ArticlePDF Available

Hyperreactive airway disease prevalence and correlates in adults: data from a cross-sectional national study in Lebanon

Authors:

Abstract

Background: Asthma and hyperreactive airway (HRA) disease are a major cause of health resource utilization and poor quality of life worldwide; its prevalence in adults may widely vary according to the definition used. It is mainly a childhood disease, but its natural history till adulthood is not well known. This is due to other confounding factors such as smoking and environmental factors that may lead to misdiagnose asthma as chronic obstructive pulmonary disease. Correct and timely diagnosis of asthma and HRA is important because it can be treated successfully and affected individuals may achieve good control of their disease. Objective: To evaluate the prevalence of asthma and HRA in Lebanese adults, their symptoms and predictors. Methods: A cross-sectional study using a multistage cluster sample was carried out in Lebanon, between October 2009 and September 2010.Lebanese residents aged 40 and above participated to the study; a post-bronchodilator spirometry was performed to confirm diagnosis. Results: Out of 2201 individuals, 218 (99%) were considered to have HRA. The following factors were found associated with HRA in the Lebanese population: Northern (ORa: 3.54) and Bekaa Plain (ORa: 2.44)] versus other regions; occupational exposure to toxic gases and fumes (ORa: 2.08); heating home with wood (ORa: 1.75); having a family history of chronic respiratory disease (ORa: 2.19), a history of childhood lung problem (ORa: 5.53), and father smoking during childhood (ORa: 1.47). Added to these factors, HRA was also predicted by female gender (ORa: 1.81); lower education (ORa: 120); older age (ORa: 1.28) and low birth weight (ORa: 3.14). Conclusion: This is the first epidemiological study in Lebanon that determined physician diagnosed asthma prevalence and hyperreactive airway disease and their associated factors among Lebanese adults. It also provides useful contributions that local health organizations may use for national programming and a foundation for health researchers to pursue further study in asthma research. Public awareness about the increased risk of asthma associated with heating homes with wood and exposure to passive smoking should be raised; Lebanese policy makers should also generate higher efforts to implement and reinforce the smoking ban law in public places.
A preview of the PDF is not available
... In Lebanon, previous studies have assessed asthma prevalence in specific age groups, mainly among students 3-15 [10], 5-12 [11], or 13-14 years old [12], and adults 40 years of age or older [13]. Other studies have explored correlated factors [14][15][16][17][18], but to our knowledge, none has assessed asthma prevalence at the national level, and by including adults 16 years old or above. ...
... Although it is not reliable to compare the prevalence of asthma in adults to that found among children, we believe that recently there is an increase in physicians' awareness of asthma disease in Lebanon. Additionally, a previous study had reported a prevalence of physiciandiagnosed asthma among Lebanese adults 40 years old or above of 4.6% in 2014 [13]. Lebanon has suffered from rising pollution, especially after the waste crisis in 2015, All values are expressed as n (%) except for age which is expressed a n (mean ± SD) SD standard deviation, CCS Current cigarette smokers, CWS current waterpipe smokers, PCS previous cigarette smokers, PWS previous waterpipe smokers which might explain this increase in the prevalence of asthma among adults. ...
... Although our prevalence is within the range reported from surrounding countries, possible interpretations of the variation include the changing in the definition of current asthma across many study settings and the effect of gene-environment interactions [35]. A study conducted among Lebanese adults 40 years or above reported a prevalence of hyperreactive airways at 9.9% [13]. In our study, the prevalence of current asthma was estimated according to the most up-to-date definition; therefore, we believe that it reflects the real situation among Lebanese adults. ...
Article
Full-text available
Background: No national research has yet explored the prevalence of asthma among adults in Lebanon. This study aims to evaluate the prevalence of physician-diagnosed asthma and current asthma, and their determinants among Lebanese adults 16 years old or above. Methods: A cross-sectional study was carried out using a multistage cluster sampling. The questionnaire used collected information on asthma, respiratory symptoms, and risk factors. Results: The prevalence of physician-diagnosed asthma was 6.7% (95%CI: 5-8.7%), and that of current asthma was 5% (95%CI: 3.6-6.9%). Chronic symptoms such as cough, wheezing, and shortness of breath were worst at night. Factors positively associated with physician-diagnosed asthma were a secondary educational level (adjusted OR, aOR=4.45), a family history of chronic respiratory diseases (aOR=2.78), lung problems during childhood (15.9), and allergic rhinitis (4.19). Additionally, consuming fruits and vegetables less than once per week (3.36), a family history of chronic respiratory diseases (3.92), lung problems during childhood (9.43), and allergic rhinitis (8.12) were positively associated with current asthma. Conclusions: The prevalence of asthma was within the range reported from surrounding countries. However, repeated cross-sectional studies are necessary to evaluate trends in asthma prevalence in the Lebanese population.
... SES in terms of education, wealth and employment influences people's exposure and vulnerability to disease, as well as healthcare outcomes and social consequences of having a chronic disease (Kaplan 2001;Daniel 2008;Evans et al. 2001). Epidemiological studies in the Middle East region confirm the relation between SES and chronic disease such as hypertension, cardiovascular disease, diabetes and asthma (Salame et al. 2014;Zabaneh et al. 2008;Shah et al. 2010;Jackson et al. 2002;Abukhdeir et al. 2013;Christos et al. 2014). ...
... The relation between low education and a greater burden of chronic disease was also found in studies from Syria, Iran (Boutayeb et al. 2013), Lebanon (Salame et al. 2014;Zabaneh et al. 2008) and Qatar (Christos et al. 2014). ...
Article
Objectives: The study investigated the association between socio-economic status (SES) and self-reported chronic disease (CD) among the Palestinian population in the Occupied Palestinian Territory, and whether this association was similar in the refugee camps. Methods: We used data from representative samples in 2006 and 2010 collected by the Palestinian Central Bureau of Statistics. SES was defined by education, wealth and employment status. Associations between SES and CD were analysed and stratified by living in or outside refugee camps. Results: CD prevalence increased among men and decreased among women in all SES categories and the Odds Ratio for CD was higher inside than outside the refugee camps, except for women in 2006. In both 2006 and 2010 the odds ratio of CD was higher among the lowest SES groups. The pattern of the negative association between SES and CD was similar in and outside the refugee camps. Conclusions: We found that the highest burden of CD is among those with low SES. In spite of a higher CD Odds Ratio in the refugee camps, the pattern of association between SES and CD did not differ in the refugee camps.
... Penelitian GARCIA-ARCOS dkk. menunjukkan bahwa nikotin aerosol meningkatkan hiperreaktivitas jalan napas yang memicu bronkospasme yaitu penyempitan jalan masuknya udara di jalan napas (Reinikovaite et al., 2018), (Salamé et al., 2014). Hal ini diperparah juga oleh efek nikotin terhadap parasimpatis di paru sehingga memicu peningkatan resistensi saluran nafas (Menshov et al., 2022). ...
Article
Full-text available
Rokok elektrik menarik banyak peminat karena dipasarkan menjadi salah satu alternatif perokok untuk berhenti merokok. Rokok elektrik merupakan alat yang memanaskan larutan dengan kandungan nikotin , air, propilen glikol, gliserin menjadi uap yang akan dihirup oleh pengguna. Uap ini mengandung banyak bahan kimia yang mempengaruhi paru yang merupakan organ pertama yang terpapar uap tersebut. Paru selain berfungsi untuk respirasi juga berperan dalam mengatur keseimbangan asam basa yaitu jika ph tubuh meningkat atau lebih alkalosis maka laju pernafasan akan menurun sehingga lebih banyak karbondioksida dalam darah dan ph akan menurun bertahap menjadi normal begitu juga sebaliknya. Fungsi paru ini tergantung pada struktur paru termasuk sel di paru , surfaktan, alveolus. Tujuan penelitian untuk menjelaskan pengaruh asap rokok elektrik terhadap keseimbangan asam basa di tubuh manusia. Artikel membahas bahan yang selalu ada di asap rokok elektrik yaitu nikotin , gliserin atau propilen glikol , logam. Beberapa jurnal dan artikel yang meneliti efek dari bahan larutan rokok elektrik terhadap organ paru khususnya. Beberapa penelitian menunjukkan efek bahan kimia di asap rokok elektrik yang memicu hipoksia, hiperkarbia dan gangguan keseimbangan asam basa di tubuh manusia Penelitian secara biomolekuler diperlukan untuk mengetahui efek bahaya dalam asap rokok elektrik khususnya pada organ paru.
... Asthma is a leading cause of morbidity with a global prevalence of approximately 300 million and is expected to increase to 400 to 450 million people worldwide by 2025 [1]. In Lebanon, the prevalence of asthma has been estimated at 9% in 2014 [2] and at 6.7% in 2021 [3]. Despite the availability of multiple therapeutic options, 5-10% of asthmatic patients experience severe disease associated with substantial morbidity. ...
Article
Full-text available
Background The prevalence of eosinophilic asthma in Lebanon, one of the most severe phenotypes among severe asthma, is not known. This study aimed at determining the prevalence of the eosinophilic phenotype defined as an eosinophil count ≥ 300 cells/mm ³ among severe asthma patients in Lebanon. Methods The Lebanese Chapter of the PREPARE study was a national, multicenter, cross-sectional observational study. Patients aged ≥ 12 years with severe asthma were identified and prospectively enrolled during clinic visits and completed the Global Initiative for Asthma (GINA) assessment of asthma control questionnaire. Patients’ health characteristics were collected from medical records and blood samples were obtained for measurement of serum IgE levels and blood eosinophils count. Results Overall, 101 patients (with mean age of 46.3 ± 17.0 years and 73.27% females) with severe asthma were included and, among them, 37% had eosinophilic phenotype, 67.3% had atopic phenotype with IgE > 100 IU/mL and 25.7% patients had overlapping atopic and eosinophilic phenotypes. Close to 80% had late-onset asthma, beyond 12 years of age, and around 85% had at least one severe exacerbation in the 12 months prior to study enrolment. The majority of participants [64.4%] had uncontrolled asthma, 24.7% had partially controlled symptoms and 10.9% had controlled symptoms. 19.8% of participants were on chronic oral corticosteroids, 78.2% had short course treatment of corticosteroids and all were prescribed a combination of inhaled corticosteroids and long-acting beta-agonist. Conclusions The majority of patients with severe asthma were uncontrolled of which 37% present with an eosinophilic phenotype, which should be taken into consideration for better management of these patients in view of the novel phenotype-specific therapeutic options.
... The prevalence of asthma in Lebanese adults, expressed as the prevalence of hyper-reactive airways is estimated at 9% [3]. While effective asthma treatment is available, a meta-analysis including 300 million patients found that 20% of patients worldwide had severe illness despite adequate treatment [4]. ...
Article
Full-text available
Background Studies exploring the association between weight and asthma are not conclusive. Both obesity and asthma have been increasing in Lebanon, their association is not yet documented. The aim of this study is to explore the effect of weight on asthma control in adults. Methods This is a cross-sectional study, involving all consecutive asthma patients presenting to the outpatient allergy clinic at the Hotel-Dieu de France (HDF) University Hospital between January 1, 2014 and December 30, 2016. Patients included were those who consented to fill the Asthma Control Test (ACT) after 3 months of therapy. BMI was reported at the same time of the questionnaire. Results A total of 183 records of diagnosed asthma cases in adults were included. Sixty-three (34.4%) were males and 120 (65.6%) females, with a mean age of 38.5 (SD = 14.3). Ninety patients (49.2%) were of normal weight, 65 (35.5%) overweight and 28 (15.3%) obese. Seventy-one percent had an ACT score ≤ 19, which corresponds to poor asthma control. Patients who were overweight or obese were more likely to have poor asthma control compared to patients who had a normal weight at the time of evaluation. Conclusion In conclusion, our study showed a significant association between asthma control as assessed by the ACT and high BMI defining overweight or obesity. This is the first national study exploring the association between asthma and overweight/obesity in Lebanon. A larger study with sampling from different specialists’ sites is needed to draw more conclusions about this association.
... Reactive Airway Disease (RAD) is the next commonest childhood disease that was seen in the study with a prevalence of 18%. Salame et al. [25] noted a whooping prevalence of 99.9%. Though his study was among adult population in a Lebanese community and not a hospital setting. ...
Article
Full-text available
Background: Pattern and distribution of common pediatric illnesses are issues often reported in government and teaching hospitals, but very few are reported from private settings. Objective: To determine the pattern and prevalence of common pediatric diseases presenting at a private pediatric specialist hospital. Material and methods: This is a hospital based descriptive cross sectional study of children seen in a private hospital from March 2012-March 2014. In all, 2942 patients were studied as seen. Diagnosis of the pediatric illnesses was made based on painstaking history taking, physical examination and thorough investigations including blood film reports, full blood counts, chest X rays, blood cultures, urine microscopy and cultures when necessary and affordable. Patients were managed according to their diagnoses. Data analysis was done using SPSS version 20. Data was summarized using percentages and comparisons subjected to χ² analysis with p at <0.05 as significant. These are presented in tables. Results: There were 1636 (55.6%) male patients and 1306 (44.4%) female patients. Most frequent presenting age group were those aged 0-12 months 1424 (48.4%). Malaria was most frequently found pediatric illness 737 (25%) followed by Reactive airway disease (RAD) 529 (18.0%), diarrhea disease 150 (5.1%), Sepsis 66 (2.2%), UTI 58 (2.0%), Pneumonia 22 (0.8%) and URTI 20 (0.7%), a good number were comorbidities and constituted 864 (29.4%) of the presentations. Conclusion: Malaria is the most prevalent illness noted in the study however early and accurate diagnosis of reactive airway disease will help to avert numerous complications that may follow its misdiagnosis and administration of wrong treatment.
... Its severity is assessed by pulmonary function test, symptom frequencies and exacerbation rate as well as rescue inhaler use (24). It is mainly a childhood disease although it is too hard to know its precise definition and prevalence in adults (25 any other region in the world (1). They found no difference between the sexes in this matter, as also noted in our study. ...
Article
Full-text available
Background Asthma, involving 5–10% of global population, has a heterogeneous distribution in the community regardless of age and its prevalence and incidence tend to grow worldwide as reported by many recent epidemiologic surveys. Materials and Methods The present study aimed to survey the prevalence of asthma symptoms in Tehran as the first attempt in terms of situation analysis of the disease in the Iranian society by using relevant parts of the European Community Respiratory Health Survey (ECRHS) questionnaire. Results Wheezing was reported in 48% of males and 34% of females in the age range of 20–44 years, around 50% of which was associated with breathlessness or cold., the people who answered “yes” to the questions 1 (wheezing), 4 (coughing), 5 (asthma history) or 7 (nasal allergy) were totally 211 among whom 124 (58.8%) were males and the rest (41.2%) were females. Conclusion Asthma symptoms decrease the quality of life and impose high costs on the healthcare system in many countries. A low rate of participants had been informed about their asthma by physicians and not all of them were taking medications. Risk factor analysis and control is strongly advised in order to lessen the prevalence of the disease and symptoms. Air pollution, smoking, unhealthy life style and many personal and social factors need to be assessed and eliminated. It seems that a- second phase- ECRH survey should be conducted to assess the situation of asthma through population of Tehran.
Article
Objective: This survey aimed to understand the physicians’ practice pattern and challenges faced while treating their patients with asthma in five countries-Malaysia, Nepal, Myanmar, Morocco and Lebanon. Methods: Questionnaire-based data was gathered from internal medicine doctors (209), general practitioners (206), chest physicians (152) and pediatricians (58) from 232 locations from across the five countries. Results: Of the 816 physicians, 374 physicians encountered at least 5 asthma patients daily. Approximately, 38% physicians always used spirometry for diagnosis and only 12% physicians always recommended Peak flow meter (PFM) for home-monitoring. Salmeterol/fluticasone (71%) followed by formoterol/budesonide (38%) were the most preferred ICS/long-acting beta2-agonists (LABA); Salbutamol (78%) was the most preferred reliever medication. 60% physicians said >40% of their patients were apprehensive to use inhalers. 72% physicians preferred a pressurized metered-dose inhaler (pMDI) to a dry powder inhaler (DPI) with only a third of them using a spacer with the pMDI. 71% physicians believed that using similar device for controller and reliever can be beneficial to patients. Skipping medicines in absence of symptoms (64%), incorrect inhaler technique (48%) and high cost of medication (49%) were considered as major reasons for non-adherence by most physicians. Incorrect inhaler technique (66%) and nonadherence (59%) were considered the most common causes of poor asthma control. Conclusions: There are opportunities to improve the use of diagnostic and monitoring tools for asthma. Non-adherence, incorrect inhaler technique and cost remain a challenge to achieve good asthma control. Asthma education, including correct demonstration of inhaler, can potentially help to improve inhaler adherence.
Article
Full-text available
Introduction: Obesity has a high prevalence in Lebanon adolescents, but nothing is known about children obesity. Our objective was to evaluate obesity and its related behaviour in school children. Methods: This is a cross-sectional pilot study that assessed nutritional behaviour, physical activity and hobbies of 1268 children, stressing on differences between males andfemales. Results: Boys have a trendfor a higher obesity than girls in Lebanon; however, they are less likely to adopt nutritional behaviours that maintain or decrease weight. Nevertheless, girls prefer activities that are associated with higher obesity, while boys prefer those that prevent obesity. Conclusion: Our results are similar to those of other researchers. Further studies are necessary to confirm the results obtained in this study.
Article
Full-text available
Although Lebanon is a highly polluted country, so far no study has specifically been designed to assess the association between outdoor air pollution and chronic bronchitis in this country. To assess the association between exposure to outdoor air pollution and chronic bronchitis in Lebanon. A pilot case-control study was conducted in two tertiary care hospitals. Cases consisted of patients diagnosed with chronic bronchitis by a pulmonologist and those epidemiologically confirmed. Controls included individuals free of any respiratory signs or symptoms. After obtaining informed consent, a standardized questionnaire was administered. Bivariate, stratified (over smoking status and gender) and multivariate analyses revealed that passive smoking at home (ORa: 2.56, 95% CI: 1.73-3.80) and at work (ORa: 1.89, 95% CI: 1.13-3.17); older age (ORa: 1.75, 95% CI: 1.55-2.39); lower education (ORa: 1.44, 95% CI: 1.21-1.72); living close to a busy road (ORa: 1.95, 95% CI: 1.31-2.89) and to a local power plant (ORa: 1.62, 95% CI: 1.07-2.45); and heating home by hot air conditioning (ORa: 1.85, 95% CI: 1.00-3.43) were moderately associated with chronic bronchitis; an inverse association was found with heating home electrically (ORa: 0.58, 95% CI: 0.39-0.85). A positive dose-effect relationship was observed in those living close to a busy road and to a local diesel exhaust source. Chronic bronchitis is associated with outdoor air pollution.
Article
Full-text available
No population study has explored the population distribution of adult asthma in the United Arab Emirates (UAE). The objective is to estimate asthma prevalence in general population in UAE. Using standard European Community Respiratory Health Survey (ECRHS) questionnaires and tools, this is a cross-sectional assessment of a random sample of the population in established quotas of the seven Emirates in the UAE. We surveyed 1,220 participants, of which 63.2% were male, and 20.1% were UAE Nationals, with a mean (SD) age of 32.9 (14.1) years. Prevalence of individual respiratory symptoms from the ECRHS screening questionnaire in all participants were generally ranging 8 - 10%, while participants 20-44 years presented lower prevalence in all symptoms (p < 0.05). The expected male:female ratio of reported wheezing and asthma attacks and its treatment by age was not observed. Participating women reported more individual symptoms than men. Overall, there were 15.4% (95% C.I. 13.5 - 17.5) participants who fulfilled our screening criteria for asthma, while for consistency with ECRHS, there were 12.1% (95% C.I. 10.4 - 14.1) participants who fulfilled the ECRHS asthma definition, being 9.8% (95% C.I. 7.8 - 12.2) of those 20-44 years, that is 8.6% of male and 11.8% of female young adults participating. We conclude that asthma is common in the UAE, and gender differences are not observed in reported asthma symptoms in young adults. This being the first population based study exploring the prevalence of asthma and its determinants in the United Arab Emirates based on the ECRHS.
Article
Full-text available
Chronic obstructive pulmonary disease (COPD) continues to increase worldwide. The objective of this study was to determine the prevalence of COPD in Lebanese adults. A cross-sectional study was carried out using a multistage cluster sample from all over Lebanon. Residents aged 40 years and over were enrolled. Subjects underwent baseline spirometry and answered a questionnaire. After an albuterol + ipratropium bromide bronchodilator, a posttest was performed. Of 2201 individuals, only 33.3% had never smoked. The prevalence of COPD by the Global Initiative for Chronic Obstructive Lung Disease definition, was 9.7% (95% confidence interval [CI]: 8.5%-10.9%). According to the 5% lower limit of normal definition of COPD, the prevalence was 12.5% (95% CI: 11.2%-13.9%). A total of 20.2% were already diagnosed by a physician. No differences in symptoms across stages of COPD were found, but there was a significant trend for a higher number of visits to the emergency room and to the doctor (P < 0.001), and a higher number of hospitalizations (P < 0.001). Older individuals had an increased risk of COPD (adjusted odds ratio [OR(a)] = 1.05); so did "ever" cigarette smokers (OR(a) = 4.88) and water-pipe smokers (OR(a) = 2.53). This is the first epidemiological study in Lebanon that determined COPD prevalence and the link with water-pipe smoking.
Article
Full-text available
Asthma is a major cause of disability, health resource utilization and poor quality of life world-wide. We set out to generate estimates of the global burden of asthma in adults, which may inform the development of strategies to address this common disease. The World Health Survey (WHS) was developed and implemented by the World Health Organization in 2002-2003. A total of 178,215 individuals from 70 countries aged 18 to 45 years responded to questions related to asthma and related symptoms. The prevalence of asthma was based on responses to questions relating to self-reported doctor diagnosed asthma, clinical/treated asthma, and wheezing in the last 12 months. The global prevalence rates of doctor diagnosed asthma, clinical/treated asthma and wheezing in adults were 4.3%, 4.5%, and 8.6% respectively, and varied by as much as 21-fold amongst the 70 countries. Australia reported the highest rate of doctor diagnosed, clinical/treated asthma, and wheezing (21.0%, 21.5%, and 27.4%). Amongst those with clinical/treated asthma, almost 24% were current smokers, half reported wheezing, and 20% had never been treated for asthma. This study provides a global estimate of the burden of asthma in adults, and suggests that asthma continues to be a major public health concern worldwide. The high prevalence of smoking remains a major barrier to combating the global burden of asthma. While the highest prevalence rates were observed in resource-rich countries, resource-poor nations were also significantly affected, posing a barrier to development as it stretches further the demands of non-communicable diseases.
Article
Standardized procedures have been developed for use in epidemiological studies of relatively large population groups. Investigations of this type often require field studies carried on at a distance from traditional research laboratories. To obtain adequate data with a minimum of bias in such studies, which involve large numbers of subjects, time limitations, unavailability of sophisticated equipment, and a multiplicity of observers, simple and reliable standardized procedures are needed. In some respects, epidemiological studies serve as screening procedures. Performed initially or cross-sectionally, they determine the prevalence of symptoms, status of pulmonary function, and similar situations at one point in time. Repeated, using the same population at a later point in time, they serve as prospective or longitudinal studies and can then determine incidence of disease or give information regarding the progression of illness. Data required for epidemiological studies may differ from those required for clinical studies, which are diagnostic and directed toward individuals rather than groups. In clinical studies, much more detailed information about an individual may be required to assure correct diagnosis. This report does not deal with population selection or numbers of subjects. These topics were the subjects of an earlier report from a Committee on Standards for Epidemiological Survey in Chronic Respiratory Disease of the American Thoracic Society (ATS), published in 1969. Reference should be made to that document, which complements this presentation. Here we are concerned with how and when to use standard questionnaires on respiratory symptoms, tests of pulmonary function, and chest radiographs.
Article
The present study investigated the relationship between socioeconomic status, using measures of occupational class and education level, and the prevalence and incidence of asthma (with and without atopy) and chronic bronchitis using data from the European Community Respiratory Health Survey (ECRHS). Asthma and chronic bronchitis were studied prospectively within the ECRHS (n = 9,023). Incidence analyses comprised subjects with no history of asthma or bronchitis at baseline. Asthma symptoms were also assessed as a continuous score. Bronchitis risk was associated with low educational level (prevalence odds ratio (POR) 1.9; 95% confidence interval (CI) 1.4-2.8) and occupational class (1.8; 1.2-2.7). Incident bronchitis also increased with low educational level (risk ratio (RR) 2.8; 95%CI 1.5-5.4). Prevalent and incident asthma with no atopy were associated with low educational level. Subjects in the low occupational class (incident risk ratio (IRR) 1.4; 95%CI 1.2-1.7) and education group (IRR 1.3; 95% CI 1.1-1.6) had higher mean asthma scores than those in higher socioeconomic groups. Lower educational level was associated with increased risk of prevalent and incident chronic bronchitis and asthma with no atopy. Lower socioeconomic groups tended to have a higher prevalence and incidence of asthma, particularly higher mean asthma scores. Adjustment for variables associated with asthma and bronchitis explained little of the observed health differences by socioeconomic status.
Article
The rates of asthma and allergy (Type 1 hypersensitivity disorders) have been increasing worldwide for the last few decades. Various theories have been proposed to account for this alarming trend. One of these is the impact of environmental toxicants. Epidemiological research has correlated exposure to environmental chemicals (such as pesticides, solvents, and air pollutants) with increasing rates of both asthma and allergies. Research has documented chemicals as causal agents capable of producing immune system imbalances characteristic of type 1 hypersensitivity. In vitro studies and in vivo animal models have demonstrated that many of the environmental chemicals and pollutants that have been epidemiologically associated with increased allergic tendency have been shown to enhance Type 2 helper T cell (Th2) dominance, which is consistent with the T-helper cell pattern found in asthma, allergic rhinitis, and other Type 1 hypersensitivity disorders. Depletion of glutathione is one possible mechanism for this T-helper cell imbalance. Preliminary evidence suggests the possibility that repletion of glutathione levels (with oral supplementation of N-acetylcysteine), and enhancement of glutathione transferase function (using sulforaphanes), might be therapeutic options for countering type 1 hypersensitivity disorders caused by environmental chemicals.
Article
International reviews suggest that the median proportion of adult cases of asthma attributable to occupational exposure is between 10% and 15%. Therefore, it is essential that clinicians have a broad knowledge of the various causes associated with occupational asthma. Occupational asthmagens are categorized as low-molecular-weight (LMW, ≤1000 kd) and high-molecular-weight (HMW, ≥1000 kd) antigens. The purpose of this article is to review the most common representative LMW and HMW causes of occupational asthma over the past 70 years, with specific emphasis on newer causes reported over the past 5 years.