Differences In Asthma Prevalence Research Articles

Asthma and allergies in a cohort of adolescents conceived with ART

Research questionAre asthma and allergies more common in adolescents conceived with assisted reproductive technologies (ART) compared with adolescents conceived without? DesignThe Growing Up Healthy Study (GUHS) is a prospective cohort study including ART-conceived offspring born between 1991 and 2001 in Perth, Australia. Their long-term health outcomes, including asthma and allergy parameters, were compared with those of their counterparts conceived without ART from the Raine Study Generation 2 (Gen2), born in 1989–1991. At age 14, 152 GUHS and 1845 Gen2 participants completed the following assessments: the International Studies of Asthma and Allergies in Childhood (ISAAC) questionnaire, spirometry, methacholine challenge testing and skin prick testing (SPT). ResultsNo differences were detected in the prevalence of current asthma (7.7% versus 10.8%, adjusted odds ratio [aOR] 0.82 (95% CI 0.44–1.52), P = 0.530). Spirometry-measured lung volumes were larger in the ART adolescents. Bronchial hyperresponsiveness was less prevalent in the ART cohort (8.8 versus 18.6%, P = 0.006). Current allergic rhinoconjunctivitis (ARC) rates were significantly higher in the ART cohort (32.4% versus 25.2%, aOR 1.52 [95% CI 1.03–2.26], P = 0.036), with no cohort differences in atopic dermatitis. Food allergies were more prevalent in the ART cohort (20.7 versus 10.9%, aOR 1.89 [95% CI 1.17–3.06], P = 0.010) with more adolescents having a positive SPT (68.0% versus 45.4%, aOR 3.03 [95% 1.99–4.63], P < 0.001). ConclusionsThis study reports no differences in asthma prevalence, slightly altered lung function, an increase in ARC, food allergies and positive SPT in the ART-conceived adolescents. These findings are important to families and healthcare providers and may open up possibilities for targeted screening and treatment. Further studies are required to confirm these findings.

O-087 Asthma and allergies in a cohort of adolescents conceived after assisted reproductive technologies (ART)

Abstract Study question Are adolescents conceived after assisted reproductive technologies (ART) at an increased risk of asthma and allergies, compared to their counterparts conceived without ART? Summary answer No difference in asthma prevalence, better lung-function, and an increase in allergic rhinoconjunctivitis, food allergies and positive skin-prick tests are reported in the ART cohort. What is known already Over 8 million children have been born after conception with ART worldwide. Emerging evidence shows an increased risk of atopic disorders, such as asthma and allergies, in such children, potentially due to epigenetic alterations or underlying parental subfertility and perinatal risk factors. Studies to date are highly heterogeneous, including non-standardized diagnostic tools, non-representative reference populations, and lacking appropriate covariate adjustment. With the increase in atopic disorders worldwide, and the burden they bring to the life of individuals and to society, in combination with the increase in ART, it is important to further investigate the risk of atopy in such offspring. Study design, size, duration The Growing Up Healthy Study (GUHS) is a prospective study that recruited 303 offspring conceived after ART (aged 13-21), born 1991-2001 in Western Australia. Their health parameters, including asthma and allergy assessments, were compared with those of counterparts conceived without ART, from the Raine Study Generation 2 (Gen2). The 2,868 Gen2 participants are representative of the local population. At age 14 (2013-2017), 152 GUHS participants replicated atopy assessments previously completed by similarly aged Gen2 participants. Participants/materials, setting, methods Asthma and allergy assessments consisted of a parent-completed modified version of the ‘International Studies of Asthma and Allergies in Childhood’ (ISAAC) questionnaire, spirometry, methacholine challenge- and skin-prick testing (SPT). Chi2, Fisher’s Exact and Mann-Whitney U tests, performed in SPSS V25, examined cohort differences, and generalized estimating equations adjusted for (a subset of) the following covariates: sex, age, height, singleton pregnancy, gestational age, birthweight, mode of delivery, primary caregiver smoking, and being an only child. Main results and the role of chance Current asthma and asthma severity, based on the ISAAC questionnaire, appeared similar between the cohorts. Lung function (mean Forced Expiratory Volume [FEV1], Forced Vital Capacity [FVC] and FEV1/FVC ratio) was better in the ART cohort (3.10 vs. 2.96 L, p = 0.011; 3.72 vs. 3.29 L, p &amp;lt; 0.001; 85.5 vs. 91.8%, p &amp;lt; 0.001, respectively). No difference in mean Forced Expiratory Flow was reported. Bronchial hyperresponsiveness was significantly less prevalent in the ART cohort (8.8% vs.18.6% p = 0.006). Current allergic rhinoconjunctivitis (ARC) rates were significantly higher in the ART cohort (32.4% vs. 25.2%, aOR 1.52 [1.03-2.26], p = 0.036), while prevalence of current atopic dermatitis did not differ. Food allergies were twice as prevalent in the ART cohort (20.7 vs. 10.9%, aOR 1.89 [1.17-3.06], p = 0.010). Significantly more GUHS participants had a positive SPT (68.0% vs. 45.4%, aOR 3.034 [1.989-4.628], p &amp;lt; 0.001). The percentage of polysensitisation (&amp;gt; 1 allergen) did not differ between the cohorts. Sub-analyses comparing offspring conceived after in vitro fertilisation (IVF)[n = 100] and intracytoplasmic sperm injection (ICSI)[n = 40], and fresh and frozen embryo transfers (ETs n = 82, FETs n = 58) within the ART cohort, showed no significant differences, although all allergy outcomes appeared more prevalent in the ET group. Limitations, reasons for caution Despite substantial study size, numbers did not allow for adjustment for all covariates. Sub-analyses (IVF vs. ICSI and ET vs. FET), were conducted with limited power and require replication in larger cohorts. Both cohorts were largely of Caucasian decent (&amp;gt;88.0%), which reduces applicability of findings to other ethnicities. Wider implications of the findings Reassuringly, adolescents conceived after ART had better lung-function than their counterparts and no differences in asthma prevalence. The reported increase in allergies in ART conceived adolescents is of importance to families and healthcare providers, and opens possibilities for targeted screening and treatment. Further studies are required to confirm our findings. Trial registration number Not applicable

Relationship between Dietary Fiber and Allergy Prevalence in a College Population

ObjectivesTo characterize the relationship between dietary fiber intake and the prevalence of allergic diseases, seasonal allergies and asthma, in a college student population.MethodsData were collected from 2012–2021 through the College Health and Nutrition Assessment Survey, an ongoing cross-sectional study at a midsized, public New England university. Students (18–24 years; n = 4135; 67% female) completed a comprehensive, online demographic and health information survey, a 3-day food record, and an analysis of their average nutrient intake via an online program (Diet and Wellness Plus). After stratifying by sex, students’ fiber intake (g/day) were grouped into quartiles; differences in allergy and asthma prevalence across quartiles were evaluated via chi-square tests. Logistic regression was used to examine differences in allergy and asthma prevalence between low fiber intake and those with higher intakes after controlling for covariates BMI, smoking status, and alcohol consumption.ResultsOf the final sample, 37.6% and 19.2% reported a seasonal allergy and asthma, respectively, after exclusion of participants with missing data (4135 of 5093). Food records indicate only 18.2% of females and 12.2% of males are meeting recommended intakes of dietary fiber. Quartile fiber consumption was associated with seasonal allergy prevalence in males (X2 = 10.657, df = 3, P = 0.014) and females (X2 = 15.526, df = 3, P = 0.001). Females consuming the lowest quartile of fiber intake (<13.62 g/day) experience 1.39 times the odds of seasonal allergies (P < 0.001, 95% CI 1.164–1.651) when controlling for the covariates of BMI, smoking status, and alcohol use. No significant differences in asthma prevalence were identified between fiber intake quartiles.ConclusionsConsistent with previously identified associations, our findings suggest fiber intake is related to seasonal allergies but not asthma, with a stronger relationship among females. This study further emphasizes the need to investigate potential dietary risk factors for allergic diseases and to inform institutions on key dietary priorities for college student health.Funding SourcesNew Hampshire Agriculture Experiment Station and USDA National Institute of Food and Agriculture Hatch Project 1,010,738.

Genome-Wide Interaction Study of Late-Onset Asthma With Seven Environmental Factors Using a Structured Linear Mixed Model in Europeans.

Asthma is among the most common chronic diseases worldwide, creating a substantial healthcare burden. In late-onset asthma, there are wide global differences in asthma prevalence and low genetic heritability. It has been suggested as evidence for genetic susceptibility to asthma triggered by exposure to multiple environmental factors. Very few genome-wide interaction studies have identified gene-environment (G×E) interaction loci for asthma in adults. We evaluated genetic loci for late-onset asthma showing G×E interactions with multiple environmental factors, including alcohol intake, body mass index, insomnia, physical activity, mental status, sedentary behavior, and socioeconomic status. In gene-by-single environment interactions, we found no genome-wide significant single-nucleotide polymorphisms. However, in the gene-by-multi-environment interaction study, we identified three novel and genome-wide significant single-nucleotide polymorphisms: rs117996675, rs345749, and rs17704680. Bayes factor analysis suggested that for rs117996675 and rs17704680, body mass index is the most relevant environmental factor; for rs345749, insomnia and alcohol intake frequency are the most relevant factors in the G×E interactions of late-onset asthma. Functional annotations implicate the role of these three novel loci in regulating the immune system. In addition, the annotation for rs117996675 supports the body mass index as the most relevant environmental factor, as evidenced by the Bayes factor value. Our findings help to understand the role of the immune system in asthma and the role of environmental factors in late-onset asthma through G×E interactions. Ultimately, the enhanced understanding of asthma would contribute to better precision treatment depending on personal genetic and environmental information.

Asthma, allergy and vitamin E: Current and future perspectives

Asthma and allergic disease result from interactions of environmental exposures and genetics. Vitamin E is one environmental factor that can modify development of allergy early in life and modify responses to allergen after allergen sensitization. Seemingly varied outcomes from vitamin E are consistent with the differential functions of the isoforms of vitamin E. Mechanistic studies demonstrate that the vitamin E isoforms α-tocopherol and γ-tocopherol have opposite functions in regulation of allergic inflammation and development of allergic disease, with α-tocopherol having anti-inflammatory functions and γ-tocopherol having pro-inflammatory functions in allergy and asthma. Moreover, global differences in prevalence of asthma by country may be a result, at least in part, of differences in consumption of these two isoforms of tocopherols. It is critical in clinical and animal studies that measurements of the isoforms of tocopherols be determined in vehicles for the treatments, and in the plasma and/or tissues before and after intervention. As allergic inflammation is modifiable by tocopherol isoforms, differential regulation by tocopherol isoforms provide a foundation for development of interventions to improve lung function in disease and raise the possibility of early life dietary interventions to limit the development of lung disease.

Between and Within Sexual Identity-Group Differences in Asthma Prevalence in the United States.

Although prior studies have established the association of asthma with smoking and obesity, literature on difference-in-differences analyses involving sexual identity is sparse. Therefore, this study aimed to examine the between and within sexual identity-group differences in asthma prevalence among individuals who smoke and are obese. We aggregated the 2017-2019 National Survey on Drug Use and Health data on adults (N = 128,319) to perform weighted multivariable logistic regression analysis and marginal estimates and marginsplot to determine asthma prevalence by sexual identity and the status of smoking and obesity. About 66% of the study population reported having asthma. Among the individuals with asthma, 42% were obese, 10% were daily cigarette smokers, and 6% identified as bisexual persons. Lesbian/gay daily smokers (86%) or former smokers (75%) had a higher probability of having asthma than bisexual (daily smokers = 78% vs former smokers = 72%) and heterosexual (daily smokers = 68% vs former smokers = 65%) persons. Within each sexual identity subgroup, daily smokers (68-86%) had the highest probability of asthma. Obese bisexual (73%) or lesbian/gay (72%) persons had higher probabilities of having asthma than heterosexual persons (69%). Obese (73%) or overweight (72%) bisexual (compared to normal weight = 70% or underweight = 51%) and obese (69%) or overweight (65%) heterosexual (compared to normal weight = 62% or underweight = 57%) persons had the highest probabilities of having asthma within their groups, whereas overweight persons (overweight = 81% vs underweight = 79%, normal weight = 78%, and obese = 72%) had the highest probabilities within lesbian/gay persons. Smoking and obesity show heightened odds for asthma, with significant odds for sexual minorities in asthma diagnosis relative to heterosexuals. These findings provide formative information for future longitudinal and experimental studies to explore these mechanisms of asthma risks among sexual and gender minorities.

Higher prevalence but later age at onset of asthma in cross-country skiers compared with general population.

Cross-country skiing causes strain in the airways because skiers train and compete in cold air. The aim of this survey was to investigate the prevalence and age at onset of asthma, asthma control, and use of asthma medication in Finnish competitive cross-country skiers. All cross-country skiers who were enrolled in the largest national competitions in winter 2019 (n=1282) were invited to the study via the Finnish Ski Association. A control group (n=1733) was matched for the responding skiers by age, gender, and region. The response rate was 27.4% (n=351) for skiers and 19.5% (n=338) for the controls. The prevalence of asthma was 25.9% in skiers and 9.2% in the controls (p<0.001). Median (IQR) age at first asthma-related symptoms was higher in skiers than in the controls (13.0 (8.25-16.0) vs. 8.0 (2.25-11.75) years, p<0.001), and the difference in asthma prevalence was evident only after the start of skiing career. Median (IQR) Asthma Control Test (ACT) score in skiers and controls with asthma was 22.0 (21-24) vs. 22.0 (19-24) (p=0.611), and 89.0% of skiers and 77.4% of controls had well-controlled asthma (ACT score ≥20). In skiers with asthma, 82.4% used regular inhaled corticosteroids (ICS), and 80.2% used bronchodilators. A fixed combination of ICS +long-acting β2-agonist was regularly used by 47.3% of the skiers and 22.6% of the controls with asthma (p=0.016). In conclusion, asthma prevalence is about 2.5 times higher, and age at onset of asthma is later in skiers compared with the controls. Asthma in cross-country skiers is mostly well controlled and on regular maintenance treatment.

Is ethnicity a 'treatable trait' in asthma?

Is ethnicity a 'treatable trait' in asthma?

Prevalence of Comorbid Asthma and Related Outcomes in COVID-19: A Systematic Review and Meta-Analysis

BackgroundThe impact of asthma on coronavirus disease 2019 (COVID-19) remains largely unknown.ObjectiveTo investigate the asthma prevalence among patients with COVID-19 and compare outcomes between patients with and without asthma.MethodsIn this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, bioRxiv, and medRxiv for studies reporting asthma prevalence in general patients with COVID-19 or comparing outcomes between patients with and without asthma, and excluded duplicate publications, reviews, editorials, comments, single case reports, or small case series (<10 cases). We determined the pooled estimates of effect using random-effect model.ResultsOn the basis of 131 studies (410,382 patients), we found great variability in the prevalence of comorbid asthma among patients with COVID-19 in different countries or regions ranging from 1.1% to 16.9%. No significant difference in asthma prevalence was found between hospitalized and nonhospitalized (risk ratio [RR], 1.15; 95% CI, 0.92-1.43), severe and nonsevere (RR, 1.21; 95% CI, 0.92-1.57), intensive care unit and non–intensive care unit (RR, 1.19; 95% CI, 0.92-1.54), dead and survived (RR, 0.90; 95% CI, 0.73-1.11), intubated/mechanically ventilated and nonintubated/mechanically ventilated (RR, 0.91; 95% CI, 0.71-1.17) patients with COVID-19. Patients with asthma have a lower risk of death compared with patients without asthma (RR, 0.65; 95% CI, 0.43-0.98). Asthma is not associated with a higher risk of intubation or mechanical ventilation (RR, 1.03; 95% CI, 0.72-1.46).ConclusionsThere is great variability in asthma prevalence among patients with COVID-19 in different countries or regions. Asthma is not associated with higher COVID-19 severity or worse prognosis, and patients with asthma are found to have a lower risk of death compared with patients without asthma.

Dust Mite Allergen Components in Children from Costa Rica, Ghana, and Ecuador: More Evidence that Der p 23 is a Major Allergen

Dust mites (DM) are a major source of indoor allergens and IgE to DM are strongly associated with allergic asthma. Der p 23 is a recently described major DM allergen but investigations to date have been limited to small cohorts and/or microchip assays. Using ImmunoCAP, we assessed specific-IgE (sIgE) to DM components (Der p 1, 2, 10 and 23) in sera of asthmatic and non-asthmatic children from Costa Rica (CR), Ghana and Ecuador who previously tested positive for sIgE to Dermatophagoides pteronyssinus. IgE to Der p 1, 2, 10 and 23 were common in asthmatics from CR (73%, 76%, 21% and 70%), Ghana (55%, 53%, 26% and 39%) and Ecuador (43%, 48%, 14%, and 36%). Correlations between sIgE to Der p 23 and Der p 1/2 were moderate-strong and using a cut-off of 0.1 IU/mL poly-sensitization to each of Der p 1, 2 and 23 was common (CR 57%, Ghana 65%, and Ecuador 48%) in all three cohorts. Among children in these countries who lived in rural areas with pre-hygiene conditions, sIgE titers to DM components were lower. Der p 23 represents a peritrophin-like-protein of DM that is present in mites at lower levels than Der p1/2, but is nonetheless a major target of IgE. The high frequency of poly-sensitization to these three proteins provides further evidence that DM are potent agents of IgE sensitization. Differences in IgE titers to DM components between pre-hygiene and post-hygiene environments parallel differences in asthma prevalence and provide additional evidence for the hygiene hypothesis.

Urbanisation and asthma in low-income and middle-income countries: a systematic review of the urban–rural differences in asthma prevalence

BackgroundUrbanisation has been associated with temporal and geographical differences in asthma prevalence in low-income and middle-income countries (LMICs). However, little is known of the mechanisms by which urbanisation and asthma...

Asthma as an outcome: Exploring multiple definitions of asthma across birth cohorts in the Environmental influences on Child Health Outcomes Children's Respiratory and Environmental Workgroup

Asthma definitions vary widely across research studies and feature a trade-off between inclusivity and precision. Harmonizing definitions across multiple asthma birth cohort studies highlights these challenges.

Sex Differences in IL-33-Induced STAT6-Dependent Type 2 Airway Inflammation.

Sex differences in asthma prevalence are well-documented but poorly understood. Murine models have contributed to our understanding of mechanisms that could regulate this sex disparity, though the majority of these studies have examined responses present after Th2 adaptive immunity is established. We have now investigated how sex influences acute activation of innate cell populations in the lung upon initial exposure to the model antigen, ovalbumin (OVA), in the presence of IL-33 (OVA+IL-33), to prime the lungs for type 2 immunity. We also examined how inflammatory responses induced by OVA+IL-33 were altered in mice lacking the STAT6 transcription factor, which is activated by IL-13, an effector cytokine of IL-33. Our data demonstrate that type 2 inflammation induced by OVA+IL-33 was more severe in female mice compared to males. Females exhibited greater cytokine and chemokine production, eosinophil influx and activation, macrophage polarization to the alternatively activated phenotype, and expansion of group 2 innate lymphoid cells (ILC2s). While increases in ILC2s and eosinophils were largely independent of STAT6 in both males and females, many other responses were STAT6-dependent only in female mice. Our findings indicate that a subset of type 2 inflammatory responses induced by OVA+IL-33 require STAT6 in both males and females and that enhanced type 2 inflammation in females, compared to males, is associated with greater IL-13 protein production. Our findings suggest blunted IL-13 production in males may protect against type 2 inflammation initiated by OVA+IL-33 delivery to the lung.

A randomized pilot trial of a school-based psychoeducational intervention for children with asthma.

Asthma is a common childhood illness with high morbidity and mortality among minority and socio-economically disadvantaged children. Disparities are not fully accounted for by differences in asthma prevalence, highlighting a need for interventions targeting factors associated with poorer asthma control. One such factor is psychological stress. Here, we examine the feasibility and acceptability of "I Can Cope (ICC)," a school-based stress management and coping intervention for children with asthma. A parallel randomized pilot trial was conducted. One hundred and four low-income children (mean age 10years; 54% male; 70% African American) with persistent asthma were recruited from 12 urban schools and randomized to the following: (a) ICC or one of two control conditions: (b) "Open Airways for Schools (OAS)"-an asthma education intervention or (c) no treatment. Seventy one percentage of eligible children participated in the study, with a dropout rate of 12%. ICC was rated as highly acceptable by participating children and parents. Preliminary efficacy data suggest that when compared with no treatment, ICC resulted in decreased symptoms of depression, perceived stress and child-reported symptoms of asthma, and improvements in sleep quality and child-reported asthma control. There were no intervention-related changes in objective measures of asthma morbidity. The magnitude of intervention effects on psychological function did not differ between the ICC and OAS groups. Results support the feasibility and acceptability of utilizing school-based interventions to access hard to reach children with asthma. Preliminary findings offer support for future, large-scale efficacy studies of school-based interventions designed to target multiple factors that contribute to asthma disparities.

Sex Bias in Asthma Prevalence and Pathogenesis.

Sex-related differences in asthma prevalence are well established and change through the reproductive phases of life. As children, boys have increased prevalence of asthma compared to girls. However, as adults, women have increased prevalence of asthma compared to men. Many factors, including genetics, environment, immunological responses, and sex hormones, affect the sex disparity associated with the development and control of asthma and other allergic diseases. Fluctuations of hormones during puberty, menstruation, pregnancy, and menopause, alter asthma symptoms and severity. In this article, we review clinical and epidemiological studies that examined the sex disparity in asthma and other allergic diseases as well as the role of sex hormones on asthma pathogenesis.

Integrating farm and air pollution studies in search for immunoregulatory mechanisms operating in protective and high-risk environments.

Studies conducted in farm environments suggest that diverse microbial exposure promotes children's lung health. The underlying mechanisms are unclear, and the development of asthma-preventive strategies has been delayed. More comprehensive investigation of the environment-induced immunoregulation is required for better understanding of asthma pathogenesis and prevention. Exposure to air pollution, including particulate matter (PM), is a risk factor for asthma, thus providing an excellent counterpoint for the farm-effect research. Lack of comparable data, however, complicates interpretation of the existing information. We aimed to explore the immunoregulatory effects of cattle farm dust (protective, Finland) and urban air PM (high-risk, China) for the first time using identical research methods. We stimulated PBMCs of 4-year-old children (N=18) with farm dust and size-segregated PM and assessed the expression of immune receptors CD80 and ILT4 on dendritic cells and monocytes as well as cytokine production of PBMCs. Environmental samples were analysed for their composition. Farm dust increased the percentage of cells expressing CD80 and the cytokine production of children's immune cells, whereas PM inhibited the expression of important receptors and the production of soluble mediators. Although PM samples induced parallel immune reactions, the size-fraction determined the strength of the effects. Our study demonstrates the significance of using the same research framework when disentangling shared and distinctive immune pathways operating in different environments. Observed stimulatory effects of farm dust and inhibitory effects of PM could shape responses towards respiratory pathogens and allergens, and partly explain differences in asthma prevalence between studied environments.

Relationship Between Gender and the Effectiveness of Montelukast: An Italian/Danish Register-Based Retrospective Cohort Study.

Rationale: Gender-related differences in asthma prevalence, pathophysiology and clinical features induced by sex steroids have been investigated, however, how gender influences response to asthma treatments in routine clinical practice have not yet been elucidated fully. This aspect is crucial for montelukast considering the jeopardization of asthmatic patients that benefit from this treatment and the existence of evidence of gender differences in leukotriene levels. Therefore, to fulfill this medical need, we investigated the role of gender on a set of montelukast' effectiveness surrogates in adults and pediatric patients with asthma.Methods: The study settings were Napoli 2 Local Health Unit (southern Italy) and the entire Danish territory. The study population was composed of adult and pediatric patients with asthma. Cumulative incidence curves, unadjusted and adjusted Cox regression were used as statistical models to compare aforementioned outcomes between genders.Results: Adult Italian male users of montelukast had a statistically lower persistence in montelukast treatment compared to female users. In the adjusted analyses, they had a higher hazard of montelukast' withdrawal (Hazard Ratio [HR] 1.07; 95% Confidence Interval [CI] 1.01–1.14), add-on/switch to a long-term treatment for asthma following montelukast withdrawal (HR 1.72; 95%CI 1.39–2.12), and rescue therapy with short-acting β2 agonist (HR 1.24; 95%CI 1.04–1.47). In the adult Danish cohort, we also found that male users had higher a hazard of rescue therapy with oral corticosteroids (HR 1.10; 95%CI 1.04–1.16). In the pediatric cohorts, no statistically significant differences were observed between genders for aforementioned outcomes.Conclusions: In adults, male gender was associated with increased hazards of montelukast discontinuation, add-on/switch to a long-term treatment for asthma following montelukast withdrawal, and rescue therapy with oral corticosteroids or short-acting β2 agonist when compared to the female gender. As expected, these associations were reversed or absent in pediatric patients.

An international comparison of risk factors between two regions with distinct differences in asthma prevalence

Background and purposeInvestigation of the geographic variation in asthma prevalence can improve our understanding of asthma etiology and management. The purpose of our investigation was to compare the prevalence of asthma and wheeze among adolescents living in two distinct international regions and to investigate reasons for observed differences. MethodsA cross-sectional survey of 13–14 year olds was completed in Saskatoon, Canada (n=1200) and Skopje, Republic of Macedonia (n=3026), as part of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase 3 study. Surveys were self-completed by students following the ISAAC protocol. Multiple logistic regression models were used to investigate associations with reports of asthma and current wheeze. A mediation analysis was then completed. ResultsAsthma prevalence was much higher in Saskatoon than Skopje (21.3% vs. 1.7%) as was the prevalence of current wheeze (28.2% vs. 8.8%). Higher paracetamol (acetaminophen) use was a consistent risk factor for asthma and wheeze in both locations and showed dose-response relationships. In both countries, paracetamol use and physical activity mediated some of the association for both asthma and wheeze. In Saskatoon, among those with current wheeze, 42.6% reported ever having a diagnosis of asthma compared to 10.2% among Skopje adolescents. ConclusionsThe results suggest that the variation in risk factors between the two locations may explain some of the differences in the prevalence of asthma and wheeze between these two study sites. However, diagnostic labeling patterns should not be ruled out as another potential explanatory factor.

Asthma prevalence and school-related hazardous air pollutants in the US-México border area

BackgroundAsthma is the most common chronic disease in children and has been linked to high levels of ambient air pollution and certain hazardous air pollutants (HAPs). Outdoor pollutants such as benzene, released by car emissions, and organic chemicals found in diesel exhaust, as well as particles and irritant gases, including nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3), contribute to an increased prevalence of respiratory diseases such as asthma. ObjectivesThe objectives of this study were to: 1) conduct a screening survey to identify high risk for asthma among school-age children in Hidalgo County, and, 2) study the potential health impact of school-related exposure to HAPs pertaining to asthma risk. MethodsWe carried out a quantitative cross-sectional study combining a school-based asthma screening survey across 198 schools in Hidalgo County, Texas, with information on school neighborhood environments, including census tract-level information on hazardous air pollutants (HAPs) and socioeconomic status (SES) in the respective school neighborhoods. HAPs levels were assessed based on the EPA 2011 National-Scale Air Toxics Assessment (NATA) while SES information was assessed using data from the 2010–2014 American Community Survey. Results2930 students completed the asthma screening survey and results showed an overall asthma prevalence of 9.4%, slightly higher than the national and state prevalence. Participants in the 14–18 years old age group showed a much higher asthma prevalence of 16.7%. When assessing school-neighborhood characteristics, our results revealed no significant differences in asthma prevalence across census tracts with different SES levels. For HAPs, in the single-pollutant model, chlorine levels showed a significant linear trend for prevalence of asthma (p=0.03) while hydrochloric acid had a marginally significant linear trend (p=0.08). The association with chlorine remained significant in the multi-pollutant model. ConclusionsAsthma prevalence among school-age children in Hidalgo County, Texas, is 9.4%, which is slightly higher than the state rate, especially among young adults, ages 14–18 years who had an asthma rate of 16.7%. Results support an association between exposures to school-neighborhood HAPs and risk for pediatric asthma, especially as related to chlorine. No significant effects of school-level SES on asthma risk were observed.

Asthma prevalence disparities and differences in sociodemographic associations with asthma, between Native Hawaiian/Other Pacific Islander, Asian, and White adults in Hawaii – Behavioral Risk Factor Surveillance System (BRFSS), 2001–2010

ABSTRACTObjectives: Despite high asthma prevalence, relatively little is known about the epidemiology of asthma in Hawaii or among Native Hawaiian/Other Pacific Islanders (NHOPI). We sought to better characterize racial/ethnic differences in asthma prevalence and in sociodemographic factors associated with asthma among Hawaii adults.Design: We conducted multivariable logistic regression using 2001–2010 Behavioral Risk Factor Surveillance System data from Hawaii, and computed adjusted prevalence and ratios.Results: Asthma prevalence markedly varied between self-identified census categories of race in Hawaii, with NHOPI having the highest estimates of both lifetime (20.9%, 95% confidence interval [CI]: 19.5%–22.4%) and current (12.2%, CI: 11.2%–13.3%) asthma. Highest asthma prevalence among NHOPI persisted after controlling for potential confounders and within most sociodemographic categories. Among females Asians reported the lowest asthma prevalence, whereas among males point estimates of asthma prevalence were often lowest for Whites. Females often had greater asthma prevalence than males of the same race, but the degree to which gender modified asthma prevalence differed by both race and sociodemographic strata. Gender disparities in asthma prevalence were greatest and most frequent among Whites, and for current asthma among all races. Sociodemographic factors potentially predictive of adult asthma prevalence in Hawaii varied by race and gender.Conclusion: Asthma disproportionately affects or is recognized more often among women and NHOPI adults in Hawaii, and occurs less or is under-reported among Asian women. The sociodemographic characteristics included in this study’s model did not explain asthma disparities between races and/or gender. This investigation provides a baseline with which to plan additionally needed prevention programs, epidemiological investigations, and surveillance for asthma in Hawaii.