Occupational exposure to immunologically active agents and risk for lymphoma: The European Epilymph case–control study

ObjectivesAllergies and asthma may be protective for the development of lymphoma. We evaluated whether occupational allergens that provoke immune reactivity and asthma through an IgE-mediated pathway are protective for lymphoma.MethodsThe Epilymph study includes histologically or cytologically confirmed Hodgkin, B-cell, and T-cell lymphoma cases from six European countries (Spain, France, Germany, Italy, Ireland, and Czech Republic) recruited in 1998–2004. Controls were frequency matched to cases by age, gender, and study centre. Lifetime occupational exposure to seven high molecular weight (HMW) agents was evaluated through an asthma-specific job-exposure matrix. 2205 lymphoma cases and 2296 controls with complete occupational history could be included in the analysis. Associations between HMW exposures and lymphoma were evaluated using pooled unconditional logistic regression analyses.ResultsIndividuals exposed to HMW agents had a non-statistically significant decreased risk of any lymphoma (OR, 0.88: 95% CI, 0.74–1.05) and of B-cell lymphoma (OR, 0.91; 95% CI, 0.76–1.09), and a significantly decreased risk for Hodgkin lymphoma (OR, 0.62; 95% CI, 0.40–0.98). A decrease in risk for lymphoma was found for exposure to latex (OR, 0.74; 95% CI, 0.55–0.99).ConclusionsFurther epidemiologic and mechanistic research is needed to confirm that occupational exposure to HMW agents predisposing to asthma can reduce the risk of lymphoma.     

Use of induced sputum in the investigation of occupational asthma

The diagnosis of occupational asthma relies mainly on the demonstration of changes in airway calibre and airway responsiveness after exposure to occupational agents in the laboratory or at the workplace. However, spirometry or peak expiratory flow measurements may be open to misinterpretation when they are not performed optimally. As in non-occupational asthma, airway inflammation is one of the main characteristics of occupational asthma. Induced sputum, a non invasive method to assess airway inflammation, has been successfully used in the management of asthma. This article reviews the studies that have investigated and characterized the changes in sputum cell counts occurring in subjects with occupational asthma after exposure to occupational agents in the laboratory or at the workplace in order to assess the place of induced sputum in the investigation of occupational asthma. It also reviews the use of induced sputum during the follow-up of workers with occupational asthma after removal from exposure. This article also describes a new condition identified thanks to the use of induced sputum : occupational eosinophilic bronchitis. In conclusion, induced sputum is a useful tool in the investigation of occupational asthma. Its use on a regular basis in the investigation of occupational asthma also allows for the possibility of diagnosis of overlooked conditions such as occupational eosinophilic bronchitis. Its role in the surveillance of workers at risk to develop occupational asthma remains to be determined.     

Diagnosing occupational asthma: insight from induced sputum

The diagnosis of occupational asthma needs to be made objectively using as many criteria as possible. The latter include laboratory exposure tests with occupational agent(s), which are only available in specialized centers. Another approach is to monitor peak expiratory flow (PEF) and (or) methacholine airway responsiveness during periods at work and away from work. However, these measurements are open to misinterpretation when they are not optimally performed. Airway inflammation is one of the main characteristics of asthma. Induced sputum, a non-invasive method to assess airway inflammation, has been successfully used in the management of asthma. However, airway inflammation is seldom assessed during the investigation of occupational asthma. This article reviews the studies that have investigated and characterized the changes in sputum cell counts occurring in subjects with occupational asthma after exposure to occupational agents in the laboratory, or at the workplace to assess to place of induced sputum in the investigation of occupational asthma.     

Occupational Injuries in Germany: Population-Wide National Survey Data Emphasize the Importance of Work-Related Factors

Unintentional injuries cause much of the global mortality burden, with the workplace being a common accident setting. Even in high-income economies, occupational injury figures remain remarkably high. Because risk factors for occupational injuries are prone to confounding, the present research takes a comprehensive approach. To better understand the occurrence of occupational injuries, sociodemographic factors and work- and health-related factors are tested simultaneously. Thus, the present analysis aims to develop a comprehensive epidemiological model that facilitates the explanation of varying injury rates in the workplace. The representative phone survey German Health Update 2010 provides information on medically treated occupational injuries sustained in the year prior to the interview. Data were collected on sociodemographics, occupation, working conditions, health-related behaviors, and chronic diseases. For the economically active population (18–70 years, n = 14,041), the 12-month prevalence of occupational injuries was calculated with a 95% confidence interval (CI). Blockwise multiple logistic regression was applied to successively include different groups of variables. Overall, 2.8% (95% CI 2.4–3.2) of the gainfully employed population report at least one occupational injury (women: 0.9%; 95% CI 0.7–1.2; men: 4.3%; 95% CI 3.7–5.0). In the fully adjusted model, male gender (OR 3.16) and age 18–29 (OR 1.54), as well as agricultural (OR 5.40), technical (OR 3.41), skilled service (OR 4.24) or manual (OR 5.12), and unskilled service (OR 3.13) or manual (OR 4.97) occupations are associated with higher chances of occupational injuries. The same holds for frequent stressors such as heavy carrying (OR 1.78), working in awkward postures (OR 1.46), environmental stress (OR 1.48), and working under pressure (OR 1.41). Among health-related variables, physical inactivity (OR 1.47) and obesity (OR 1.73) present a significantly higher chance of occupational injuries. While the odds for most work-related factors were as expected, the associations for health-related factors such as smoking, drinking, and chronic diseases were rather weak. In part, this may be due to context-specific factors such as safety and workplace regulations in high-income countries like Germany. This assumption could guide further research, taking a multi-level approach to international comparisons.     

Comorbidities are associated with different features of severe asthma

Background

According to ATS/ERS document on severe asthma (SA), the management of these patients requires the identification and proper treatment of comorbidities, which can influence the control of asthma.

Methods

The aim of this study was to assess the independent effect of different comorbidities on clinical, functional and biologic features of SA. Seventy-two patients with SA according to GINA guidelines were examined. We collected demographic data, smoking habit, asthma history, and assessment of comorbidities. Pulmonary function, inflammatory biomarkers, upper airway disease evaluation, asthma control and quality of life were carefully assessed.

Results

The mean age of patients was 59.1 years (65.3% female, 5.6% current smokers). Comorbidities with higher prevalence were: chronic rhinosinusitis with or without nasal polyps (CRSwNP or CRSsNP), obesity and gastro-esophageal reflux (GERD), with some overlapping among them. In an univariate analysis comparing patients with single comorbidities with the other ones, asthmatics with CRSwNP had lower lung function and higher sputum eosinophilia; obese asthmatics had worse asthma control and quality of life, and tended to have lower sputum eosinophils; asthmatics with GERD showed worse quality of life. In multivariate analysis, obesity was the only independent factor associated with poor asthma control (OR 4.9), while CRSwNP was the only independent factor associated with airway eosinophilia (OR 16.2). Lower lung function was associated with the male gender and longer duration of asthma (OR 3.9 and 5.1, respectively) and showed a trend for the association with nasal polyps (OR 2.9, p?=?0.06).

Conclusion

Our study suggests that coexisting comorbidities are associated with different features of SA.

     

Prevention of occupational asthma in Ontario

Occupational asthma continues to be one of the most common occupational lung diseases in industrialized areas. Primary and secondary preventive measures have been well described, but there are relatively few studies to support the effectiveness of such measures, although the benefits of tertiary measures such as early recognition and removal from further exposure to a causative sensitizing agent are well recognized. In Ontario, a combined approach of preventive measures has shown effectiveness in allergy and asthma from occupational exposure to natural rubber latex. In addition, a program to reduce exposure to diisocyanates and introduce medical surveillance was associated with earlier diagnosis and fewer cases in a compensation population. However there remain barriers to the early diagnosis of occupational asthma in Ontario, especially in workers of lower education and lower income. In addition, there is recognized need for further physician education to allow early suspicion and diagnosis of occupational asthma.     

Individual and occupational risk factors for knee osteoarthritis: results of a case-control study in Germany

Introduction

A number of occupational risk factors are discussed in relation to the development and progress of knee joint diseases (for example, working in a kneeling or squatting posture, lifting and carrying heavy weights). Besides the occupational factors, a number of individual risk factors are important. The distinction between work-related and other factors is crucial in assessing the risk and in deriving preventive measures in occupational health.

Methods

In a case-control study, patients with and without symptomatic knee osteoarthritis (OA) were questioned by means of a standardised questionnaire complemented by a semi-standardised interview. Controls were matched and assigned to the cases by gender and age. Conditional logistic regression was used in analysing data.

Results

In total, 739 cases and 571 controls were included in the study. In women and men, several individual and occupational predictors for knee OA could be described: obesity (odds ratio (OR) up to 17.65 in women and up to 12.56 in men); kneeling/squatting (women, OR 2.52 (>8,934 hours/life); men, 2.16 (574 to 12,244 hours/life), 2.47 (>12,244 hours/life)); genetic predisposition (women, OR 2.17; men, OR 2.37); and sports with a risk of unapparent trauma (women, OR 2.47 (≥1,440 hours/life); men, 2.58 (≥3,232 hours/life)). In women, malalignment of the knee (OR 11.54), pain in the knee already in childhood (OR 2.08), and the daily lifting and carrying of loads (≥1,088 tons/life, OR 2.13) were related to an increased OR; sitting and smoking led to a reduced OR.

Conclusions

The results support a dose-response relationship between kneeling/squatting and symptomatic knee OA in men and, for the first time, in women. The results concerning general and occupational predictors for knee OA reflect the findings from the literature quite well. Yet occupational risks such as jumping or climbing stairs/ladders, as discussed in the literature, did not correlate with symptomatic knee OA in the present study. With regards to occupational health, prevention measures should focus on the reduction of kneeling activities and the lifting and carrying of loads as well as general risk factors, most notably the reduction of obesity. More intervention studies of the effectiveness of tools and working methods for reducing knee straining activities are needed.     

Interleukin-4 rs2243250 polymorphism is associated with asthma among Caucasians and related to atopic asthma

Published data on the association between interleukin-4 (IL-4) rs2243250 (C-589T) polymorphism and asthma susceptibility are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 17 studies with 3037 asthma patients and 3032 healthy controls were included. Overall, significantly elevated asthma risk was associated with IL-4 T allele when all studies were pooled into the meta-analysis (CT vs. CC: OR=1.187, 95% CI=1.016-1.387; dominant model: OR=1.213, 95% CI=1.046-1.405). In the subgroup analysis by ethnicity, significantly increased risk was only found for Caucasians (TT vs. CC: OR=1.591, 95% CI=1.032-2.452; dominant model: OR=1.292, 95% CI=1.028-1.624). When stratified by asthma type, statistically significantly elevated risk was only found in atopic asthma group (dominant model: OR=1.313, 95% CI=1.033-1.667). Despite some limitations, this meta-analysis suggests that T allele at position -589 of the IL-4 gene promoter region is a low-penetrant risk factor for asthma development especially for Caucasians and atopic type.     

A Systematic Review on the Development of Asthma and Allergic Diseases in Relation to International Immigration: The Leading Role of the Environment Confirmed

Background

The prevalence of asthma and allergic diseases is rising worldwide. Evidence on potential causal pathways of asthma and allergies is growing, but findings have been contradictory, particularly on the interplay between allergic diseases and understudied social determinants of health like migration status. This review aimed at providing evidence for the association between migration status and asthma and allergies, and to explore the mechanisms between migration status and the development of asthma and allergies.

Methods and Findings

Systematic review on asthma and allergies and immigration status in accordance with the guidelines set by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The pooled odds ratio (OR) of the prevalence of asthma in immigrants compared to the host population was 0.60 (95% CI 0.45–0.84), and the pooled OR for allergies was 1.01 (95% CI 0.62–1.69). The pooled OR for the prevalence of asthma in first generation versus second generation immigrants was 0.37 (95% CI 0.25–0.58). Comparisons between populations in their countries of origin and those that emigrated vary depending on their level of development; more developed countries show higher rates of asthma and allergies.

Conclusions

Our findings suggest a strong influence of the environment on the development of asthma and allergic diseases throughout the life course. The prevalence of asthma is generally higher in second generation than first generation immigrants. With length of residence in the host country the prevalence of asthma and allergic diseases increases steadily. These findings are consistent across study populations, host countries, and children as well as adults. Differences have been found to be significant when tested in a linear model, as well as when comparing between early and later age of migration, and between shorter and longer time of residence.     

Asthma during Pregnancy in a Population-Based Study - Pregnancy Complications and Adverse Perinatal Outcomes

Background

Asthma is one of the most common chronic diseases, and prevalence, severity and medication may have an effect on pregnancy. We examined maternal asthma, asthma severity and control in relation to pregnancy complications, labour characteristics and perinatal outcomes.

Methods

We retrieved data on all singleton births from July 1, 2006 to December 31, 2009, and prescribed drugs and physician-diagnosed asthma on the same women from multiple Swedish registers. The associations were estimated with logistic regression.

Results

In total, 266 045 women gave birth to 284 214 singletons during the study period. Maternal asthma was noted in 26 586 (9.4%) pregnancies. There was an association between maternal asthma and increased risks of pregnancy complications including preeclampsia or eclampsia (adjusted OR 1.15; 95% CI 1.06–1.24) and premature contractions (adj OR 1.52; 95% CI 1.29–1.80). There was also a significant association between maternal asthma and emergency caesarean section (adj OR 1.29; 95% CI 1.23–1.34), low birth weight, and small for gestational age (adj OR 1.23; 95% CI 1.13–1.33). The risk of adverse outcomes such as low birth weight increased with increasing asthma severity. For women with uncontrolled compared to those with controlled asthma the results for adverse outcomes were inconsistent displaying both increased and decreased OR for some outcomes.

Conclusion

Maternal asthma is associated with a number of serious pregnancy complications and adverse perinatal outcomes. Some complications are even more likely with increased asthma severity. With greater awareness and proper management, outcomes would most likely improve.     

Risk factors for hospitalization among adults with asthma: the influence of sociodemographic factors and asthma severity

Background

The morbidity and mortality from asthma have markedly increased since the late 1970s. The hospitalization rate, an important marker of asthma severity, remains substantial.

Methods

In adults with health care access, we prospectively studied 242 with asthma, aged 18–50 years, recruited from a random sample of allergy and pulmonary physician practices in Northern California to identify risk factors for subsequent hospitalization.

Results

Thirty-nine subjects (16%) reported hospitalization for asthma during the 18-month follow-up period. On controlling for asthma severity in multiple logistic regression analysis, non-white race (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1–8.8) and lower income (OR, 1.1 per $10,000 decrement; 95% CI, 0.9–1.3) were associated with a higher risk of asthma hospitalization. The severity-of-asthma score (OR, 3.4 per 5 points; 95%, CI 1.7–6.8) and recent asthma hospitalization (OR, 8.3; 95%, CI, 2.1–33.4) were also related to higher risk, after adjusting for demographic characteristics. Reliance on emergency department services for urgent asthma care was also associated with a greater likelihood of hospitalization (OR, 3.2; 95% CI, 1.0–9.8). In multivariate analysis not controlling for asthma severity, low income was even more strongly related to hospitalization (OR, 1.2 per $10,000 decrement; 95% CI, 1.02–1.4).

Conclusion

In adult asthmatics with access to health care, non-white race, low income, and greater asthma severity were associated with a higher risk of hospitalization. Targeted interventions applied to high-risk asthma patients may reduce asthma morbidity and mortality.     

Health outcomes of road-traffic pollution among exposed roadside workers in Rawalpindi City,Pakistan

To document ill-health effects of air pollution on the local inhabitants, we analyzed the self-reported health issues associated with the inhalation of road traffic on daily basis. For this purpose, a revised version of ALS-DLD-78S questionnaire was administered, comprising the personal information and details related to the clinical history of the surveyed population (i.e. n = 580). Five dependent (outcome) variables, including chest pain, redness of eyes, shortness of breath, eye-tearing, and skin-itching were taken into account. The results revealed that ～80% of the surveyed population were directly or indirectly exposed to road traffic, and the incidence of chest pain among exposed individuals was estimated to increase with age (odds ratio (OR) = 6.49; 95% confidence interval (CI) = 1.46–28.81), especially among cardiac patients (OR = 13.87; 95%-CI = 3.28–58.61). However, the shortness of breath was predominantly observed among those who reported to have asthmatic symptoms (OR = 32.84; 95%-CI = 15.59–69.15) and cardiovascular symptoms (OR = 13.8: 95%-CI = 3.63–52.41). In case of itching, the population along the roadside were more vulnerable to exposure (OR = 5.79; 95%-CI = 2.81–11.93). While, exposure to traffic exhaust could be attributed to ～3.13% rise in the incidences of redness of eyes among general population, the outcomes of this survey show that daily exposure to traffic pollution is an important health concern for the urban population in general, as well as for various occupational groups in particular, working in outdoor environment.     

三甲综合医院住院医师职业倦怠现状调查与影响因素分析

目的:探究三甲综合医院住院医师职业倦怠的发生现状及其影响因素,为预防三甲综合医院住院医师发生职业倦怠提供依据。方法:选择三甲综合医院各临床住院医师218名为研究对象,采用问卷调查住院医师性别、年龄、文化程度、职务、婚姻状况、职称、工作时间、编制及身体健康情况等基线资料及职业倦怠程度,采用logistics回归分析住院医师职业倦怠的影响因素。结果:218例三甲住院医师中119例人(54.59%)发生职业倦怠,其中轻度倦怠者60人(27.52%),中度倦怠者49人(22.48%),重度倦怠者10人(4.59%);身体健康状况一般、差(OR=1.547,5.342;P0.05)是住院医师发生职业倦怠的危险因素,职称为初级、中级、副高及以上(OR=0.893,0.827,0.736;P0.05)是住院医师发生职业倦怠的保护因素。结论:三甲住院医师职业倦怠发生的现状不容乐观,无编制、身体健康状况一般、差是住院医师发生职业倦怠的危险因素,职称为初级、中级、副高及以上是住院医师发生职业倦怠的保护因素。     

A review of allergic respiratory disease in laboratory animal workers.

There is increased recognition of hypersensitivity lung disease among workers with laboratory animals as an occupational disease. Symptoms of asthma in 44 of 78 workers with laboratory animal dander allergy reflected the serious consequences of this occupational ailment. Affected employee profiles induced family history of atopy; immediate (Type I) allergic reaction; symptoms of rhinitis, asthma, and cough; hypersensitivity to one or more species, most often rats, mice, and rabbits. Diagnosis depends on history and physical, radiologic, and laboratory examinations, including skin tests with relevant antigens. Control and treatment depend on environmental change (reemployment or reduction of antigen contact); mechanical devices (masks and filters); chemotherapy (bronchodilators, steroids), prophylaxis and immunotherapy (hyposensitization). Standardization of medico-legal criteria covering occupational asthma is needed.     

Sex-Based Differences in Asthma among Preschool and School-Aged Children in Korea

The purpose of this study was to explore risk factors related to asthma prevalence among preschool and school-aged children using a representative national dataset from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted from 2009–2011. We evaluated the demographic information, health status, household environment, socioeconomic status, and parents’ health status of 3,542 children aged 4–12 years. A sex-stratified multivariate logistic regression was used to obtain adjusted prevalence odds ratios (ORs) and 95% confidence intervals after accounting for primary sample units, stratification, and sample weights. The sex-specific asthma prevalence in the 4- to 12-year-old children was 7.39% in boys and 6.27% in girls. Boys and girls with comorbid atopic dermatitis were more likely to have asthma than those without atopic dermatitis (boys: OR = 2.20, p = 0.0071; girls: OR = 2.33, p = 0.0031). Boys and girls with ≥1 asthmatic parent were more likely to have asthma than those without asthmatic parents (boys: OR = 3.90, p = 0.0006; girls: OR = 3.65, p = 0.0138). As girls got older, the prevalence of asthma decreased (OR = 0.90, p = 0.0408). Girls residing in rural areas were 60% less likely to have asthma than those residing in urban areas (p = 0.0309). Boys with ≥5 family members were more likely to have asthma than those with ≤3 family members (OR = 2.45, p = 0.0323). The factors related to asthma prevalence may differ depending on sex in preschool and school-aged children. By understanding the characteristics of sex-based differences in asthma, individualized asthma management plans may be established clinically.     

Factors Associated with Fatal Occupational Accidents among Mexican Workers: A National Analysis

Objective

To identify the factors associated with fatal occupational injuries in Mexico in 2012 among workers affiliated with the Mexican Social Security Institute.

Methods

Analysis of secondary data using information from the National Occupational Risk Information System, with the consequence of the occupational injury (fatal versus non-fatal) as the response variable. The analysis included 406,222 non-fatal and 1,140 fatal injuries from 2012. The factors associated with the lethality of the injury were identified using a logistic regression model with the Firth approach.

Results

Being male (OR=5.86; CI95%: 4.22-8.14), age (OR=1.04; CI95%: 1.03-1.06), employed in the position for 1 to 10 years (versus less than 1 year) (OR=1.37; CI95%: 1.15-1.63), working as a facilities or machine operator or assembler (OR: 3.28; CI95%: 2.12- 5.07) and being a worker without qualifications (OR=1.96; CI95%: 1.18-3.24) (versus an office worker) were associated with fatality in the event of an injury. Additionally, companies classified as maximum risk (OR=1.90; CI 95%: 1.38-2.62), workplace conditions (OR=7.15; CI95%: 3.63-14.10) and factors related to the work environment (OR=9.18; CI95%:4.36-19.33) were identified as risk factors for fatality in the event of an occupational injury.

Conclusions

Fatality in the event of an occupational injury is associated with factors related to sociodemographics (age, sex and occupation), the work environment and workplace conditions. Worker protection policies should be created for groups with a higher risk of fatal occupational injuries in Mexico.     

Greater severity of new onset asthma in allergic subjects who smoke: a 10-year longitudinal study

Background

Little is known about the association between cigarette smoking and asthma severity. We assessed smoking as a determinant of disease severity and control in a cohort of clinic-referred allergic subjects who developed new onset asthma.

Methods

Allergic rhinitis subjects with no asthma (n = 371) were followed-up for 10 years and routinely examined for asthma diagnosis. In those who developed asthma (n = 152), clinical severity and levels of asthma control were determined. Among these subjects, 74 (48.7%) were current smokers, 17 (11.2%) former smokers, and 61 (40.1%) never smokers.

Results

When comparing current or past smokers to never smokers they had a higher risk of severe asthma in the univariate analysis, which became non-significant in the multivariate analysis. On the other hand, the categories of pack-years were significantly related to severe asthma in a dose response relationship in both the univariate and multivariate analysis: compared to 0 pack years, those who smoked 1-10 pack-years had an OR(95% CI) of 1.47(0.46-4.68), those who smoked 11-20 pack-years had an OR of 2.85(1.09-7.46) and those who smoked more than 20 pack-years had an OR of 5.59(1.44-21.67) to develop more severe asthma. Smokers with asthma were also more likely to have uncontrolled disease. A significant dose-response relationship was observed for pack-years and uncontrolled asthma. Compared to 0 pack years, those who smoked 1-10 pack-years had an OR of 5.51(1.73-17.54) and those who smoked more than 10 pack-years had an OR of 13.38(4.57-39.19) to have uncontrolled asthma.

Conclusions

The current findings support the hypothesis that cigarette smoking is an important predictor of asthma severity and poor asthma control.     

CXCR3 polymorphisms associated with risk of asthma

The chemokine (C-X-C motif) receptor 3 (CXCR3) gene, on chromosome Xq13, is known to have critical roles in inflammatory and immune responses. In an effort to discover polymorphisms have been implicated in asthma, we investigated the genetic polymorphisms in CXCR3 to evaluate it as a potential candidate gene for a host genetic study of asthma. Statistical analysis revealed that one SNP in intron 1, c.12+234G > A, showed significant association with the risk of asthma development (P = 0.007, OR = 0.81). By subgroup analyses stratified by gender and atopic status, the genetic effect of c.12+234G > A on asthma was more apparent among male atopic subjects (P = 0.0009, OR = 0.61). Our findings suggest that polymorphisms in CXCR3 might be one of the genetic factors for the risk of asthma development, especially in male atopic subjects. CXCR3 variation/haplotype information identified in this study will provide valuable information and insight into strategies for the control of asthma and its subgroup, atopy.     

Intercellular adhesion molecule-1 and childhood asthma

We investigated the role of intercellular adhesion molecule-1 in childhood asthma by examining associations of functional variants at codons 29 (AT), 241 (GA), and 469 (AG) in Childrens Health Study participants. Among African-Americans, 469G carriers had lower risk for asthma (ever asthma OR=0.4, 95% CI 0.2–0.9) but increased risk among 29T carriers (early onset active asthma OR=2.2, 95% CI 1.0–4.9). Protective associations with the 241A allele were observed among non-Hispanic and Hispanic whites (ever asthma OR=0.7, 95% CI 0.6–0.9; early onset active asthma OR=0.5, 95% CI 0.4–0.8), and these associations were not confounded by population stratification. To gauge the potential impact of confounding by population stratification, we performed analyses by ethnic group and in an independent family-based sample. Regional associations were stable across analyses. Haplotype associations of the four common haplotypes (29A/241G/469A, AGG, TGA, and AAG) with asthma showed that Hispanics with the AAG haplotype had lower asthma risk compared to carriers of two copies of AGA haplotype (OR=0.6, 95% CI 0.4–0.9). Among non-Hispanic whites, the AAG haplotype was associated with reduced risk for active asthma. For African-Americans, who had a low frequency of the AAG haplotype, carrying one copy of the AGG haplotype was associated with a lower risk of asthma (OR=0.3, 95% CI 0.1–0.8), as compared with two copies of the AGA haplotype. Consistent with information on variant function, the 241A and 469G variants may indicate haplotypes that are associated with reduced risk for asthma.     

Higher prevalence of obesity among children with asthma

The aim of this study is to investigate the association between childhood obesity and asthma, and whether this relationship varies by race/ethnicity. For this population-based, cross-sectional study, measured weight and height, and asthma diagnoses were extracted from electronic medical records of 681,122 patients aged 6-19 years who were enrolled in an integrated health plan 2007-2009. Weight class was assigned based on BMI-for-age. Overall, 18.4% of youth had a history of asthma and 10.9% had current asthma. Adjusted odds of current asthma for overweight, moderately obese, and extremely obese youth relative to those of normal weight were 1.22 (95% confidence interval (CI): 1.20, 1.24), 1.37 (95% CI: 1.34, 1.40), and 1.68 (95% CI: 1.64, 1.73), respectively (P trend < 0.001). Black youth are nearly twice as likely (adjusted odds ratio (OR) = 1.93, 95% CI: 1.89, 1.99), and Hispanic youth are 25% less likely (adjusted OR = 0.75, 95% CI: 0.74, 0.77), to have current asthma than to non-Hispanic white youth. However, the relationship between BMI and asthma was strongest in Hispanic and weakest in black youth. Among youth with asthma, increasing body mass was associated with more frequent ambulatory and emergency department visits, as well as increased inhaled and oral corticosteroid use. In conclusion, overweight, moderate, and extreme obesity are associated with higher odds of asthma in children and adolescents, although the association varies widely with race/ethnicity. Increasing BMI among youth with asthma is associated with higher consumption of corticosteroids and emergency department visits.