers (mean age 18.6 years, range 14 to 25), and 45 control subjects (mean age 26.7 years, range 21 to 37) were studied. The subjects answered questionnaires and were given a resting spirometric examination, a skin prick test, and a histamine challenge test. Results: Current asthma (current asthmatic symptoms and increased bronchial responsiveness) was observed in 14% (22 of 162) of the athletes and in 2% (1 of 45) of the control subjects ( p = 0.041). Total asthma (current asthmatic symptoms and increased bronchial responsiveness or physician-diagnosed asthma) occurred in 23% (37 of 162) of the athletes and in 4% (2 of 45) of the control subjects ( p = 0.0048). Atopy according to skin prick test results was found in 48% (77 of 162) of the athletes and in 36% (16 of 45) of the control subjects (not significant). Clinical pollen allergy (positive skin test reaction to pollen and symptoms of rhinoconjunctivitis) was significantly ( p = 0.037) more common in athletes than in control subjects. Atopic athletes showed significantly more often increased bronchial responsiveness, current asthma, and total asthma than nonatopic athletes ( p = 0.011, p = 0.0049, and p < 0.0001, respectively), and the odds ratios of increased bronchial responsiveness and asthma increased with the number of positive skin test reactions. After adjustment for confounding factors, the odds ratio for the occurrence of current asthma was 5.49 (95% confidence interval 0.56 to 53.7) in speed and power athletes, 2.88 (0.30 to 27.7) in long-distance runners, and 10.8 (1.10 to 106.0) in swimmers compared with control subjects. The adjusted odds ratios for the occurrence of total asthma were 3.56 (0.62 to 20.5) in speed and power athletes, 6.01 (1.19 to 30.2) in long-distance runners, and 5.89 (1.00 to 34.5) in swimmers. Conclusions: Asthma is more common in highly trained athletes than in control subjects. Asthma is especially common in elite swimmers, but the risk of asthma is increased also in long-distance runners. Increased bronchial responsiveness and asthma are strongly associated with atopic disposition and its severity in elite athletes.(J Allergy Clin Immunol 1998;101:646-52.)

Prevalence of bronchial hyper-responsiveness in the southern, central and northern parts of Sweden

Studies have suggested that there is a higher prevalence of asthma in northern Sweden than in southern Sweden. Bronchial hyper-responsiveness (BHR) has been shown to be associated with asthma. The aim of this study was to explore the prevalence of bronchical hyper-responsiveness in different parts of Sweden. As part of the European Community Respiratory Health Survey (ECRHS), interviews, skin prick tests, lung function tests and methacholine provocation tests of the airways were performed in 1448 randomly selected subjects in southern, central and northern Sweden. The Mefar dosimeter was used according to the ECRHS protocol. The responsiveness was calculated both as the PD 20 and as the dose response slope (DRS). BHR was defined as a PD 20 of ≤ 1·6 mg. Atopy was defined as at least one skin prick test of ≥ 3 mm. The prevalence of BHR was 12·7%, 10·6% in men and 15·0% in women. No difference in prevalence was found between the three different regions of Sweden. The prevalence of BHR was higher in women than in men and higher in smokers than in non-smokers. Using multiple logistic regression, with BHR as the dependent variable, atopy, being female, having a low FEV 1 (% predicted) and smoking (both own and passive) increased the odds of having BHR, while age and the region of Sweden did not influence BHR. Defining BHR as a PD 20 of ≤ 1·0 mg or a PD 20 of ≤ 2·0 mg did not change this. Multiple regression using log DRS as the dependent variable produced the same result. Both BHR and increasing DRS were associated with self-reported wheezing, attacks of shortness of breath during the daytime at rest or after strenuous activity, being awakened by a feeling of tightness in the chest or an attack of shortness of breath. In subjects without self-reported asthma, BHR was associated with self-reported wheezing and attacks of shortness of breath after strenuous activity. In conclusion, we found that the prevalence of BHR in the three investigated areas was 12·7%. We found a trend towards a higher prevalence of BHR in the most northerly of the study areas, but the difference between the areas was not statistically significant. BHR and DRS were associated with atopy, smoking, female sex and FEV 1 (%predicted). The reporting of symptoms from the airways was associated with the degree of bronchical responsiveness.

Prevalence of asthma in young cross-country skiers in central Scandinavia: differences between Norway and Sweden

An increased prevalence of asthma in cross-country skiers has been reported previously. This study was conducted in order to evaluate the prevalence of asthma among young, elite cross-country skiers in Trøndelag, Norway and Jämtland, Sweden. These two regions in central Scandinavia have different climates during the winter season, with a coastal type in Trøndelag while Jämtland is characterized by a colder, drier, inland type of climate. The study population consisted of 171 skiers (118 from Norway, 53 from Sweden). The investigation included an asthma questionnaire, spirometry and methacholine provocation testing. The prevalence of self-reported asthma-related symptoms was 46% in Norway and 51% in Sweden. The prevalence of bronchial hyper-responsiveness (BHR) was significantly different between the two regions. In Norway, 14% of the skiers were hyper-responsive to methacholine compared to 43% in Sweden ( P < 0·001). Moreover, the estimated prevalence of clinically diagnosed asthma was 12% in Norway and 42% in Sweden ( P < 0·001). The self-reported frequency of respiratory allergy was higher in Sweden (32%) than in Norway (11%). However, on an individual basis, self-reported allergy did not predict occurrence of asthma or BHR. In conclusion, there is a high prevalence of BHR and asthma among young, elite cross-country skiers in central Scandinavia, especially in Sweden. Cross-country skiing may be a risk factor for the development of asthma. Longitudinal studies of cross-country skiers, and studies to acquire further knowledge of the mechanisms involved in the development of asthma are indicated.

Assessment of chlorine exposure in swimmers during training.

The presence of a high prevalence of bronchial hyperresponsiveness and asthma-like symptoms in swimmers has been recently reported. Chlorine, a strong oxidizing agent, is an important toxic gas that the swimmer can breath during swimming. Measurements of the chlorine concentration at the breathing level (< 10 cm) were obtained randomly during five nonconsecutive days in four different swimming pool enclosures. The mean level in all the swimming pools was 0.42 +/- 0.24 mg.m-3, far below the threshold limited value (TLV) of 1.45 mg.m-3 for the work places for a day of work (8 h). The TLV could be reached and even exceeded if we consider the total amount of chlorine that a swimmer inhales in a daily training session of 2 h (4-6 g) compared with a worker during 8 h at the TLV (4-7 g). Low correlation was observed with the number of swimmers in the swimming pool during the measurements (0.446) and other variables as the water surface area of the pool, volume of the enclosure, and the chlorine-addition system in the swimming pool. A low turnover rate in the air with an increase of chlorine levels through the day (P < 0.05) was observed in all pools. The concentration of chlorine in the microenvironment where the swimmer is breathing is below the TLV concentration limit, but nevertheless results in a high total volume of chlorine inhaled by the swimmers in a given practice session. The possible role of chlorine in producing respiratory symptoms in swimmers needs further investigation.