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

Asthmatic symptoms among pupils in relation to winter indoor and outdoor air pollution in schools in Taiyuan, China

BACKGROUND

There are few studies on associations between children's respiratory heath and air pollution in schools in China. The industrial development and increased traffic may affect the indoor exposure to air pollutants in school environment. Moreover, there is a need to study respiratory effects of environmental tobacco smoke (ETS) and emissions from new building materials in homes in China.

OBJECTIVES

We studied the associations between pupils' asthmatic symptoms and indoor and outdoor air pollution in schools, as well as selected home exposures, in a coal-burning city in north China.

METHODS

A questionnaire survey was administered to pupils (11-15 years of age) in 10 schools in urban Taiyuan, collecting data on respiratory health and selected home environmental factors. Indoor and outdoor school air pollutants and climate factors were measured in winter.

RESULTS

A total of 1,993 pupils (90.2%) participated; 1.8% had cumulative asthma, 8.4% wheezing, 29.8% had daytime attacks of breathlessness. The indoor average concentrations of sulfur dioxide, nitrogen dioxide, ozone, and formaldehyde by class were 264.8, 39.4, 10.1, and 2.3 microg/m3, respectively. Outdoor levels were two to three times higher. Controlling for possible confounders, either wheeze or daytime or nocturnal attacks of breathlessness were positively associated with SO2, NO2, or formaldehyde. In addition, ETS and new furniture at home were risk factors for wheeze, daytime breathlessness, and respiratory infections.

CONCLUSIONS

Indoor chemical air pollutants of mainly outdoor origin could be risk factors for pupils' respiratory symptoms at school, and home exposure to ETS and chemical emissions from new furniture could affect pupils' respiratory health.

Short-term effect of pollen exposure on antiallergic drug consumption

BACKGROUND

Several studies have investigated the association between pollen exposure and asthma emergency admissions, but only 2 have investigated the effect of airborne allergens on consultations for rhinitis or conjunctivitis and none has used drug consumption as the health indicator.

OBJECTIVE

To analyze the short-term association between pollen exposure and antiallergic drug consumption in the urban area of Clermont-Ferrand, France, taking into account the potentially confounding effect of air pollution and meteorological factors.

METHODS

We used the French health insurance database to select all individuals from the Clermont-Ferrand urban area having benefited from reimbursement for antiallergic treatment from January 1, 2000, through December 31, 2001, and from January 1, 2003, through December 31, 2004. An episode of treated allergic rhinitis, rhinosinusitus, or conjunctivitis (ARC) was defined as the association of an oral antihistamine and a local antiallergic drug on the same prescription. The relations between daily changes in pollen concentrations and daily changes in the number of treated ARC cases were analyzed using a Poisson regression model with penalized spline functions.

RESULTS

The risk of treated ARC associated with an interquartile increase in pollen concentration increased significantly for Poaceae (5%, P < .001), Fraxinus (7%, P < .001), Betula (7%, P < .001), and Corylus (2%, P < .02). This increase was significant in all age groups for Poaceae and Fraxinus pollen and in people younger than 65 years for Betula pollen. The effect was mainly concentrated on the present day, except for Poaceae pollens, for which the risk remained significantly (P < .001) increased until 3 days lag time.

CONCLUSIONS

This study showed a significant increase in treated ARC cases related to Poaceae, Fraxinus, and Betula. Specific risks are difficult to evaluate for species that share the same pollination period. Time-series studies based on drug consumption are useful to highlight and to supervise pollen-related diseases requiring ambulatory care.

Burden of asthma in the hospital setting: an Australian analysis

OBJECTIVES

This study was designed to report factors associated with asthma hospital admission, such as patient characteristics, type of admission and subsequent outcome i.e. discharge or death, for the years 2000-2005. These data are used for health economic models regarding asthma burden in the hospital setting in Australia.

METHODS

Data was obtained from the Australian Centre for Asthma Monitoring using their amalgamated dataset from all states and territories. Admissions under ICD-10 codes J45 'Asthma' plus all subcodes, and J46 'acute severe asthma' were included. Codes for associated comorbidity at the time of admission were identified, as well as the month of death, age, gender and length and the type of stay. Confidence intervals for death rate assumed a binomial distribution because of the rarity of event.

RESULTS

The total number of all-cause deaths for the 5-year observation period was 289 from 202,739 asthma separations or 0.14% or 143 deaths/100,000 separations and the highest rate was seen in patients over 45 years. Acute upper respiratory tract infections were reported in up to 25% of all asthma hospital admissions. Length of stay was up to a mean average of 10.2 days in patients who died (SD 15.3). In 5 years observation there was 152,758 emergency asthma admissions which contributed greatly to Australian healthcare burden.

CONCLUSIONS

The study demonstrates that emergency admissions dominate asthma care in the hospital setting in Australia, which suggests poor asthma control in some patients with subsequent economic burden. Asthma-related mortality remains a risk for specific patients in the hospital setting.

Prevalence of asthma among German adults: analysis of the German National Telephone Survey

OBJECTIVE

The purpose of this study was to estimate the prevalence of asthma in German adults.

METHODS

This analysis used data of 8,318 German adults 18 years of age and older who had participated in the German National Telephone Survey, a nationally representative cross-sectional study.

RESULTS

The overall lifetime prevalence of asthma in German adults was 5.7%. It ranges between 4.3% in East and 6.0% in West Germany. Logistic regression analysis showed that asthma was associated with unemployment, younger age, and living in West Germany.

CONCLUSION

This study provides further evidence that differences exist in the prevalence of asthma between East and West Germany.

Associations between ambient PM2.5 concentrations and respiratory symptoms in Melbourne, 1998-2005

Particulate matter (PM) has been widely associated with adverse effects on respiratory health, both overseas and in Australia. This study aimed to investigate the impacts of ambient particles of <2.5 microm diameter (PM2.5) in Melbourne on adverse respiratory symptoms. Two cohorts of adults were recruited in 1992-1998, and completed detailed respiratory questionnaires in 1998-1999 and 2004-2005. The mean age at baseline was 37.2 years, 55% were female, and the mean time lapsed between the baseline and follow-up questionnaires was 5.2 years. PM2.5 exposure was assessed from gravimetric data and routine nephelometry at monitoring stations located centrally with respect to the residence of most participants. Daily exposures to PM2.5 were averaged over the previous 12 months and mean daily exposure was 6.8 microg/m3. Logistic regression models were used to examine associations between PM2.5 exposure and adverse respiratory symptoms. Adjustment was made for age, gender, current smoking status, and medication use, but further adjustment for atopy did not alter the results. There was insufficient variability in PM2.5 exposure among participants over the study period to provide convincing evidence for or against associations between PM2.5 and adverse respiratory symptoms.

Bronchial hyperresponsiveness in women cooks and cleaners

The aim of this cross-sectional study was to assess the prevalence and characteristics of bronchial hyperresponsiveness (BHR) in 43 women cleaners (aged 26 to 57) and 37 women cooks (aged 29 to 55) and compare them with 45 controls (women office workers aged 27 to 58). The evaluation of all subjects included a questionnaire, skin prick tests to common aeroallergens, spirometry, and histamine challenge (PC20 < or = 8 mg mL(-1)). We found higher BHR prevalence in cleaners and cooks than in office workers (30.2 % and 29.7 %, vs. 17.7 %, respectively), but statistical significance was not reached. The prevalence of mild and moderate to severe BHR was similar in all groups. Borderline BHR prevalence was significantly higher in cleaners than in controls (16.2 % vs. 6.6 %, P=0.032) whereas the difference was on the verge of significance in cooks (13.5 % vs. 6.6 %, P=0.081). Moderate to severe BHR was strongly associated with positive family history of asthma and atopy in all groups. Mild BHR was significantly associated with daily smoking in cleaners (P=0.031) and cooks (P=0.021), as well as with the duration of exposure in cleaners (P=0.038). Borderline BHR was closely related to daily smoking and duration of exposure in both cleaners and cooks. Our findings indicate an important role of workplace exposure in borderline BHR development, as well as the significant effect of smoking on mild BHR development in women cleaners and cooks.

Lifestyle, occupational, and reproductive factors in relation to pancreatic cancer risk

OBJECTIVES

This study examined the epidemiology of pancreatic cancer in Egypt.

METHODS

We obtained detailed information on smoking, occupational, medical, and reproductive histories from 194 pancreatic cancer cases and 194 controls.

RESULTS

Compared with not smoking, smoking cigarettes alone or in conjunction with other smoking methods (eg, water pipe, cigar) was associated with an increased risk (odds ratio [OR], 4.5 and 7.8; 95% confidence interval [95% CI], 1.9-10.7 and 3.0-20.6, respectively). Passive smoking was also a significant risk factor (OR, 6.0; 95% CI, 2.4-14.8). The risk of pancreatic cancer was elevated among subjects exposed to pesticides (OR, 2.6; 95% CI, 0.97-7.2). A prior diagnosis of diabetes mellitus for a period of 10 years was associated with higher risk (OR, 5.4; 95% CI, 1.5-19.9). For women, having 7 or more live births and lactating for 144 months or longer were associated with a reduced risk (OR, 0.5 and 0.2; 95% CI, 0.2-1.3 and 0.1-0.9, respectively). No association was found between family history, allergy, or obesity and pancreatic cancer in Egypt.

CONCLUSIONS

Multiple tobacco consumption methods, passive smoking, pesticide exposures, and diabetes are associated with an increased risk for pancreatic cancer. Prolonged lactation and increased parity are associated with a reduced risk for pancreatic cancer.

Immunoglobulin E-Mediated Allergies in Lung-Transplanted Adults

BACKGROUND

Immunoglobulin E (IgE)-mediated allergy has repeatedly been reported after solid organ transplantation, apparently affecting approximately 10% of pediatric organ transplant recipients. Interestingly, type 1 allergy has not been described in transplanted adults, suggesting a particular propensity in childhood.

METHODS

The present cross-sectional study assessed the prevalence of type 1 allergy in 42 adult lung transplant recipients aged 25 to 50 years. Instruments included standardized interviews, skin prick tests, and serum IgE measurements.

RESULTS

Ten of 42 patients (23.8%) displayed elevated specific IgE levels or positive skin prick test results against one or more allergens. Five individuals (11.9%) additionally reported corresponding clinical symptoms of type 1 allergy. No statistically significant association of sensitization or allergy prevalence with patient age, kind of immunosuppressive therapy, and time since transplantation was found.

CONCLUSIONS

The phenomenon of transplantation-associated allergy is not age-restricted and thus should be assessed more thoroughly in all age groups.

Factors related to the level of severity of asthma in primary care

BACKGROUND

The severity of asthma varies in patients in primary care. The aim of this study was to identify factors related to asthma severity in a primary care setting.

METHODS

In this cross-sectional asthma study a random sample of 1477 patients, aged 15-45 years, from 42 primary health care centres received two questionnaires: one disease oriented and one quality of life oriented, MiniAQLQ. A classification of the asthma severity similar to the GINA guidelines was made with the information obtained from the questionnaire. The classification was based on current treatment, use of rescue medication, night symptoms, emergency consultations and use of oral steroids for treatment of exacerbations.

RESULTS

Thirty-five per cent of the women and 24% of the men were classified as having severe asthma. Women used more inhaled corticosteroids, more often took long acting beta-2 agonists or a leukotrien antagonist in addition to corticosteroids, experienced more frequent night awakenings and were more often smokers than men. In a multivariable analysis, female sex increased the odds of having severe asthma by 60% as compared with male sex, age by 3% per year, not having the asthma prescription filled owing to cost by 59%, daily smoking by 66% and pollen allergy by 85%.

CONCLUSIONS

Female sex, age, pollen and pet allergy, not having the asthma prescription filled owing to cost, and daily smoking were all independently associated with asthma severity.

Number of allergens to be tested to assess allergenic sensitization in epidemiologic studies: results of the European Community Respiratory Health Survey I

BACKGROUND

Many clinical and epidemiological studies have measured the prevalence of IgE sensitization using skin tests and/or serum-specific IgE. Most of them have been done in only one country using a battery of selected allergens relevant to that country. In multi-centre studies, the number of tested allergens is often limited by the cost. It is therefore difficult to compare prevalence of sensitized subjects between studies.

OBJECTIVE

To define the number and the type of allergen that should be tested in order to characterize a person as sensitized.

METHOD

Subjects were selected from the European Community Respiratory Health Survey I. All subjects underwent skin prick tests to nine of the most common allergens. In addition, two local allergens were tested in some centres.

RESULT

Using nine allergens, 35.6% of the 11 355 subjects were sensitized. The prevalence of sensitization increased with the number of tested allergens. Seven allergens enabled the identification of almost all sensitized subjects, adding another one inducing, in most countries, an increase of prevalence under 0.5%. Adding one local allergen to the battery of tests increased the overall estimated prevalence by only 1%. This increase was not seen in Ireland and was less marked in the United Kingdom (0.3%) but was greater in France (2.6%), Australia (2.5%) and Belgium (1.9%).

CONCLUSION

Seven selected allergens (Dermatophagoides pteronyssinus, cat, grass, birch, olive pollen, Alternaria and Cladosporium) allow the identification of almost all sensitized subjects in epidemiologic studies. Inclusion of local allergen should be considered in a standard panel for international studies.

Airway nitric oxide in patients with cystic fibrosis is associated with pancreatic function, Pseudomonas infection, and polyunsaturated fatty acids

BACKGROUND

Airway nitric oxide (NO) is low or normal in cystic fibrosis (CF) patients. This may affect bacterial status since NO has antimicrobial properties. Arachidonic acid (AA), which is increased in the serum and airways of CF patients, has been shown to reduce NO levels. The aim of this study was to investigate whether airway NO level correlates with genotype and pancreatic function, and whether low airway NO level is associated with bacterial infection and increased serum AA level in CF patients.

METHOD

Nasal NO (nNO) and exhaled NO (eNO) were measured according to the European Respiratory Society/American Thoracic Society standard in 59 CF patients aged 7 to 55 years, 80% of whom were pancreatic insufficient (PI) and 51% were chronically infected with Pseudomonas aeruginosa.

RESULTS

PI CF patients had significantly lower nNO levels than pancreatic-sufficient (PS) patients. Airway NO level did not correlate with lung function or inflammatory parameters. PI patients chronically infected with P aeruginosa had significantly lower nNO levels than noninfected PI patients. nNO level correlated inversely with the AA/docosahexaenoic acid ratio, and eNO with the essential fatty acid (FA) deficiency index, which is the ratio between mead acid and AA.

CONCLUSIONS

CF patients with PI, which is associated with more severe genotypes, had lower airway NO levels than patients with PS. Low NO level was correlated to chronic P aeruginosa infection, and an association was found between airway NO level and the abnormal serum phospholipid FA pattern.

Exhaled bronchial cysteinyl leukotrienes in allergic patients

PURPOSE OF REVIEW

To review the current knowledge of noninvasive monitoring of allergic airway inflammation by analysis of leukotrienes in the exhaled breath condensate.

RECENT FINDINGS

Treatment of respiratory allergies involves chronic treatment based on clinical symptoms and pulmonary function tests. Evaluation of local inflammation would be desirable but is currently not feasible because of the difficulty in sampling the airways. Recently, exhaled breath condensate collection and analysis has polarized much interest in the respiratory field. Although some methodological issues are still under scrutiny, airways inflammatory markers can be assayed with this technique. In particular, exhaled breath condensate leukotrienes have been thoroughly investigated in the setting of bronchial asthma and allergic rhinitis in adults and children. Exhaled leukotrienes are increased in patients with asthma and rhinitis during the pollen season, correlate with exacerbations and asthma severity, and are reduced by specific anti-inflammatory treatment and allergen avoidance.

SUMMARY

Some issues still prevent the use of exhaled breath condensate in clinical practice but in the research setting it has been proved to be useful for noninvasive monitoring of allergic inflammation in the lung. In particular, exhaled leukotrienes may represent valuable biomarkers for diagnostic and therapeutic purposes in allergic patients.

Association between personal exposure to volatile organic compounds and asthma among US adult population

OBJECTIVES

There is growing concern about adverse respiratory health effects from exposure to indoor air pollution. The purpose of this study was to analyze association between exposure to volatile organic compounds (VOC) and asthma in adults.

METHODS

This study utilized passive personal exposure data on ten VOC collected as part of the National Health and Nutrition Examination Survey (NHANES) 1999-2000. A total of 550 subjects who were of non-Hispanic whites, Mexican-Americans, or non-Hispanic Blacks race/ethnicity were included in this analysis. The primary outcome variable was physician-diagnosed asthma and the secondary outcome variable was presence of wheezing in the previous 12 months among those without physician-diagnosed asthma. Exploratory factor analysis was used to generate factor scores to group VOCs, which were included as indicator variables in the analyses. Associations between exposure to VOCs, physician-diagnosed asthma, and wheezing in the previous 12 months were evaluated using multiple logistic regression analyses. Odds ratios are for 1-U increase in level of exposure.

RESULTS

Seven of the ten VOC variables loaded on two factors, "aromatic compounds" and "chlorinated hydrocarbons." The geometric mean concentration of VOCs varied from as low as 0.03 microg/m3 for trichloroethene to as high as 14.33 microg/m3 for toluene. Mexican-Americans had the highest personal exposures to benzene (geometric mean=2.38 microg/m3) as compared to non-Hispanic whites (geometric mean=1.15 microg/m3) and non-Hispanic Blacks (geometric mean=1.07 microg/m3). The odds of physician-diagnosed asthma were significantly higher among those exposed to aromatic compounds (Adjusted OR=1.63, 95% CI: 1.17-2.27). Among those subjects never diagnosed by a physician to have asthma, a significantly increased odds of one to two wheezing attacks were observed for aromatic compounds (Adjusted OR=1.68, 95% CI: 1.08-2.61) and chlorinated hydrocarbons (Adjusted OR=1.50, 95% CI: 1.01-2.23) as compared to no wheezing. No association with three wheezing attacks or more was observed in the study.

CONCLUSION

In this cross-sectional study of a representative sample of the US population, environmental exposures to VOCs, especially aromatic compounds, were associated with adverse respiratory effects.

[Prevalence of asthma in college student population]

INTRODUCTION

Bronchial asthma is common chronic disease among young people and prevalence of this condition has been constantly growing over past two decades throughout the world.

OBJECTIVE

To establish the prevalence of asthma in student population of Belgrade University and to determine the frequency distribution in regard to their permanent residence.

METHOD

Data obtained from annual physical examinations of 118 342 students (age 19-23 years) treated at the Student's Health Care Institute between 1996-2001 were analyzed. Affirmative answer to the question: "Are you currently treated", or "Have you ever been treated for asthma" indicated diagnosis of asthma. Data on student's age, gender, permanent residence, and smoking habits were collected.

RESULTS

The prevalence of asthma was 3680/100.000 and mildly growing trend was noted over the last several years (from 2.96% to 4.05%) (F = 42.427; df=4; p < 0.01). Asthma was more prevalent in females (57%) than among males (43%) (chi2 = 91.189; df=1; p < 0.01). Several regions with increased asthma incidence were identified and the causes of such findings still need to be clarified. Cigarette smoking was common in students (chi2 = 236.781; df=1; p < 0.01), but also among asthmatics [one out of three students was a smoker (chi2= 8.141; df=1; p < 0.01)].

CONCLUSION

The prevalence of asthma in student population is 3.68% with mildly growing trend over the last years. The disease is more prevalent in females. Cigarette smoking is common in students as well as among asthmatics. To our knowledge, this is the first study on prevalence of asthma in young adult population in our country.

Geographical variation in the prevalence of positive skin tests to environmental aeroallergens in the European Community Respiratory Health Survey I

BACKGROUND

Many studies have reported the prevalence of sensitization using skin prick tests. However, comparisons between studies and between regions are difficult because the number and the type of allergens tested vary widely. Using the European Community Health Respiratory Survey I data, the geographical variation of sensitization to environmental allergen as measured by skin tests was established.

METHODS

Adults aged 20-44 years, living in 35 centres in 15 developed countries, underwent skin tests for allergy to nine common aeroallergens: Dermatophagoides pteronyssinus, timothy grass, cat, Cladosporium herbarium, Alternaria alternata, birch, Olea europea, common ragweed and Parietaria judaica. The age-sex standardized prevalence of sensitization was determined and centres with high (95% confidence interval above and excluding study median) and low prevalence (95% confidence interval below and excluding study median) of sensitization to each allergen and to any of the nine allergens were identified.

RESULTS

There was substantial geographical variation in the prevalence of sensitization to each of the nine allergens tested and in the prevalence of sensitization to any allergen (lowest 17.1%, median 36.8% and highest 54.8%). Sensitization to D. pteronyssinus, grass pollen and cat were usually the most prevalent (median between centre 21.7%, 16.9% and 8.8%, respectively). Timothy grass sensitization was higher than that for any other pollen species.

CONCLUSIONS

As expected, geographical variations of sensitization to environmental allergen were observed across centres. These findings were compatible for those observed with serum-specific IgE. Skin tests can be used to assess the geographical distribution of allergens in a multicentric epidemiological survey.

Occupational risk factors for asthma among nurses and related healthcare professionals in an international study

OBJECTIVE

The authors examined the relations between self-reported work tasks, use of cleaning products and latex glove use with new-onset asthma among nurses and other healthcare workers in the European Community Respiratory Health Survey (ECRHS II).

METHODS

In a random population sample of adults from 22 European sites, 332 participants reported working in nursing and other related healthcare jobs during the nine-year ECRHS II follow-up period and responded to a supplemental questionnaire about their principal work settings, occupational tasks, products used at work and respiratory symptoms. Poisson regression models with robust error variances were used to compare the risk of new-onset asthma among healthcare workers with each exposure to that of respondents who reported professional or administrative occupations during the entire follow-up period (n = 2481).

RESULTS

Twenty (6%) healthcare workers and 131 (5%) members of the referent population reported new-onset asthma. Compared to the referent group, the authors observed increased risks among hospital technicians (RR 4.63; 95% CI 1.87 to 11.5) and among those using ammonia and/or bleach at work (RR 2.16; 95% CI 1.03 to 4.53).

CONCLUSIONS

In the ECRHS II cohort, hospital technicians and other healthcare workers experience increased risks of new-onset current asthma, possibly due to specific products used at work.

Global alliance against chronic respiratory diseases

Hundreds of millions of people of all ages suffer from chronic respiratory diseases which include asthma and respiratory allergies, chronic obstructive pulmonary disease, occupational lung diseases and pulmonary hypertension. More than 500 million patients live in developing countries or in deprived populations. Chronic respiratory diseases are increasing in prevalence. Although the cost of in action is clear and unacceptable, chronic respiratory diseases and their risk factors receive in sufficient attention from the health care community, government officials, media, patients and families. The Fifty-Third World Health Assembly recognized the enormous human suffering caused by chronic diseases and requested the World Health Organization (WHO) Director General to give priority to the prevention and control of chronic diseases, with special emphasis on developing countries. This led to the formation of the WHO Global Alliance against Chronic Respiratory Diseases (GARD). GARD is a voluntary alliance of organizations, institutions and agencies working towards a common vision to improve global lung health according to local needs. GARD is developed in a stepwise approach using the following three planning steps: estimate population need and advocate action; formulate and adopt policy; and identify policy implementation steps.

Long-acting beta2-agonists for chronic asthma in adults and children where background therapy contains varied or no inhaled corticosteroid

BACKGROUND

Asthma is a common respiratory disease among both adults and children and short acting inhaled beta-2 agonists are used widely for 'reliever' bronchodilator therapy. Long acting beta-2 agonists (LABA) were introduced as prospective 'symptom controllers' in addition to inhaled corticosteroid 'preventer' therapy (ICS). In this updated review we have included studies in which patients were either not on ICS as a group, or in which some patients, but not all, were on ICS to complement previous systematic reviews of studies where LABA was given in patients uniformly receiving ICS. We have focussed particularly on serious adverse events, given previous concerns about potential risks, especially of death, from regular beta-2 agonist use.

OBJECTIVES

This review aimed to determine the benefit or detriment on the primary outcome of asthma control with the regular use of LABA compared with placebo, in mixed populations in which only some were taking ICS and in populations not using ICS therapy.

SEARCH STRATEGY

We carried out searches using the Cochrane Airways Group trial register, most recently in October 2005. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least four weeks duration, comparing a LABA given twice daily with a placebo, in chronic asthma. Selection criteria to this updated review have been altered to accommodate recently published Cochrane reviews on combination and addition of LABA to ICS therapy. Studies in which all individuals were uniformly taking ICS were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.

MAIN RESULTS

Sixty-seven studies (representing 68 experimental comparisons) randomising 42,333 participants met the inclusion criteria. Salmeterol was used as long-acting agent in 50 studies and formoterol fumarate in 17. The treatment period was four to nine weeks in 29 studies, and 12 to 52 weeks in 38 studies. Twenty-four studies did not permit the use of ICS, and forty permitted either inhaled corticosteroid or cromones (in three studies this was unclear). In these studies between 22% and 92% were taking ICS, with a median of 62%. There were significant advantages to LABA treatment compared to placebo for a variety of measurements of airway calibre including morning peak expiratory flow (PEF), evening PEF and FEV1. They were associated with significantly fewer symptoms, less use of rescue medication and higher quality of life scores. This was true whether patients were taking LABA in combination with ICS or not. Findings from SMART (a recently published surveillance study) indicated significant increases in asthma related deaths, respiratory related deaths and combined asthma related deaths and life threatening experiences. The absolute increase in asthma-related mortality was consistent with an increase of around one per 1250 patients treated with LABA for six months, but the confidence intervals are wide (from 700 to 10,000). Post-hoc exploratory subgroups suggested that African-Americans and those not on inhaled corticosteroids were at particular risk for the primary end-point of death or life-threatening asthma event. There was also a suggestion of an increase in exacerbation rate in children. Pharmacologically predicted side effects such as headache, throat irritation, tremor and nervousness were more frequent with LABA treatment.

AUTHORS' CONCLUSIONS

LABA are effective in the control of chronic asthma in the "real-life" subject groups included. However there are potential safety issues which call into question the safety of LABA, particularly in those asthmatics who are not taking ICS, and it is not clear why African-Americans were found to have significant differences in comparison to Caucasians for combined respiratory-related death and life threatening experiences, but not for asthma-related death.

Gender and age differences in the relative burden of rhinitis and asthma on health-related quality of life--a Swedish population study

The aim of this study was to investigate the relative burden of rhinitis and asthma on health-related quality of life (HRQL) as a function of gender and age in the general population. A cross-sectional, general population survey was conducted, comprising 5918 men and women aged 16-64 years. The SF-36 Health Survey was administered by mail, along with questions regarding nasal complaints after 15 years of age and physician-diagnosed asthma. Overall, rhinitis and asthma were each associated with impaired HRQL compared with non-cases and the burden of these illnesses in combination was incremental. In the age group 16-49 years, men and women with rhinitis alone had significantly worse health profiles on most scales than non-cases, while asthmatics, with or without rhinitis, showed further decrements on only a few scales. In the age group 50-64 years, men with rhinitis did not differ from non-cases and no differences were found between asthmatics and rhinitis victims on any scale. In contrast, women aged 50-64 years with rhinitis had significantly worse scores than non-cases on bodily pain and general well-being scales (GH, VT), and asthmatics scored much lower on all scales than those with rhinitis alone. The negative association of rhinitis and asthma with HRQL differs by age and sex in the general population. Women aged 50-64 years with one or both ailments are particularly affected. Such gender and age differences should be taken into consideration in the care and treatment of patients with rhinitis and asthma.

Current asthma and respiratory symptoms among pupils in Shanghai, China: influence of building ventilation, nitrogen dioxide, ozone, and formaldehyde in classrooms

We investigated 10 naturally ventilated schools in Shanghai, in winter. Pupils (13-14 years) in 30 classes received a questionnaire, 1414 participated (99%). Classroom temperatures were 13-21 degrees C (mean 17 degrees C), relative air humidity was 36-82% (mean 56%). The air exchange rate was 2.9-29.4 ac/h (mean 9.1), because of window opening. Mean CO2 exceeded 1000 ppm in 45% of the classrooms. NO2 levels were 33-85 microg/m3 indoors, and 45-80 microg/m3 outdoors. Ozone were 1-9 microg/m3 indoors and 17-28 microg/m3 outdoors. In total, 8.9% had doctors' diagnosed asthma, 3.1% wheeze, 23.0% daytime breathlessness, 2.4% current asthma, and 2.3% asthma medication. Multiple logistic regression was applied. Observed indoor molds was associated with asthma attacks [odds ratio (OR) = 2.40: P < 0.05]. Indoor temperature was associated with daytime breathlessness (OR = 1.26 for 1 C; P < 0.001), and indoor CO2 with current asthma (OR = 1.18 for 100 ppm; P < 0.01) and asthma medication (OR = 1.15 for 100 ppm; P < 0.05). Indoor NO2 was associated with current asthma (OR = 1.51 for 10 microg/m3; P < 0.01) and asthma medication (OR = 1.45 for 10 microg/m3; P < 0.01). Outdoor NO2 was associated with current asthma (OR = 1.44 for 10 microg/m3; P < 0.05). Indoor and outdoor ozone was negatively associated with daytime breathlessness. In conclusion, asthma symptoms among pupils in Shanghai can be influenced by lack of ventilation and outdoor air pollution from traffic. Practical Implications Most urban schools in Asia are naturally ventilated buildings, often situated in areas with heavy ambient air pollution from industry or traffic. The classes are large, and window opening is the only way to remove indoor pollutants, but this results in increased exposure to outdoor air pollution. There is a clear need to improve the indoor environment in these schools. Building dampness and indoor mold growth should be avoided, and the concept of mechanical ventilation should be introduced. City planning aiming to situate new schools away from roads with heavy traffic should be considered.

Asthma out of control? A structured review of recent patient surveys

BACKGROUND

An understanding of the needs and behaviors of asthma patients is important in developing an asthma-related healthcare policy. The primary goal of the present review was to assess patient perspectives on key issues in asthma and its management, as captured in patient surveys.

METHODS

Local, national, and multinational asthma surveys were reviewed to assess patient perspectives, and where possible healthcare provider (HCP) perspectives, on key issues, including diagnosis, treatment, control, quality of life, and other patient-centered outcomes. Twenty-four surveys, conducted or published between 1997 and 2003 in Europe and North America, were included in this review. Substantial differences among studies prevented a formal meta-analysis; instead, data were pooled to allow for general comparisons and qualitative analysis.

RESULTS

The results indicate that patients' knowledge of the underlying causes of asthma and treatment options remains inadequate. Moreover, patients often tolerate poor symptom control, possess meager knowledge of correct drug usage, and display insufficient adherence to therapy. Many patients have a low expectation of receiving an appropriate therapy or of having a positive encounter with the HCP. Among HCPs, there is evidence of inadequate understanding of disease etiology and poor or unstructured communication with patients, resulting often in inaccurate assessment of disease severity. Moreover, patients often underreport their symptoms and severity, which in turn could lead to misclassification and undertreatment.

CONCLUSION

Improving patient education about the importance of achieving optimal asthma control, along with improved communication between patients and HCPs, emphasizing treatment options and optimal treatment of inflammation, may lead to better outcomes and improved asthma management in daily practice.

Asthma control in Spain. Do season and treatment pattern matter? The ESCASE study

The aim of this study was to assess the degree of asthma control according to GINA criteria during two different seasons in Spain. An multicenter, longitudinal, epidemiological study with the participation of a sample of physicians in Spain was conducted. Consecutive asthma patients, 18 years of age and older, seeking primary and specialist care were included in the study. Patients were seen during the winter and spring 2004 and were asked about asthma control according to GINA control criteria (daytime and nighttime symptoms, asthma exacerbations, limitations of physical activity, and visits to the emergency department) during the 4 weeks prior to the visit. Control was defined according to daytime and nighttime symptoms. A total of 614 patients participated in the study. The proportion of patients reporting daytime symptoms "every day" or "most days" during the winter versus spring was 40.1% vs. 23% (P<0.01); 26.9% vs. 14.1% presented symptoms at night (P<0.01); 11.5% vs. 8.3% had severe exacerbations; 33.5% vs. 35.7% presented symptoms accompanying exercise, and 9.4% vs. 4.3% (P<0.01) had required emergency visits. The number of patients with inadequate control was slightly higher in winter than in spring (74.4% vs. 71%) (P<0.01). The most commonly prescribed treatment was ICS plus LABAs for both periods. Asthma is poorly controlled in Spain and strategies are needed to improve management of this illness.

History of allergies and risk of glioma in adults

Epidemiological studies have consistently reported an inverse association between a history of allergic disease and risk of glioma. The reason for this association is unclear, and there is a lack of studies with the detail and size to explore the association in depth. We conducted a UK population-based case-control study with 965 glioma cases and 1,716 controls to investigate glioma risk in relation to allergic disease. Risk was reduced in subjects reporting a history of asthma (odds ratio (OR) = 0.71, 95% confidence interval (CI): 0.54-0.92), hay fever (OR = 0.73, 95% CI: 0.59-0.90), eczema (OR = 0.74, 95% CI: 0.56-0.97) and other allergies (OR = 0.65, 95% CI: 0.47-0.90). Risk was reduced for all the main histological groups. There was no significant trend of risk with age, at the onset of each condition, or the number of conditions reported. Risk reductions were strongest for asthma or hay fever with recent onset. Risk in asthmatic subjects was not related to frequency of use of antiasthmatic drugs, but was significantly reduced for use of antiallergenic medication among subjects with hay fever. The study showed an inverse association of glioma risk with allergic disease. Possible reasons for the association, as well as potential immunological aetiology, include confounding, bias and reverse causality.

Inverse association between periodontitis and respiratory allergies

BACKGROUND

Periodontitis is an infection with systemic effects and a high prevalence among adults. In the aetiology of allergic diseases the hygiene hypothesis claims that infections in early infancy may protect against allergic diseases.

OBJECTIVE

The aim of the present analyses was to investigate the independent relation between periodontitis and respiratory allergies such as hayfever, house dust mite (HDM) allergy and asthma.

METHODS

From the Study of Health in Pomerania (SHIP) a total number of 2837 subjects aged 20 to 59 years were included in the analysis. In our study population 326, 111 and 114 subjects were classified as suffering from hayfever, HDM allergy or asthma, respectively. The attachment loss (AL) were measured. Periodontitis was defined according to the percentage of surfaces which exceeded 3 mm AL [healthy: 0-7.7%, mild: 7.8-28.6%, moderate: 28.7-63.9%, severe: >63.9%]. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression.

RESULTS

After adjustment for confounding factors these analyses revealed inverse associations between periodontitis and hayfever as well as periodontitis and HDM allergy. For increasing AL, a trend of decreasing risk could be observed for hayfever (healthy: reference; mild AL: OR 0.87 [95%-CI 0.6-1.2]; moderate AL: OR 0.80 [95% CI 0.6-1.2]; server AL: OR 0.53 [95% CI 0.3-0.9]; P(trend)=0.01) and for HDM allergy (healthy: reference; mild AL: OR 0.80 [95% CI 0.5-1.3]; moderate AL: OR 0.64 [95% CI 0.3-1.2]; server AL: OR 0.39 [95% CI 0.2-0.9]; P(trend)=0.02). Furthermore, for asthma were observed a slightly inverse association in the full-adjusted model (healthy: reference; mild AL: OR 1.10 [95% CI 0.6-2.0]; moderate AL: OR 0.96 [95% CI 0.5-1.8]; server AL: OR 0.48 [95% CI 0.2-1.0]; P(trend)=0.11).

CONCLUSION

There is an inverse association between periodontitis and respiratory allergies. Our results might support the hygiene hypothesis.

Detection of allergens adsorbed to ambient air particles collected in four European cities

Air pollution has been implicated as one of the factors responsible for the increased incidence of allergic diseases observed in recent years. High concentrations of air pollutants may promote airway sensitization by acting as adjuvants. Ambient particles as carriers of adsorbed allergens are, therefore, of special interest since they may act as mediators of inflammatory as well as allergic responses. Ambient air particles from four cities in Europe were collected, in three different seasons, to examine the variation of allergens and their possible binding to the pollution particles. The particle fraction, PM10, was collected on polycarbonate filters using a low-volume sampling regime. The presence of pollen allergens, latex and beta-glucans was investigated using an immunogold labelling method directly on the collection filters. Scanning electron microscopy revealed mainly the classical carbon particles and aggregates determined to originate from vehicle exhaust. The immunogold labelling visualised in the backscatter electron imaging mode, showed that allergens from pollens, latex and also beta-glucans were bound to and, hence, transported by the combustion particles in ambient air. Thus, combustion particles in ambient air are carriers of allergens and act as depots of allergens inhaled into the airways.

House dust mite allergen reduction and allergy at 4 yr: follow up of the PIAMA-study

Exposure to high allergen levels in early life is a risk factor for the development of allergy. We previously reported limited effects of mite allergen impermeable mattress covers in the prevention and incidence of asthma and mite allergy (PIAMA) cohort at the age of 1 and 2 yr. We now present the results of follow-up at 4 yr objectives. To examine the effects of early reduction of house dust mite (HDM) allergen exposure by means of mattress covers on the incidence of allergy and asthma symptoms in the PIAMA birth cohort at the age of 4 yr. High-risk children (allergic mother) were prenatally recruited and randomly allocated to three groups; receiving mite allergen impermeable mattress covers (n = 416), placebo covers (n = 394) or no intervention (n = 472). At 4 yr of age, atopy was assessed by questionnaire; specific Immunoglobulin E (IgE) to inhalant and food allergens was measured in serum. Dust samples collected from the children's mattresses were analysed for mite allergens. Dermatophagoides farinae1 allergen (Der f 1) levels in dust were reduced in the active group. However, Dermatophagoides pteronissinus 1 (Der p 1) levels, sensitization and atopic symptoms were similar in all groups. We found no effect of mite allergen impermeable mattress covers on sensitization and atopy at 4 yr. Moreover, the allergen reducing effects of the covers had disappeared for one of the two mite allergens that were measured.

Asthma, eczema, and reports on pollen and cat allergy among pupils in Shanxi province, China

OBJECTIVES

To study self-reported asthma, eczema, and pollen and furry pet allergy among pupils (9-20 years) in Shanxi province, China, in relation to dietary and environmental factors.

METHODS

A standardised questionnaire was distributed to pupils in two primary and two secondary schools, one in Taiyuan city (3.0 milj. inhabitants), the others in Qingxu county, a rural area 30 km outside Taiyuan. Totally, 2,116 pupils (90%) participated.

RESULTS

Fifty percent were girls, 61% had been growing up on the countryside, 18% lived in Taiyuan now, 1.7% had ever had asthma, 0.8% had doctor's diagnosed asthma, 1.4% pollen allergy, 1.7% cat allergy, and 0% had dog allergy. Multiple logistic regression was applied, controlling for age, gender, diet, indoor exposures, rural childhood, and current urban residency. Girls had less eczema (OR = 0.51; 95%CI 0.28-0.92). Pupils in the city had more eczema (OR = 5.05; 95% CI 1.11-23.3). Those with a rural childhood had less asthma (OR = 0.17; 95% CI 0.05-0.60), eczema (OR = 0.15; 95% CI 0.13-0.66) and pollen/cat allergy (OR = 0.50; 95%CI 0.25-0.99). None of the indoor variables was related to asthma or allergy. Children with frequent fruit consumption had less asthma (OR = 0.40; 95% CI 0.19-0.82) and pollen/cat allergy (OR = 0.49; 95% CI 0.29-0.84). Those with frequent fish consumption had less asthma (OR = 0.32; 95% CI 0.11-0.97). Those with frequent hamburgers consumption had more asthma (OR = 2.05; 95% CI 1.09-3.87) and eczema (OR = 1.85; 95% CI 1.12-3.04).

CONCLUSION

Asthma, eczema, and pollen or pet allergy was uncommon, compared with western countries and other areas in China. Pupils with a rural childhood had less asthma and allergy, which is consistent with the "hygiene hypothesis". Fruit and fish consumption may reduce, and fast food consumption may increase the risk for asthma. Finally, the higher prevalence of asthma and eczema among younger children, born in the 1990s, indicates a cohort effect similar to that observed in western countries.

Working towards healthy air in dwellings in Europe

Poor indoor air quality has been implicated in the increase in allergic and respiratory diseases seen in industrialized countries in recent decades. Although air pollution in the workplace is well studied, much less is known about the consequences of poor air quality in homes. In an attempt to halt or slow down the increase in allergic and respiratory diseases, the European Federation of Allergy and Airways Diseases Patients Associations (EFA) carried out the EU-funded project entitled 'Towards Healthy Air in Dwellings in Europe' (THADE). The aims were to: compile an overview of evidence-based data about exposure to indoor air pollution and its health effects, particularly in relation to allergies, asthma and other respiratory diseases such as chronic obstructive pulmonary disease; review cost-effective measures and technology to improve indoor air quality; review legislation and guidelines on indoor air pollution; produce maps of pollutants in dwellings; and recommend an integrated strategy that defines appropriate indoor air quality policies for implementation in Europe. This paper summarizes the information about air quality in dwellings and indoor environment-related diseases collected by expert consultants within the framework of THADE and terminates with recommendations for actions aimed at improving air quality in homes. The results of this project confirmed that air pollution in dwellings is a relevant health problem. It is a complex problem that must be addressed at European and international levels, and it involves the medical profession, scientific societies, patients' organizations, lawmakers, architects and the building industry. The complete THADE report is available at http://www.efanet.org/activities/documents/THADEReport.pdf.

The proportion of self-reported asthma associated with work in three States: California, Massachusetts, and Michigan, 2001

OBJECTIVES

To assess the proportion of adult asthma at the state level that may be related to work.

DESIGN

Work-related asthma questions were added to the 2001 Behavioral Risk Factor Surveillance System (BRFSS) questionnaire in California, Massachusetts, and Michigan.

RESULTS

Findings indicate 7.4-9.7% of those with current asthma reported that their asthma may be work related. These results estimate that approximately 137,000 adults in California, 39,000 in Massachusetts, and 63,000 in Michigan have asthma that may be work related.

CONCLUSIONS

These findings are unique in providing population-based estimates at the state level that illustrate that a substantial portion of adult asthma morbidity is due to exposures in the work environment.

Is outdoor air pollution associated with physician visits for allergic rhinitis among the elderly in Toronto, Canada?

BACKGROUND

While a number of studies suggest that air pollution is associated with allergic rhinitis in children, findings among adults have been equivocal. The aim of this study was to examine the relationship between outdoor air pollution and physician visits for allergic rhinitis among individuals>or=65 years of age in Toronto, Canada.

METHODS

Physician visits were identified by using data from the Ontario provincial health insurance plan that is made available to all residents. Our analyses are based on 52,691 physician visits for allergic rhinitis among individuals>or=65 years of age in the Toronto metropolitan area between 1995 and 2000. Generalized linear models were used to regress daily counts of physician visits against daily measures of gaseous and particulate components of air pollution after controlling for seasonality, potential confounders (temperature, relative humidity, aeroallergens), overdispersion and serial correlation.

RESULTS

A large number of comparisons were undertaken, with most showing no statistically significant associations between daily levels of air pollution and the number of physician visits for rhinitis. In contrast, an interquartile increase in the 10-day average of ragweed particles increased the mean number of daily rhinitis consultations by 6.4% (95% CI=0.7-12.4%).

CONCLUSIONS

Our findings suggest that outdoor air pollution is a poor predictor of physician visits for allergic rhinitis among the elderly.

Smoking, respiratory symptoms and likely asthma in young people: evidence from postal questionnaire surveys in the Wythenshawe Community Asthma Project (WYCAP)

BACKGROUND

Although it is recognised that smoking is a major risk factor for subjects with chronic obstructive pulmonary disease and is associated with respiratory symptoms, there is less agreement concerning the relationship between asthma and smoking. This study aims to examine the relationship between cigarette smoking and asthma prevalence.

METHOD

Data were used from two postal questionnaire surveys (1999 and 2001) in two general practice populations, using a respiratory questionnaire based on the ECRHQ and a generic quality of life questionnaire (EQ-5D). Only subjects less than 45 years old were included in the survey. An empirical definition of likely asthma was used based on respiratory questionnaire responses. Smoking was examined according to three categories, current smoker, ex smoker and never smoker.

RESULTS

Almost 3500 subjects were included in the analyses. Current smokers had a higher prevalence of likely asthma compared to never smokers, odds ratio (OR) 1.59 (95% confidence interval (CI) 1.24 to 2.04). and also compared to ex smokers OR 1.79 (CI 1.25 to 2.56), but there was no difference between ex smokers and never smokers (OR 1.00 (0.75-1.35)). Current smoking was also positively associated with all symptoms but not with a history of hayfever/eczema.

CONCLUSION

Although the positive association found between current smoking and obstructive airways disease is likely to be due to the effect of cigarettes on asthma, it could reflect an association with early COPD (GOLD stages 0 or 1). Smoking cessation has a beneficial effect on the prevalence of respiratory symptoms and is therefore of paramount importance among these young adults.

Uncontrolled asthma: a review of the prevalence, disease burden and options for treatment

An estimated 300 million people are affected by asthma worldwide and the burden is likely to rise substantially in the next few decades. Estimates of the prevalence of asthma range from 7% in France and Germany to 11% in the USA and 15-18% in the United Kingdom. Approximately 20% of these patients have severe asthma, of which 20% is inadequately controlled. Patients with inadequately controlled severe persistent asthma are at a particularly high risk of exacerbations, hospitalization and death, and often have severely impaired quality of life. Current management of asthma focuses on a stepwise approach tailored to disease severity. In addition to needing high-dose inhaled corticosteroids (ICS) and long-acting beta(2)-agonists (LABAs), patients with severe persistent asthma often require additional controller medications, such as anti-leukotrienes, oral LABAs, oral corticosteroids and/or anti-IgE therapy. There is currently little evidence on which to base treatment decisions in patients with inadequately controlled severe persistent asthma already treated with ICS and LABAs. The anti-IgE monoclonal antibody omalizumab is the most recent addition to the list of treatment options for these patients and has been shown to reduce exacerbations and emergency visits and improve lung function, symptom scores and quality of life in patients with difficult-to-treat asthma whose symptoms remain inadequately controlled despite receiving ICS and LABAs. Comparative trials are needed to determine the merits of different treatments and strategies for patients with inadequately controlled severe persistent asthma and to identify patients likely to benefit from new treatment options.

Common genetic variants of the FADS1 FADS2 gene cluster and their reconstructed haplotypes are associated with the fatty acid composition in phospholipids

Fatty acid composition in membranes plays an important role in cellular processes and has shown to be associated with the aetiology of several complex diseases in humans. We report strong associations between variants in the human delta-5 and delta-6 desaturase genes FADS1 FADS2 and fatty acid composition in serum phospholipids. Eighteen polymorphisms located in this gene cluster were genotyped in 727 adults from Erfurt, a German centre of the European Community Respiratory Health Survey. The cluster is located at chromosome 11q12-11q13.1, a region repeatedly found to be linked with atopy and other complex diseases. Polymorphisms and statistically reconstructed haplotypes of FADS1 and the upstream region of FADS2 showed strongest associations with the level of the direct precursor of inflammatory eicosanoids, the n-6 fatty acid arachidonic acid (C20:4n-6), also strong associations with levels of the n-6 fatty acids C18:2n-6, C18:3n-6, C20:2n-6, C20:3n-6, C22:4n-6 and of the n-3 fatty acids C18:3n-3, C20:5n-3 and C22:5n-3 (P-values < 1.0 x 10(-13)). Carriers of the rare alleles of several SNPs and their respective haplotypes had a lower prevalence of allergic rhinitis and atopic eczema. No association was found for total and specific IgE levels.

Comparison of oxidative properties, light absorbance, total and elemental mass concentration of ambient PM2.5 collected at 20 European sites

OBJECTIVE

It has been proposed that the redox activity of particles may represent a major determinant of their toxicity. We measured the in vitro ability of ambient fine particles [particulate matter with aerodynamic diameters<or=2.5 microm (PM2.5)] to form hydroxyl radicals (.OH) in an oxidant environment, as well as to deplete physiologic antioxidants (ascorbic acid, glutathione) in the naturally reducing environment of the respiratory tract lining fluid (RTLF). The objective was to examine how these toxicologically relevant measures were related to other PM characteristics, such as total and elemental mass concentration and light absorbance.

DESIGN

Gravimetric PM2.5 samples (n=716) collected over 1 year from 20 centers participating in the European Community Respiratory Health Survey were available. Light absorbance of these filters was measured with reflectometry. PM suspensions were recovered from filters by vortexing and sonication before dilution to a standard concentration. The oxidative activity of these particle suspensions was then assessed by measuring their ability to generate .OH in the presence of hydrogen peroxide, using electron spin resonance and 5,5-dimethyl-1-pyrroline-N-oxide as spin trap, or by establishing their capacity to deplete antioxidants from a synthetic model of the RTLF.

RESULTS AND CONCLUSION

PM oxidative activity varied significantly among European sampling sites. Correlations between oxidative activity and all other characteristics of PM were low, both within centers (temporal correlation) and across communities (annual mean). Thus, no single surrogate measure of PM redox activity could be identified. Because these novel measures are suggested to reflect crucial biologic mechanisms of PM, their use may be pertinent in epidemiologic studies. Therefore, it is important to define the appropriate methods to determine oxidative activity of PM.

Asthma, current wheezing, and tobacco use among adolescents and young adults in Costa Rica

OBJECTIVES

To examine the prevalence of asthma and the relation between tobacco use and asthma among university students in Costa Rica.

METHODS

Cross-sectional study of 1279 adolescents and young adults enrolled in careers in the health sciences in public and private universities in Costa Rica.

RESULTS

Of the 1279 study participants, 105 (8.2%) had current asthma, and 136 (10.6%) reported wheezing in the previous 12 months (current wheezing). Among individuals with either current wheezing or current asthma, none was using anti-inflammatory medications for asthma (e.g., inhaled corticosteroids). Approximately one third of the study participants reported any cigarette smoking. Young adults who had current wheezing were 5.8 times more likely to smoke at least 10 cigarettes per day than those who had no current wheezing [95% confidence interval (CI) for odds ratio (OR) = 3.3-10.2, p < 0.001]. Similar results were observed when an alternative definition of asthma (current asthma) was used in the analysis (OR for smoking at least 10 cigarettes per day = 4.4, 95% CI = 2.3-8.5, p < 0.001).

CONCLUSIONS

Adequate public health measures are needed to prevent tobacco use in Costa Rican adolescents and to promote smoking cessation among young adults. Young adults with asthma living in Latin American countries with high asthma prevalence, such as Costa Rica, should be better educated with regard to asthma and the risks of tobacco use.

Prevalence of Bronchial Hyperresponsiveness and Asthma in the Adult Population in Thailand

OBJECTIVES

We conducted a nationwide cross-sectional survey of respiratory health in adults aged 20 to 44 years during 2001 to 2002 to determine the prevalence of bronchial hyperresponsiveness (BHR) and asthma in the adult Thai population.

DESIGN

Subjects were selected by a multistage stratified random sampling. The stratification was done on geographic area, age group, and sex. Subjects were interviewed with questionnaires and underwent spirometric testing. Methacholine challenge tests were performed on all subjects without contraindication to determine BHR defined as the provocative concentration of methacholine producing a 20% fall in FEV(1) < or = 8 mg/mL. Definite asthma was defined as BHR present with any asthma symptom within the past 12 months or demonstrated reversible airflow obstruction. Current diagnosed asthma was defined as previous physician-diagnosed asthma and any asthma symptom within the past 12 months or currently receiving asthma medication.

RESULTS

The study population was from 20 provinces of five geographic regions of Thailand and included 1,882 women and 1,572 men. The prevalence of BHR was 3.31% (95% confidence interval [CI], 2.68 to 3.94). However, if subjects with positive reversibility test results were included, the prevalence increased to 3.98% (95% CI, 3.30 to 4.67). The prevalence of definite asthma was 2.91% (95% CI, 2.32 to 3.50), whereas the prevalence of current diagnosed asthma by the questionnaire interview was 2.15% (95% CI, 1.66 to 2.63). The kappa index of the agreement between both definitions of asthma was 0.40, indicating poor to fair agreement.

CONCLUSION

The prevalence of BHR and asthma in the adult Thai population is relatively low as compared with western countries.

Greater risk of incident asthma cases in adults with allergic rhinitis and effect of allergen immunotherapy: a retrospective cohort study

Asthma and rhinitis are often co-morbid conditions. As rhinitis often precedes asthma it is possible that effective treatment of allergic rhinitis may reduce asthma progression.

The aim of our study is to investigate history of allergic rhinitis as a risk factor for asthma and the potential effect of allergen immunotherapy in attenuating the incidence of asthma.

Hospital-referred non-asthmatic adults, aged 18–40 years between 1990 and 1991, were retrospectively followed up until January and April 2000. At the end of follow up, available subjects were clinically examined for asthma diagnosis and history of allergen specific immunotherapy, second-hand smoking and the presence of pets in the household. A total of 436 non-asthmatic adults (332 subjects with allergic rhinitis and 104 with no allergic rhinitis nor history of atopy) were available for final analyses.

The highest OR (odds ratio) associated with a diagnosis of asthma at the end of follow-up was for the diagnosis of allergic rhinitis at baseline (OR, 7.8; 95%CI, 3.1–20.0 in the model containing the covariates of rhinitis diagnosis, sex, second-hand smoke exposure, presence of pets at home, family history of allergic disorders, sensitization to Parietaria judaica; grass pollen; house dust mites; Olea europea: orchard; perennial rye; and cat allergens). Female sex, sensitization to Parietaria judaica and the presence of pets in the home were also significantly predictive of new onset asthma in the same model. Treatment with allergen immunotherapy was significantly and inversely related to the development of new onset asthma (OR, 0.53; 95%CI, 0.32–0.86).

In the present study we found that allergic rhinitis is an important independent risk factor for asthma. Moreover, treatment with allergen immunotherapy lowers the risk of the development of new asthma cases in adults with allergic rhinitis.

Wheeze, asthma diagnosis and medication use: a national adult survey in a developing country

BACKGROUND

As relatively little is known about adult wheeze and asthma in developing countries, this study aimed to determine the predictors of wheeze, asthma diagnosis, and current treatment in a national survey of South African adults.

METHODS

A stratified national probability sample of households was drawn and all adults (>14 years) in the selected households were interviewed. Outcomes of interest were recent wheeze, asthma diagnosis, and current use of asthma medication. Predictors of interest were sex, age, household asset index, education, racial group, urban residence, medical insurance, domestic exposure to smoky fuels, occupational exposure, smoking, body mass index, and past tuberculosis.

RESULTS

A total of 5671 men and 8155 women were studied. Although recent wheeze was reported by 14.4% of men and 17.6% of women and asthma diagnosis by 3.7% of men and 3.8% of women, women were less likely than men to be on current treatment (OR 0.6; 95% confidence interval (CI) 0.5 to 0.8). A history of tuberculosis was an independent predictor of both recent wheeze (OR 3.4; 95% CI 2.5 to 4.7) and asthma diagnosis (OR 2.2; 95% CI 1.5 to 3.2), as was occupational exposure (wheeze: OR 1.8; 95% CI 1.5 to 2.0; asthma diagnosis: OR 1.9; 95% CI 1.4 to 2.4). Smoking was associated with wheeze but not asthma diagnosis. Obesity showed an association with wheeze only in younger women. Both wheeze and asthma diagnosis were more prevalent in those with less education but had no association with the asset index. Independently, having medical insurance was associated with a higher prevalence of diagnosis.

CONCLUSIONS

Some of the findings may be to due to reporting bias and heterogeneity of the categories wheeze and asthma diagnosis, which may overlap with post tuberculous airways obstruction and chronic obstructive pulmonary disease due to smoking and occupational exposures. The results underline the importance of controlling tuberculosis and occupational exposures as well as smoking in reducing chronic respiratory morbidity. Validation of the asthma questionnaire in this setting and research into the pathophysiology of post tuberculous airways obstruction are also needed.

The crystal structure of recombinant proDer p 1, a major house dust mite proteolytic allergen

Allergy to house dust mite is among the most prevalent allergic diseases worldwide. Most house dust mite allergic patients react to Der p 1 from Dermatophagoides pteronyssinus, which is a cysteine protease. To avoid heterogeneity in the sample used for crystallization, a modified recombinant molecule was produced. The sequence of the proDer p 1 allergen was modified to reduce glycosylation and to abolish enzymatic activity. The resulting rproDer p 1 preparation was homogenous and stable and yielded crystals diffracting to a resolution of 1.61 A. The active site is located in a large cleft on the surface of the molecule. The 80-aa pro-peptide adopts a unique fold that interacts with the active site cleft and a substantial adjacent area on the mature region, excluding access to the cleft and the active site. Studies performed using crossed-line immunoelectrophoresis and IgE inhibition experiments indicated that several epitopes are covered by the pro-peptide and that the epitopes on the recombinant mature molecule are indistinguishable from those on the natural one. The structure confirms previous results suggesting a preference for aliphatic residues in the important P2 position in substrates. Sequence variations in related species are concentrated on the surface, which explains the existence of cross-reacting and species-specific antibodies. This study describes the first crystal structure of one of the clinically most important house dust mite allergens, the cysteine protease Der p 1.

Ethnic variations in incidence of asthma episodes in England & Wales: national study of 502,482 patients in primary care

BACKGROUND

Recent studies have demonstrated marked international variations in the prevalence of asthma, but less is known about ethnic variations in asthma epidemiology within individual countries and in particular the impact of migration on risk of developing asthma. Recent within country comparisons have however revealed that despite originating from areas of the world with a low risk for developing asthma, South Asian and Afro-Caribbean people in the UK are significantly (3x and 2x respectively) more likely to be admitted to hospital for asthma related problems than Whites.

METHODS

Using data from the Fourth National Study of Morbidity Statistics in General Practice, a one-percent broadly representative prospective cohort study of consultations in general practice, we investigated ethnic variations in incident asthma consultations (defined as new or first consultations), and compared consultation rates between those born inside and outside the UK (migrant status). Logistic regression models were used to examine the combined effects of ethnicity and migration on asthma incident consultations.

RESULTS

Results showed significantly lower new/first asthma consultation rates for Whites than for each of the ethnic minority groups studied (mean age-adjusted consultation rates per 1000 patient-years: Whites 26.4 (95%CI 26.4, 26.4); South Asians 30.4 (95%CI 30.3, 30.5); Afro-Caribbeans 35.1 (95%CI 34.9, 35.3); and Others 27.8 (27.7, 28.0). Within each of these ethnic groups, those born outside of the UK showed consistently lower rates of incident asthma consultations. Modelling the combined effects of ethnic and migrant status revealed that UK-born South Asians and Afro-Caribbeans experienced comparable risks for incident GP consultations for asthma to UK-born Whites. Non-UK born Whites however experienced reduced risks (adjusted OR 0.82, 95%CI 0.69, 0.97) whilst non-UK born South Asians experienced increased risks (adjusted OR 1.33, 95%CI 1.04, 1.70) compared to UK-born Whites.

CONCLUSION

These findings strongly suggest that ethnicity and migration have significant and independent effects on asthma incidence. The known poorer asthma outcomes in UK South Asians and Afro-Caribbeans may in part be explained by the offspring of migrants experiencing an increased risk of developing asthma when compared to UK-born Whites. This is the first study to find heterogeneity for incident asthma consultations in Whites by migrant status.

Asthma in Hispanics

Hispanic individuals trace their ancestry to countries that were previously under Spanish rule, including Mexico, large parts of Central and South America, and some Caribbean islands. Most--but not all--Hispanics have variable proportions of European, Amerindian, and African ancestry. Hispanics are diverse with regard to many factors, including racial ancestry, country of origin, area of residence, socioeconomic status, education, and access to health care. Recent findings suggest that there is marked variation in the prevalence, morbidity, and mortality of asthma in Hispanics in the United States and in Hispanic America. The reasons for differences in asthma and asthma morbidity among and within Hispanic subgroups are poorly understood but are likely due to the interaction between yet-unidentified genetic variants and other factors, including environmental tobacco smoke exposure, obesity, allergen exposure, and availability of health care. Barriers to optimal management of asthma in Hispanics in the United States and in Hispanic America include inadequate access to health care, suboptimal use of antiinflammatory medications, and lack of reference values for spirometric measures of lung function in many subgroups (e.g., Puerto Ricans). Future studies of asthma in Hispanics should include large samples of subgroups that are well characterized with regard to self-reported ethnicity, country of origin, place of birth, area of residence, and indicators of socioeconomic status. Because Hispanics are disproportionately represented among the poor in the United States, implementation of adequate access to health care and social reforms (e.g., improving housing conditions) would likely have a major impact on reducing asthma morbidity in this population.

Standard skin prick testing and sensitization to inhalant allergens across Europe--a survey from the GALEN network

Skin prick testing (SPT) is the standard method for diagnosing allergic sensitization but is to some extent performed differently in clinical centres across Europe. There would be advantages in harmonizing the standard panels of allergens used in different European countries, both for clinical purposes and for research, especially with increasing mobility within Europe and current trends in botany and agriculture. As well as improving diagnostic accuracy, this would allow better comparison of research findings in European allergy centres. We have compared the different SPT procedures operating in 29 allergy centres within the Global Allergy and Asthma European Network (GA(2)LEN). Standard SPT is performed similarly in all centres, e.g. using commercial extracts, evaluation after 15-20 min exposure with positive results defined as a wheal >3 mm diameter. The perennial allergens included in the standard SPT panel of inhalant allergens are largely similar (e.g. cat: pricked in all centres; dog: 26 of 29 centres and Dermatophagoides pteronyssinus: 28 of 29 centres) but the choice of pollen allergens vary considerably, reflecting different exposure and sensitization rates for regional inhalant allergens. This overview may serve as reference for the practising doctor and suggests a GA(2)LEN Pan-European core SPT panel.

A population-based study of asthma, quality of life, and occupation among elderly Hispanic and non-Hispanic whites: a cross-sectional investigation

BACKGROUND

The U.S. population is aging and is expected to double by the year 2030. The current study evaluated the prevalence of asthma and its correlates in the elderly Hispanic and non-Hispanic white population.

METHODS

Data from a sample of 3021 Hispanics and non-Hispanic White subjects, 65 years and older, interviewed as part of an ongoing cross-sectional study of the elderly in west Texas, were analyzed. The outcome variable was categorized into: no asthma (reference category), current asthma, and probable asthma. Polytomous logistic regression analysis was used to assess the relationship between the outcome variable and various socio-demographic measures, self-rated health, asthma symptoms, quality of life measures (SF-12), and various occupations.

RESULTS

The estimated prevalence of current asthma and probable asthma were 6.3% (95%CI: 5.3-7.2) and 9.0% (95%CI: 7.8-10.1) respectively. The majority of subjects with current asthma (Mean SF-12 score 35.8, 95%CI: 34.2-37.4) or probable asthma (35.3, 34.0-36.6) had significantly worse physical health-related quality of life as compared to subjects without asthma (42.6, 42.1-43.1). In multiple logistic regression analyses, women had a 1.64 times greater odds of current asthma (95%CI: 1.12-2.38) as compared to men. Hay fever was a strong predictor of both current and probable asthma. The odds of current asthma were 1.78 times (95%CI: 1.24-2.55) greater among past smokers; whereas the odds of probable asthma were 2.73 times (95%CI: 1.77-4.21) greater among current smokers as compared to non-smokers. Similarly fair/poor self rated health and complaints of severe pain were independently associated with current and probable asthma. The odds of current and probable asthma were almost two fold greater for obesity. When stratified by gender, the odds were significantly greater among females (p-value for interaction term = 0.038). The odds of current asthma were significantly greater for farm-related occupations (adjusted OR = 2.09, 95%CI: 1.00-4.39); whereas the odds were significantly lower among those who reported teaching as their longest held occupation (adjusted OR = 0.36, 95%CI = 0.18-0.74).

CONCLUSION

This study found that asthma is a common medical condition in the elderly and it significantly impacts quality of life and general health status. Results support adopting an integrated approach in identifying and controlling asthma in this population.

Current asthma and respiratory symptoms among pupils in relation to dietary factors and allergens in the school environment

The aim was to study asthma and allergy in relation to diet and the school environment. Pupils (5-14 years) in eight schools received a questionnaire, 1014 participated (68%). Settled dust was collected on ALK-filters and analyzed for allergens from cat (Fel d 1), dog (Can f 1), horse (Equ cx), house dust mites (Der p 1, Der f 1), and cockroach (Bla g 1) by ELISA. In total, 6.8% reported cat allergy, 4.8% dog allergy, 7.7% doctor's diagnosed asthma and 5.9% current asthma, and 7.8% reported wheeze. Current asthma was less common among those consuming more fresh milk (P < 0.05) and fish (P < 0.01). Poly-unsaturated fatty acids was associated with more wheeze (P < 0.05), olive oil was associated with less doctors' diagnosed asthma (P < 0.05). Totally, 74% of the classrooms had mean CO(2) <1000 ppm. The median concentration per gram dust was 860 ng/g Fel d 1, 750 ng/g Can f 1 and 954 U/g Equ cx. Horse allergen was associated with more wheeze (P < 0.05), daytime breathlessness (P < 0.05), current asthma (P < 0.05) and atopic sensitization (P < 0.05). Dog allergen was associated with wheeze (P < 0.05) and daytime breathlessness (P < 0.05). The associations between allergens and respiratory symptoms were more pronounced among those consuming margarine, not consuming butter, and with a low intake of milk. In conclusion, cat, dog and horse allergens in schools could be a risk factor for asthma and atopic sensitization, and dietary factors may interact with the allergen exposure.

PRACTICAL IMPLICATIONS

Previous school studies performed by us in mid-Sweden, showed that most classrooms did not fulfill the ventilation standards. In this study, most of the classrooms fulfilled the ventilation standard, but despite that had widespread allergen contamination. Most previous studies have focused on cat allergen, but our study has shown that also dog and horse allergens can be risk factors for asthma and allergy in schools. As allergens are transported from other environments, mainly the home environment, the main prevention should be to minimize transfer of allergens. This could be achieved by reducing contacts with furry pets and horses, or using different clothes at home and at school (e.g. school uniforms). Increased cleaning in the schools may reduce allergen levels, but the efficiency of this measure must be evaluated in further intervention studies. Finally, our study supports the view that dietary habits among pupils should not be neglected and interaction between dietary factors and indoor allergen exposure needs to be further investigated.