Prevalence of asthma and atopy in two areas of West and East Germany

The German reunification offers a unique opportunity to study the impact of environmental factors on the development of childhood respiratory and allergic disorders in ethnically similar populations. We investigated the prevalence of asthma, hay fever, atopy, and bronchial hyperresponsiveness (BHR) in 9- to 11-year old children in West Germany (n = 5,030) and East Germany (n = 2,623). A self-administered questionnaire was distributed to the parents. Children underwent cold air challenge and allergy skin prick tests. Atopic sensitization was considerably more frequent in West German children than in their peers in East Germany (36.7% versus 18.2%; odds ratio [OR] = 2.6, p < 0.0001). The prevalence of current asthma and hay fever was significantly higher in West Germany when compared with that in East Germany (5.9% versus 3.9%; OR = 1.5, p < 0.0001 and 8.6% versus 2.7%; OR = 3.4, p < 0.0001, respectively). Bronchitis, however, was more prevalent in East Germany than in the western part of the country. The prevalence of BHR as assessed by cold air challenge was higher in West Germany compared with that in East Germany (8.3% versus 5.5%, OR = 1.6, p < 0.001). Logistic regression showed that the West German study area was no longer a significant independent determinant of asthma once sensitization to mites, cats, and pollen was taken into account. We conclude that sensitization to aeroallergens is strikingly more frequent in West Germany than in East Germany and this may explain the differences in the prevalence of asthma and hay fever between the two parts of the country.

Lung function and respiratory symptoms at 11 years in children born extremely preterm: the EPICure study

RATIONALE

The long-term respiratory sequelae of infants born extremely preterm (EP) and now graduating from neonatal intensive care remains uncertain.

OBJECTIVES

To assess the degree of respiratory morbidity and functional impairment at 11 years in children born EP (i.e., at or less than 25 completed weeks of gestation) in relation to neonatal determinants and current clinical status.

METHODS

Pre- and postbronchodilator spirometry were undertaken at school in children born EP and classroom control subjects. Physical examination and respiratory health questionnaires were completed. Multivariable regression was used to estimate the predictive power of potential determinants of lung function.

MEASUREMENTS AND MAIN RESULTS

Spirometry was obtained in 182 of 219 children born EP (129 with prior bronchopulmonary dysplasia [BPD]) and 161 of 169 classmates, matched for age, sex, and ethnic group. Children born EP had significantly more chest deformities and respiratory symptoms than classmates, with twice as many (25 vs. 13%; P < 0.01) having a current diagnosis of asthma. Baseline spirometry was significantly reduced (P < 0.001) and bronchodilator responsiveness was increased in those born EP, the changes being most marked in those with prior BPD. EP birth, BPD, current symptoms, and treatment with beta-agonists are each associated independently with lung function z-scores (adjusted for age, sex, and height) at 11 years. Fifty-six percent of children born EP had abnormal baseline spirometry and 27% had a positive bronchodilator response, but less than half of those with impaired lung function were receiving any medication.

CONCLUSIONS

After extremely preterm birth, impaired lung function and increased respiratory morbidity persist into middle childhood, especially among those with BPD. Many of these children may not be receiving appropriate treatment.

Changing prevalence of asthma in Australian children

OBJECTIVE

To investigate whether prevalence of asthma in children increased in 10 years.

DESIGN

Serial cross sectional studies of two populations of children by means of standard protocol.

SETTING

Two towns in New South Wales: Belmont (coastal and humid) and Wagga Wagga (inland and dry).

SUBJECTS

Children aged 8-10 years: 718 in Belmont and 769 in Wagga Wagga in 1982; 873 in Belmont and 795 in Wagga Wagga in 1992.

MAIN OUTCOME MEASURES

History of respiratory illness recorded by parents in self administered questionnaire; airway hyperresponsiveness by histamine inhalation test; atopy by skin prick tests; counts of house dust mites in domestic dust.

RESULTS

Prevalence of wheeze in previous 12 months increased in Belmont, from 10.4% (75/718) in 1982 to 27.6% (240/873) in 1992 (P < 0.001), and in Wagga Wagga, from 15.5% (119/769) to 23.1% (183/795) (P < 0.001). The prevalence of airway hyperresponsiveness increased twofold in Belmont to 19.8% (173/873) (P < 0.001) and 1.4-fold in Wagga Wagga to 18.1% (P < 0.05). The prevalence of airway hyperresponsiveness increased mainly in atopic children only, but the prevalence of atopy was unchanged (about 28.5% in Belmont and about 32.5% in Wagga Wagga). Numbers of house dust mites increased 5.5-fold in Belmont and 4.5-fold in Wagga Wagga.

CONCLUSIONS

We suggest that exposure to higher allergen levels has increased airway abnormalities in atopic children or that mechanisms that protected airways of earlier generations of children have been altered by new environmental factors.

Cough and bronchial responsiveness in firefighters at the World Trade Center site

BACKGROUND

Workers from the Fire Department of New York City were exposed to a variety of inhaled materials during and after the collapse of the World Trade Center. We evaluated clinical features in a series of 332 firefighters in whom severe cough developed after exposure and the prevalence and severity of bronchial hyperreactivity in firefighters without severe cough classified according to the level of exposure.

METHODS

"World Trade Center cough" was defined as a persistent cough that developed after exposure to the site and was accompanied by respiratory symptoms severe enough to require medical leave for at least four weeks. Evaluation of exposed firefighters included completion of a standard questionnaire, spirometry, airway-responsiveness testing, and chest imaging.

RESULTS

In the first six months after September 11, 2001, World Trade Center cough occurred in 128 of 1636 firefighters with a high level of exposure (8 percent), 187 of 6958 with a moderate level of exposure (3 percent), and 17 of 1320 with a low level of exposure (1 percent). In addition, 95 percent had symptoms of dyspnea, 87 percent had gastroesophageal reflux disease, and 54 percent had nasal congestion. Of those tested before treatment of World Trade Center cough, 63 percent of firefighters (149 of 237) had a response to a bronchodilator and 24 percent (9 of 37) had bronchial hyperreactivity. Chest radiographs were unchanged from precollapse findings in 319 of the 332 with World Trade Center cough. Among the cohort without severe cough, bronchial hyperreactivity was present in 77 firefighters with a high level of exposure (23 percent) and 26 with a moderate level of exposure (8 percent).

CONCLUSIONS

Intense, short-term exposure to materials generated during the collapse of the World Trade Center was associated with bronchial responsiveness and the development of cough. Clinical and physiological severity was related to the intensity of exposure.

Prevalence of asthma and allergic disorders among children in united Germany: a descriptive comparison

OBJECTIVES

To compare the prevalence of asthma and allergic disorders among children in Munich, western Germany, and Leipzig, eastern Germany, where environmental exposure, particularly air concentrations of sulphur dioxide and particulate matter, and living conditions have differed over the past 45 years.

DESIGN

Prevalence surveys among school-children aged 9-11 years in Leipzig and Munich. Self completion of written questionnaire by the children's parents and lung function measurements.

SUBJECTS

1051 children in Leipzig and 5030 in Munich.

SETTING

Primary schools.

MAIN OUTCOME MEASURES

Reported lifetime prevalence of asthma and allergic disorders, and bronchial hyperresponsiveness assessed by cold air inhalation challenge.

RESULTS

The lifetime prevalence of asthma diagnosed by a doctor was 7.3% (72) in Leipzig and 9.3% (435) in Munich; prevalence of wheezing were 20% (191) and 17% (786) respectively. The prevalence of diagnosed bronchitis was higher in Leipzig than Munich (30.9% (303) v 15.9% (739); p < 0.01). A significant drop in forced expiratory volume (> 9%) after cold air challenge was measured in 6.4% (57) of children in Leipzig and in 7.7% (345) of those in Munich. Hay fever (2.4% (24) v 8.6% (410); p < 0.01) and typical symptoms of rhinitis (16.6% (171) v 19.7% (961); p < 0.05) were reported less often in Leipzig than in Munich.

CONCLUSIONS

No significant differences were seen in the lifetime prevalence of asthma, wheezing, and bronchial hyperresponsiveness between children in Leipzig and Munich. The lifetime prevalence of bronchitis was higher in Leipzig than in Munich. The lower prevalence rates of allergic disorders in Leipzig could point toward aetiological factors that are associated with Western lifestyle and living conditions.

The European Community Respiratory Health Survey: what are the main results so far? European Community Respiratory Health Survey II

The European Community Respiratory Health Survey (ECRHS) was the first study to assess the geographical variation in asthma and allergy in adults using the same instruments and definitions. The database of the ECRHS includes information from approximately 140,000 individuals from 22 countries. The aim of this review is to summarize the results of the ECRHS to date. The ECRHS has shown that there are large geographical differences in the prevalence of asthma, atopy and bronchial responsiveness, with high prevalence rates in English speaking countries and low prevalence rates in the Mediterranean region and Eastern Europe. Analyses of risk factors have highlighted the importance of occupational exposure for asthma in adulthood. The association between sensitization to individual allergens and bronchial responsiveness was strongest for indoor allergens (mite and cat). Analysis of treatment practices has confirmed that the treatment of asthma varies widely between countries and that asthma is often undertreated. In conclusion, the European Community Respiratory Health Survey has shown that the prevalence of asthma varies widely. The fact that the geographical pattern is consistent with the distribution of atopy and bronchial responsiveness supports the conclusion that the geographical variations in the prevalence of asthma are true and most likely due to environmental factors.

Treatment of allergic rhinitis with intranasal corticosteroids in patients with mild asthma: effect on lower airway responsiveness

The effect of treatment of allergic rhinitis with intranasal corticosteroids on lower airway responsiveness was assessed in a randomized, double-blind, placebo-controlled, crossover study. Twenty-one young patients with perennial allergic rhinitis and asthma, with documented lower airway hyperresponsiveness (PC20 methacholine < 8 mg/ml), were treated with intranasal aqueous beclomethasone dipropionate and placebo, each given for 4 weeks. Patients recorded rhinitis and asthma symptom scores and monitored peak expiratory flow rates every morning and evening. Patients recorded global assessment of rhinitis and global asthma symptom scores at the beginning and end of each treatment. PC20 methacholine was performed at baseline and at the end of each treatment period. Intranasal beclomethasone dipropionate significantly reduced global rhinitis symptom scores (p = 0.05) after 4 weeks of treatment. Global asthma scores did not change significantly (p = 0.2). Geometric mean PC20 methacholine improved significantly after 4 weeks of intranasal beclomethasone, but not after placebo (p = 0.04). Daily morning and evening rhinitis symptom scores were lower in patients treated with intranasal corticosteroids over the first 4 weeks of treatment, but carryover effect of steroids precluded comparative analysis of the second 4-week block (morning p = 0.06, evening p = 0.03). Morning asthma scores tended to decrease (p = 0.07). Evening asthma scores were significantly decreased at weeks 2 and 3 (p = 0.001, p = 0.02, respectively). No change in peak expiratory flow rate was seen. This study confirms that treatment of inflammation in the upper airways indirectly improves asthma symptoms and decreases bronchial hyperreactivity. Ignoring inflammation in the upper airway may lead to suboptimal results in asthma treatment.

Association between asthma and rhinitis according to atopic sensitization in a population-based study

BACKGROUND

Although asthma and rhinitis often occur together, the reason for this common comorbidity is still a matter of debate.

OBJECTIVE

We sought to assess whether the coexistence of asthma and rhinitis could be explained by common risk factors.

METHODS

International cross-sectional study of representative samples of young adults, who completed a detailed questionnaire and underwent lung function tests, bronchoprovocation challenge, IgE measurements, and skin prick tests.

RESULTS

In all countries, asthma and bronchial hyperreactivity were more frequent in subjects with rhinitis than in those without (odds ratio [OR], 6.63; 95% CI, 5.44-8.08; and OR, 3.02 95% CI, 2.66-3.43, respectively). Seventy-four percent to 81% of subjects with asthma reported rhinitis, depending on sensitization to specific allergens. Conversely, the risk of asthma increased from 2.0% in subjects without rhinitis to 6.7% in subjects with rhinitis only when exposed to pollen, 11.9% in subjects with rhinitis when exposed to animals, and 18.8% in subjects with rhinitis either when exposed to pollen or to animals. The association between rhinitis and asthma remained significant after adjustment for total IgE, parental history of asthma, and allergen sensitization (OR, 3.41; 95% CI, 2.75-4.2 suggesting that the coexistence of asthma and rhinitis is not solely due to atopic predisposition to these 2 diseases.

CONCLUSIONS

Although there were some variations in the association between asthma and rhinitis according to sensitization to individual allergens, the strong association between asthma and rhinitis was not fully explained by shared risk factors, including atopy. Our findings are consistent with the hypothesis that rhinitis might increase the risk of asthma.

Exercise-induced asthma, respiratory and allergic disorders in elite athletes: epidemiology, mechanisms and diagnosis: part I of the report from the Joint Task Force of the European Respiratory Society (ERS) and the European Academy of Allergy and Clinical Immunology (EAACI) in cooperation with GA2LEN

AIMS

To analyze the changes in the prevalence of asthma, bronchial hyperresponsiveness (BHR) and allergies in elite athletes over the past years, to review the specific pathogenetic features of these conditions and to make recommendations for their diagnosis.

METHODS

The Task Force reviewed present literature by searching Medline up to November 2006 for relevant papers by the search words: asthma, bronchial responsiveness, EIB, athletes and sports. Sign criteria were used to assess level of evidence and grades of recommendation.

RESULTS

The problems of sports-related asthma and allergy are outlined. Epidemiological evidence for an increased prevalence of asthma and BHR among competitive athletes, especially in endurance sports, is provided. The mechanisms for development of asthma and bronchial hyperresponsiveness in athletes are outlined. Criteria are given for the diagnosis of asthma and exercise induced asthma in the athlete.

CONCLUSIONS

The prevalence of asthma and bronchial hyperresponsiveness is markedly increased in athletes, especially within endurance sports. Environmental factors often contribute. Recommendations for the diagnosis of asthma in athletes are outlined.

Toward a definition of asthma for epidemiology

Because there is no "gold standard" for defining asthma for epidemiology, we have defined current asthma as bronchial hyperresponsiveness (BHR) plus recent wheeze (in the 12 months prior to study). To describe the characteristics of groups categorized by these measurements, we studied two samples of children aged 7 to 12 yr: 210 from a population sample and 142 self-identified asthmatics. Bronchial responsiveness to histamine was measured by the rapid method, respiratory symptom history, and asthma medication use by self-administered questionnaire to parents and atopy by skin prick tests to 14 allergens. Children recorded daily Airflometer readings and symptom scores for 2 wk. Children with current asthma had more severe bronchial responsiveness, greater Airflometer variability, more symptoms, more atopy (particularly to house dust mites), and used more asthma medication than children with BHR or recent wheeze alone. Children with BHR, but not with recent wheeze, were intermediate between the current asthma and normal groups in terms of bronchial responsiveness, Airflometer variability, and atopy. Children with recent wheeze and normal responsiveness differed from the normal group only in symptoms and medication use. Our definition of current asthma discriminates a group of children that is clearly different in terms of both clinical features and physiologic measures. As such, it is the most useful definition to date for measuring the prevalence of clinically important asthma in populations.

Prevalence of respiratory and atopic disorders among children in the East and West of Germany five years after unification

Living conditions in eastern Germany have changed rapidly since unification in 1990 and little is known about how these changes affect the prevalence of atopic diseases. This study describes methods and prevalences of a large epidemiological project investigating determinants of childhood asthma and allergies in eastern (Dresden and Leipzig) and western (Munich) Germany in 1995/1996. Community based random samples of 9-11 yr old children in Dresden (n=3,017) and Munich (n=2,612), and of 5-7 yr old children in Dresden (n=3,300), Leipzig (n=3,167) and Munich (n=2,165) were studied by parental questionnaires, bronchial challenges with hypertonic saline, skin examination, skin-prick tests, and measurements of specific and total serum immunoglobulin (Ig)E using Phase II modules of the International Study of Asthma and Allergies in Childhood (ISAAC). In 9-11 yr old children, the prevalence of physician diagnosed asthma (7.9% versus 10.3%; p<0.01) and bronchial hyperresponsiveness (15.7% versus 19.9%; p<0.05) was lower in Dresden than in Munich. No difference between Munich and Dresden was observed in the prevalence of diagnosed hay fever, skin test reactivity to > or = 1 allergen, and increased levels (>0.35 kU x L(-1)) of specific IgE against inhalant and food allergens. Symptoms and visible signs of atopic eczema tended to be more prevalent in Dresden. Similar East-West differences between the three study areas were seen in the younger age group. These findings are in line with recently observed increases in the prevalence of hay fever and atopic sensitization, but not of asthma and bronchial hyperresponsiveness, among 9-11 yr old children in Leipzig.

Nitric oxide synthesis inhibitors induce airway hyperresponsiveness in the guinea pig in vivo and in vitro. Role of the epithelium

The administration by aerosol of the nitric oxide (NO) synthesis inhibitors, N omega-nitro-L-arginine methyl ester (L-NAME) or Ng-monomethyl-L-arginine (L-NMMA), to spontaneously breathing anesthetized guinea pigs resulted in a significant enhancement of lung resistance (RL) after increasing intravenous doses of histamine. The maximal response was increased (p < 0.01) by 126% (L-NAME) and 282% (L-NMMA) compared with the control groups. This effect was inhibited by giving an aerosol of the NO precursor L-arginine (L-Arg) but not by its inactive enantiomer D-arginine (D-Arg). Perfusion through the lumen of guinea pig tracheal tubes in vitro with nitric oxide synthesis inhibitors (120 microM) resulted in a significant increase in basal tone, suggesting a role for NO in the maintenance of basal tone. In addition, the histamine concentration-response curve was significantly shifted upward: the maximal response was increased (p < 0.01) by 335% (L-NAME) and 250% (L-NMMA) compared with the control group. This effect was concentration dependently inhibited by coincubation with L-Arg (120, 200, and 400 microM), but not with D-Arg (200 microM). Furthermore, removal of the epithelium resulted in an upward shift in the histamine concentration-response curve: the maximal response was increased by 185%. However, incubation with L-NAME did not further increase tracheal responsiveness to histamine, but addition of L-Arg (360 microM), when a plateau was reached, relaxed the tissues to control values. Nitric oxide synthesis inhibition did not change the responsiveness of intact tissues in vitro after intraluminal stimulation with leukotriene D4, serotonin, or the cholinergic agonist arecoline.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of anti-IL-5 and IL-5 on airway hyperreactivity and eosinophils in guinea pigs

Chronic ovalbumin challenge of sensitized guinea pigs induces bronchoalveolar lavage (BAL) eosinophilia, neutrophilia, and tracheal hyperreactivity. In the present study, the influence of monoclonal antibody to murine interleukin-5 (anti-IL-5) on these phenomena is examined. In ovalbumin-sensitized guinea pigs treated with isotype-matched control antibody and challenged daily with ovalbumin for 8 days, the number of BAL eosinophils and neutrophils is increased significantly six- and fivefold, respectively, compared with saline-challenged animals. The maximal contractions of tracheal rings to histamine and arecoline in ovalbumin-challenged animals are enhanced significantly to 155% compared with saline-challenged animals. In sensitized guinea pigs treated with anti-IL-5, the BAL eosinophil number is markedly inhibited compared with control antibody treatment in both saline- and ovalbumin-challenged animals. In contrast, the number of neutrophils is not affected by anti-IL-5 treatment. In guinea pigs treated with anti-IL-5, the development of hyperreactivity to histamine and arecoline after ovalbumin challenge is completely inhibited. The contractions to histamine and arecoline of tracheal rings isolated from guinea pigs treated with recombinant murine IL-5 for 3 or 7 days are enhanced significantly to approximately 140% compared with controls. Treatment with IL-5 for 7 days tends to increase the number of eosinophils in BAL fluid. It can be concluded that IL-5 is involved in airway eosinophilia and in the development of hyperreactivity in this animal model, but other cytokines may contribute. Development of IL-5 synthesis inhibitors and/or receptor antagonists could provide another therapeutic class of anti-asthma drugs.

Defining asthma in epidemiological studies

It has been suggested that, in epidemiological studies, asthma should be defined as symptomatic bronchial hyperresponsiveness (BHR). This paper critically examines the validity of this and alternative methods of defining asthma by reviewing population-based studies validating BHR and symptom questionnaires against asthma defined on the basis of a clinical assessment. It is emphasized that a single definition of asthma will not be applicable to all studies. When the aim of a study is to compare differences in prevalence of asthma between populations, Youden's Index (sensitivity + specificity - 1) is the best single measure of validity. BHR has similar or better specificity, but much worse sensitivity, and therefore a worse Youden's Index, than symptom questionnaires. When the aim is to estimate relative risks, the validity of the definition of asthma depends more on its positive predictive value. Therefore, more specific methods of detecting asthmatics, such as severe symptoms, diagnoses of asthma, or symptomatic BHR may be most useful in cohort and case-control studies. In contrast, conversely, the method of choice for the first phase of prevalence comparisons is standardized written or video symptom questionnaires. In order to explore reasons for the differences in asthma prevalence, and to estimate possible differential symptom reporting, questionnaires can be supplemented with bronchial hyperresponsiveness and other testing in subsamples of the symptomatic and nonsymptomatic subjects. However, symptoms and bronchial hyperresponsiveness should usually be analysed separately rather than combined due to the poor agreement between bronchial hyperresponsiveness and clinical asthma.

Association between body mass index and allergy in teenage girls in Taiwan

BACKGROUND

The prevalence of atopy and asthma is affected by age, sex and lifestyle factors. Obesity was reported to be a risk factor for asthmatic symptoms in children and adults.

OBJECTIVE

To examine the relation between body mass index (BMI) and the prevalence of atopy, rhinitis, wheezing and bronchial responsiveness in adolescents.

METHODS

BMI (kg/m2), skin-prick test, bronchial hyperresponsiveness (BHR) to methacholine, and self-reported rhinitis and airway symptoms were assessed in a cross-sectional survey in 1459 eighth-grade students (age 13.2 to 15.5, mean 13.6 years) of seven junior high schools in northern Taiwan.

RESULTS

The prevalence of atopy was 42% in boys and 27% in girls. The study population was grouped into quintiles of BMI by sex. Girls in the highest BMI quintile had higher prevalence of atopy and rhinitis symptoms. Compared with the middle three quintiles, they had increased risk of atopy in multivariate analyses adjusted for area of living, sibling number, parent education level and family history of asthma (odds ratio = 1.77, 95% confidence interval = 1.15-2.73). Girls with the lowest BMI quintile had lower prevalence of BHR and wheezing. Compared with the middle three quintiles, they had reduced risk of BHR in multivariate analyses adjusted for area of living, atopy, family history of asthma, and baseline pulmonary function (odds ratio = 0.40, 95% confidence interval = 0.20-0.81). No association between BMI and atopy or BHR was seen in boys.

CONCLUSION

BMI was a significant predictor of atopy, allergic symptoms and BHR in teenage girls.

Importance of house dust mite and Alternaria allergens in childhood asthma: an epidemiological study in two climatic regions of Australia

The relation of house dust mite allergen levels to asthma and allergy was examined in two population samples of children aged 8-11 years in northern New South Wales. We studied 805 children in Lismore (a hot, humid, coastal region) and 770 in Moree/Narrabri (a hot, dry inland region). Respiratory symptoms were measured by questionnaire, bronchial hyperresponsiveness (BHR) by histamine inhalation test, and allergy by skin-prick tests. Current asthma was defined as the presence of both wheeze in last 12 months and BHR. Der p I levels were measured in dust from the bed and floors in the homes of 57 randomly selected children in the coastal region and of 74 inland children. Der p I levels were significantly higher by the coast (83.0 vs 11.2 microg/g, P < 0.001). House dust mite sensitivity was of similar prevalence in both regions (28.6 vs 26.4%, n.s.) but Alternaria sensitivity was higher inland (4.0 vs 15.2% P<0.001). Bronchial responsiveness was more severe in coastal children sensitized to house dust mites and in inland children who were sensitized to Alternaria. The adjusted odds ratios for current asthma in children sensitized to house dust mites were 21.3 (95% CI 10.5, 43.2) by the coast and 2.7 (95% CI 1.3, 5.4) inland, and in children sensitized to Alternaria were 3.4 (95% CI 1.3, 9.1) in the coastal region and 5.6 (95% CI 3.1, 10.1 inland. These studies suggest that high house dust mite allergen levels in a humid, subtropical region act to significantly increase bronchial responsiveness in sensitized children, and that Alternaria allergens have a similar but less potent action in a dry, rural region.

Prevalence of respiratory symptoms, bronchial hyperresponsiveness and atopy among adults: west and east Germany

The prevalence of respiratory symptoms, atopic sensitization and bronchial hyperresponsiveness was compared in a random sample of adults, 20-44 yrs of age, in two cities in West and East Germany, Hamburg and Erfurt, respectively. There were much higher levels of outdoor air pollution due to sulphur dioxide and suspended particulates in Erfurt, and major differences in living conditions during the last 40 yrs. Within the European Respiratory Health Survey, a short questionnaire was answered by 3,156 (80% response rate) subjects in Hamburg and 3,272 (74%) in Erfurt. A subset of responders to the short questionnaire completed a long questionnaire, spirometry, methacholine or bronchodilator test, skin test, and total and specific immunoglobulin E (IgE) measurements, with a total number of 1,159 participants in Hamburg and 731 in Erfurt. Six out of 8 questions on respiratory symptoms and diagnoses were answered in the affirmative more frequently in Hamburg than in Erfurt. In Hamburg, mean forced expiratory volume in one second (FEV1)% of predicted was 105 vs 107% in Erfurt (p < 0.0001), and bronchial hyperresponsiveness was more frequently observed in Hamburg than in Erfurt (25 vs 19%; p < 0.05). Atopic sensitization was more prevalent in Hamburg than in Erfurt regarding the results of skin tests against grass pollen (24 vs 19%; p < 0.05), birch pollen (19 vs 8%; p < 0.0005), cat (10 vs 2%; p < 0.0005), and Dermatophagoides pteronyssinus (14 vs 10%; p < 0.05). This was reflected by the prevalences of positive specific IgE values, which were higher in Hamburg than in Erfurt for grass (26 vs 20%; p < 0.05), birch (20 vs 10%; p < 0.0005) and cat (12 vs 8%; p < 0.05). In Hamburg, compared to Erfurt, there was: a lower mean number of siblings (p < 0.005); a higher degree of childhood and current exposure to environmental tobacco smoke (p < 0.005); and a higher frequency of fitted carpets and reported mould or mildew inside the house (p < 0.005). Therefore, these data may support the hypothesis that childhood factors and exposure to indoor allergens and irritants may have been more relevant for the development of asthma and atopy than the potential long-term exposure to high concentrations of sulphur dioxide and particulate matter.

Asthma and atopy in overweight children

BACKGROUND

Obesity may be associated with an increase in asthma and atopy in children. If so, the effect could be due to an effect of obesity on lung volume and thus airway hyperresponsiveness.

METHODS

Data from 5993 caucasian children aged 7-12 years from seven epidemiological studies performed in NSW were analysed. Subjects were included if data were available for height, weight, age, skin prick test results to a common panel of aeroallergens, and a measure of airway responsiveness. History of doctor diagnosed asthma, wheeze, cough, and medication use was obtained by questionnaire. Recent asthma was defined as a doctor diagnosis of asthma ever and wheeze in the last 12 months. Body mass index (BMI) percentiles, divided into quintiles per year age, were used as a measure of standardised weight. Dose response ratio (DRR) was used as a measure of airway responsiveness. Airway hyperresponsiveness was defined as a DRR of >/=8.1. Adjusted odds ratios were obtained by logistic regression.

RESULTS

After adjusting for atopy, sex, age, smoking and family history, BMI was a significant risk factor for wheeze ever (OR = 1.06, p = 0.007) and cough (OR = 1.08, p = 0.001), but not for recent asthma (OR = 1.02, p = 0.43) or airway hyperresponsiveness (OR = 0.97 p = 0.17). In girls a higher BMI was significantly associated with higher prevalence of atopy (chi(2) trend 7.9, p = 0.005), wheeze ever (chi(2) trend 10.4, p = 0.001), and cough (chi(2) trend 12.3, p<0.001). These were not significant in boys.

CONCLUSIONS

Higher BMI is a risk factor for atopy, wheeze ever, and cough in girls only. Higher BMI is not a risk factor for asthma or airway hyperresponsiveness in either boys or girls.

Irritable bowel syndrome, gastro-oesophageal reflux, and bronchial hyper-responsiveness in the general population

BACKGROUND

Associations have been shown between irritable bowel syndrome (IBS) and gastro-oesophageal reflux, between gastro-oesophageal reflux and asthma, and more recently between IBS and bronchial hyper-responsiveness (BHR).

AIMS

To explore the inter-relations between these conditions.

SUBJECTS

A randomly selected community sample of 4432 adults.

METHODS

A validated postal symptom questionnaire investigating the associations between IBS, gastro-oesophageal reflux symptoms, and symptomatic BHR.

RESULTS

3169 questionnaires (71.7% response) returned by 1451 men and 1718 women were analysed. One year prevalences, in men and women respectively, of IBS were 10.5% and 22.9%, of dyspepsia 26.3% and 25. 25%, of gastro-oesophageal reflux symptoms 29.4% and 28.2%, of BHR 13.2% and 14.6%, and of chronic bronchitis 8.3% and 4.9%. Logistic regression showed independent associations between IBS and BHR, gastro-oesophageal reflux symptoms, and dyspepsia. There was no significant independent association between IBS and chronic bronchitis. In men and women the odds ratio with 95% confidence interval (CI) for IBS and gastro-oesophageal reflux symptoms was 2.6 (2.1-3.1; p<0.001) and for IBS and BHR 2.1 (1.7-2.7; p<0.001). These associations held on stratifying for sex and consultation behaviour. IBS, gastro-oesophageal reflux symptoms, and bronchial hyper-responsiveness occurred more frequently together than expected, 2.5% (95% CI 2.41-2.57) of the sample having all three conditions compared with an expected prevalence of 0.7% (95% CI 0.66-0.71). The conditions were independently associated with each other.

CONCLUSIONS

These observations may indicate the presence of an underlying disorder producing symptoms in gastrointestinal and respiratory systems.

Persistent hyperreactivity and reactive airway dysfunction in firefighters at the World Trade Center

New York City Fire Department rescue workers experienced massive exposure to airborne particulates at the World Trade Center site. Aims of this longitudinal study were to (1) determine if bronchial hyperreactivity was present, persistent, and independently associated with exposure intensity, (2) identify objective measures shortly after the collapse that would predict persistent hyperreactivity and a diagnosis of reactive airways dysfunction 6 months post-collapse. A representative sample of 179 rescue workers stratified by exposure intensity (high, moderate, and control) without current smoking or prior respiratory disease was enrolled. Highly exposed workers arrived within 2 hours of collapse, moderately exposed workers arrived later on Days 1-2; control subjects were not exposed. Hyperreactivity at 1, 3, and 6 months post-collapse was associated with exposure intensity, independent of ex-smoking and airflow obstruction. Six months post-collapse, highly exposed workers were 6.8 times more likely than moderately exposed workers and control subjects to be hyperreactive (95% confidence interval, 1.8-25.2; p = 0.004), and hyperreactivity persisted in 55% of those hyperreactive at 1 and/or 3 months. In highly exposed subjects, hyperreactivity 1 or 3 months post-collapse was the sole predictor for reactive airways dysfunction (p = 0.021). In conclusion, development and persistence of hyperreactivity and reactive airways dysfunction were strongly and independently associated with exposure intensity. Hyperreactivity shortly post-collapse predicted reactive airways dysfunction at 6 months in highly exposed workers; this has important implications for disaster management.

Effective allergen avoidance at high altitude reduces allergen-induced bronchial hyperresponsiveness

We studied the effects of reduced allergen exposure on bronchial hypereactivity (BHR) in two groups of asthmatic children allergic to house dust mites (HDM) living at high altitude for 9 continuous mo. In the first group the serum levels of total and HDM-specific IgE showed significant decreases after 3 mo (p < 0.001 and p < 0.02, respectively) and after 9 mo (p < 0.001). Three months after returning home the total IgE levels had increased significantly (p < 0.001). The mean percentage fall in peak expiratory flow after exercise testing improved after 3 and 9 mo (p < 0.05), but it had deteriorated after 3 mo at home (p < 0.01). The methacholine PD20-FEV1 increased after 3 mo (p = 0.001) and further after 9 mo (p < 0.001), with a decrease after the 3-mo period at sea level (p = 0.01). In the second cohort there was a significant increase in HDM PD20-FEV1 after 6 and 9 mo (p < 0.001), with a slight decrease of magnitude of the allergen-induced late reaction. Histamine PD20-FEV1 significantly increased after 6 and 9 mo at high altitude, particularly in the challenges performed after the HDM bronchial provocation (p < 0.01). Our data demonstrate that allergen avoidance in asthmatic children not only decreases nonspecific BHR but also decreases allergen sensitivity, late allergen-induced bronchial reactions, and enhancement of BHR by allergen challenge.

Relationships between duration of asthma and asthma severity among children in the Childhood Asthma Management Program (CAMP)

BACKGROUND

Many factors, including heredity, atopic status, and environment, have been implicated in the determination of asthma severity. Relatively little is known about the degree to which asthma duration influences asthma severity.

OBJECTIVE

The Childhood Asthma Management Program (CAMP), consisting of 1041 children (age 8. 9 +/- 2.1 years at enrollment) with mild-to-moderate asthma, offers an opportunity to examine the relationship between asthma duration and asthma severity.

METHODS

By using the extensive CAMP baseline cross-sectional data on asthma duration, spirometry, bronchial responsiveness, symptomatology, and markers of atopy, univariate and multivariate regression models were used to evaluate whether asthma duration is associated with asthma severity.

RESULTS

Duration of asthma in the study cohort from time of diagnosis until randomization into CAMP ranged from 0.3 to 12.1 years (mean, 5.0; SD, 2.7; median, 4.8). Asthma duration is associated in univariate analyses both with lower levels of several lung functions (P <.001), including methacholine bronchial reactivity (natural log [ln] FEV1 PC20, mg/mL; r = -0.112), prebronchodilator and postbronchodilator percent predicted FEV1 (r = -0.176 and r = -0.130, respectively), and prebronchodilator and postbronchodilator FEV1 /forced vital capacity (FVC) (%) (r = -0.237 and r = -0.211, respectively), as well as higher levels of symptoms (symptom score: r = 0.147, P <. 001) and borderline greater use of albuterol for symptoms (r = 0.058, P =.064) during a 28-day screening period before randomization. Simple linear regression detected the following differences in lung functions per year of asthma duration: ln FEV1 PC20, -0.050 mg/mL/y; prebronchodilator FEV1, -0.907 percent predicted/y; and prebronchodilator FEV1 /FVC, -0.729 percent predicted/y. After controlling for potential explanatory variables (atopy, inflammatory markers, household Der p 1 levels, anti-inflammatory medication use, and clinical center), regression models revealed that the duration of asthma remained significantly and independently associated with ln FEV1 PC20 (P =.004), prebronchodilator percent predicted FEV1 (P =.043), and prebronchodilator and postbronchodilator FEV1 /FVC (%) (P <.001), as well as being positively associated with mean daily symptom score (P <.001) and albuterol use for symptoms (P =.003) during a 28-day screening period. Duration was also found to be significantly associated with physician/nurse assessment of asthma severity and other historical measures of medication use.

CONCLUSIONS

These data demonstrate that asthma duration is associated with lower lung function, greater methacholine responsiveness, more asthma symptomatology, and greater use of as-needed albuterol, which are all measures of asthma severity. As such, early diagnosis and intervention may be necessary to ameliorate these adverse effects of persistent asthma.

Is bronchial hyperresponsiveness more frequent in women than in men? A population-based study

To test the hypothesis that a greater proportion of women than men react to methacholine challenge and investigate the possible reasons for any differences observed, we recruited 495 subjects 20 to 44 yr of age (50.9% male) in Paris and 304 subjects (51.3% male) in Montpellier (France), as part of the European Community Respiratory Health Survey. The proportion of responders (PD20 < or = 4 mg methacholine) was 33.7% in women and 11.9% in men (odds ratio = 3.8; 95% confidence interval = 2.4-6.0) in Paris and 43.2% in women and 29.5% in men (odds ratio = 1.8; 95% confidence interval = 1.1-2.9) in Montpellier. These differences could not be explained by asthma, respiratory symptoms, atopy, or lung function parameters. In stepwise logistic regressions including sex, asthma, and asthma-like symptoms, nasal allergies, atopy, baseline FEV1, FEV1%pred, FVC, and FEV1%FVC, the odds-ratios for the effect of female sex on PD20 < or = 4 mg methacholine were 5.2 (3.0-9.0) in Paris and 2.2 (1.2-3.8) in Montpellier. Reacting to low doses of methacholine (PD20 < or = 0.5 mg) was associated with asthma and atopy in both men and women. In contrast, reacting to doses between 0.5 and 4 mg was associated with asthma and atopy only in men and with heavy tobacco consumption only in women. We conclude that the excess of hyperresponsiveness in women is not due to their having smaller lung size or airway caliber than men and may be related to a greater susceptibility to smoking.

Inner city air pollution and respiratory health and atopy in children

The impact of inner city air pollution on the development of respiratory and atopic diseases in childhood is still unclear. In a cross sectional study in Dresden, Germany, 5,421 children in two age groups (5-7 yrs and 9-11 yrs) were studied according to the International Study of Asthma and Allergies in Childhood (ISAAC) phase II protocol. The prevalences of wheezing and cough as well as doctor diagnosed asthma and bronchitis were assessed by parental questionnaires. Children also underwent skin-prick testing, venipuncture for the measurement of serum immunoglobulin (Ig)E, lung function testing and a bronchial challenge test (4.5% saline) to assess airway hyperresponsiveness. Exposure was assessed on an individual basis by relating mean annual air pollution levels (SO2, NO2, CO, benzene, and O3) which had been measured on a 1 km2 grid, to the home and school address of each study subject. After adjusting for potential confounding factors an increase in the exposure to benzene of 1 microg x m3 air was associated with an increased prevalence of morning cough (adjusted odds ratio (aOR)): 1.15; 1.04-1.27) and bronchitis (aOR: 1.11; 1.03-1.19). Similar associations were observed for NO2 and CO. In turn, the prevalences of atopic sensitization, symptoms of atopic diseases and bronchial hyperresponsiveness were not positively associated with exposure to any of these pollutants. It is concluded that in this study a moderate increase in exposure to traffic-related air pollution was associated with an increased prevalence of cough and bronchitis, but not with atopic conditions in children.