Increase In Prevalence Of Asthma Research Articles

Associations between maternal fish intake and polyunsaturated fatty acid status with childhood asthma in a high fish-eating population.

Studies investigating associations between prenatal polyunsaturated fatty acid status (PUFAs), in particular the anti-inflammatory n-3 PUFAs, and the development of childhood asthma have yielded conflicting results. To determine the associations between maternal fish intake (a rich source of the n-3 PUFAs), maternal or cord PUFAs with the prevalence of childhood asthma in a high fish-eating population. We examined these associations between fish intake and PUFA concentrations with childhood asthma prevalence in the Seychelles Child Development Study Nutrition Cohort 2, a large observational study in a high fish-eating population. Maternal fish intake during pregnancy and child's fish intake at 7 years were assessed by questionnaire, with frequency reported as meals/week. Serum concentrations of PUFAs were quantified in maternal blood collected at 28 weeks' gestation (n = 1448) and in cord blood (n = 1088). Asthma in children at 7 years was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire (n = 1098). A total of 97 children (10.5%) were reported to have asthma. In regression analysis, the odds of childhood asthma were not associated with maternal fish intake or maternal PUFA status. Cord DHA concentrations were associated with increased asthma prevalence when the highest quartile (≥0.123 mg/mL) was compared with the lowest (<0.061 mg/mL). The results from this current study add to the growing body of evidence that fish consumption during pregnancy is not associated with asthma development in offspring. The associations between cord blood DHA and asthma prevalence are unexpected and warrant further investigation.

Overall and subgroup prevalence of self-reported asthma in US adults: a nationally representative cross-sectional study

Background The purpose of this study is to determine the variations in the prevalence of self-reported asthma among the adult population in the United States of America (USA), analyzing demographic characteristics, physical indicators, living habits, and sarcopenia. Methods 10,566 participants from the 2009 to 2018 National Health and Nutrition Examination Survey (NHANES) of the USA who were 20 years of age or older and not pregnant were included in the study. Results The prevalence of patients with asthma varies by age, gender, and race. The weighted prevalence is 15.5%, estimated to represent 19.36 million people in the USA (95% CI, 14.5% to 16.6%). The prevalence of self-reported asthma decreases with age, with the highest prevalence among young adults aged 20–25 for both males and females. Females were also more susceptible to asthma compared to males. The increase in asthma prevalence attributed to smoking was most pronounced among African American and Caucasian participants (p < 0.05), while its effect on Mexican American and Asian participants was relatively minor. Notably, the prevalence of asthma was significantly higher in African American and Caucasian participants with sarcopenia compared to those without sarcopenia. Conclusions The prevalence of asthma is associated to varying degrees with factors such as age, gender, smoking, and the presence of sarcopenia. The elevated prevalence of asthma among young people and females warrants attention. Intensifying efforts toward smoking cessation and the scientific management of sarcopenia could be instrumental in reducing the incidence of asthma.

The Planetary Health Diet and Its Association with Asthma and Airway Inflammation in School-Aged Children.

Poor dietary choices have been rising concurrently with an increase in asthma prevalence, especially in children. Dietary indexes that simultaneously measure the healthiness and sustainability of dietary patterns have emerged to address the dual concerns of human and planetary health. Accordingly, we aimed to evaluate adherence to a sustainable dietary pattern and its impact on airway inflammation and asthma. In this study, 660 school-aged children (49.1% females, 7-12 years) were considered. A cross-sectional analysis was performed to assess the association between diet and asthma and airway inflammation according to overweight/obesity. Diet was evaluated through the Planetary Health Diet Index (PHDI). Higher scores represent a healthier and more sustainable diet. Three definitions of asthma were considered based on a self-reported medical diagnosis, symptoms, asthma medication, measured lung function, and airway reversibility. Airway inflammation was assessed by exhaled fractional nitric oxide (eNO). We considered two categories of body mass index: non-overweight/non-obese and overweight/obese. The associations between diet with asthma and airway inflammation were estimated using adjusted binary logistic regressions. The odds of having airway inflammation decreased with the increase in PHDI score. Moreover, children in the non-overweight/non-obesity group in the fourth quartile of the PHDI had lower odds of having airway inflammation compared to children in the first quartile. Our study indicates that a healthier and sustainable diet is associated with lower levels of eNO, but only among children without overweight/obesity.

Associations of sugary beverage consumption with chronic obstructive pulmonary disease, asthma, and asthma–chronic obstructive pulmonary disease overlap syndrome: a prospective cohort study

BackgroundThe associations between specific types of sugary beverages and major chronic respiratory diseases remain relatively unexplored. ObjectivesThis study aimed to investigate the associations of sugar-sweetened beverages (SSBs), artificially sweetened beverages (ASBs), and natural juices (NJs) with chronic obstructive pulmonary disease (COPD), asthma, and asthma–chronic obstructive pulmonary disease overlap syndrome (ACOS). MethodsThis prospective cohort study included 210,339 participants from the UK Biobank. Sugary beverage intake was measured in units (glasses/cans/cartons/250 mL) through 24-h dietary questionnaires. Logistic regression and Cox proportional hazards models were used to analyze the prevalence and incidence, respectively. Quantile G-computation was used to estimate the joint associations and relative contributions of the 3 types of sugary beverages. ResultsOver a median follow-up of 11.6 y, 3491 participants developed COPD, 4645 asthma, and 523 ACOS. In prevalence analysis, certain categories of SSB and NJ consumption were associated with increased asthma prevalence, while high ASB consumption (>2 units/d) was linked to higher risks of all 3 outcomes. In incidence analysis, high SSB consumption (>2 units/d) was associated with incident COPD (hazard ratio [HR]: 1.53; 95% confidence interval [CI]: 1.19, 1.98) and asthma (HR: 1.22; 95% CI: 0.98, 1.52). Dose‒response relationships were observed for ASB consumption with all 3 outcomes (continuous HR: 1.98; 95% CI: 1.36, 2.87, for COPD; continuous HR: 1.65; 95% CI: 1.24, 2.20, for asthma; and continuous HR: 2.84; 95% CI: 1.20, 6.72, for ACOS). Moderate NJ consumption (>0–1 unit/d) was inversely associated with COPD (HR: 0.89; 95% CI: 0.82, 0.97), particularly grapefruit and orange juice. Joint exposure to these beverages (per unit increase) was associated with COPD (HR: 1.15; 95% CI: 1.02, 1.29) and asthma (HR: 1.16; 95% CI: 1.06, 1.27), with ASBs having greater positive weights than SSBs. ConclusionsConsumption of SSBs and ASBs was associated with increased risks of COPD, asthma, and potentially ACOS, whereas moderate NJ consumption was associated with reduced risk of COPD, depending on the juice type.

Component-specific clusters for diagnosis and prediction of allergic airway diseases.

Previous studies which applied machine learning on multiplex component-resolved diagnostics arrays identified clusters of allergen components which are biologically plausible and reflect the sources of allergenic proteins and their structural homogeneity. Sensitization to different clusters is associated with different clinical outcomes. To investigate whether within different allergen component sensitization clusters, the internal within-cluster sensitization structure, including the number of c-sIgE responses and their distinct patterns, alters the risk of clinical expression of symptoms. In a previous analysis in a population-based birth cohort, by clustering component-specific (c-s)IgEs, we derived allergen component clusters from infancy to adolescence. In the current analysis, we defined each subject's within-cluster sensitization structure which captured the total number of c-sIgE responses in each cluster and intra-cluster sensitization patterns. Associations between within-cluster sensitization patterns and clinical outcomes (asthma and rhinitis) in early-school age and adolescence were examined using logistic regression and binomial generalized additive models. Intra-cluster sensitization patterns revealed specific associations with asthma and rhinitis (both contemporaneously and longitudinally) that were previously unseen using binary sensitization to clusters. A more detailed description of the subjects' within-cluster c-sIgE responses in terms of the number of positive c-sIgEs and unique sensitization patterns added new information relevant to allergic diseases, both for diagnostic and prognostic purposes. For example, the increase in the number of within-cluster positive c-sIgEs at age 5 years was correlated with the increase in prevalence of asthma at ages 5 and 16 years, with the correlations being stronger in the prediction context (e.g. for the largest 'Broad' component cluster, contemporaneous: r = .28, p = .012; r = .22, p = .043; longitudinal: r = .36, p = .004; r = .27, p = .04). Among sensitized individuals, a more detailed description of within-cluster c-sIgE responses in terms of the number of positive c-sIgE responses and distinct sensitization patterns, adds potentially important information relevant to allergic diseases.

Spatial variance and estimation of nitrogen dioxide levels as a contributing factor to asthma epidemiology in Rawalpindi, Pakistan.

Asthma prevalence and morbidity are increasing rapidly worldwide, especially in developing countries. Previous studies have shown nitrogen dioxide as an important contributor to asthma prevalence along with extreme temperatures, relative humidity, and land use change. The present study aimed to assess the asthma epidemiology and association of nitrogen dioxide, temperature, and land use as a contributing factor for increasing asthma prevalence in Rawalpindi, Pakistan. Secondary data related to the frequency of asthmatics hospital visits were analyzed to figure out the hotspots of asthma by using Getis ord Gi* statistics in ArcGIS 10.2. Moreover, intraurban variation of nitrogen dioxide concentration was analyzed by passive sampling method and its association with the rate of asthmatics hospital visits in Rawalpindi, Pakistan was also researched. Results revealed the random distribution of disease with significant hotspots along with spatial variability of nitrogen dioxide in urban and rural locations. Indoor and outdoor levels of nitrogen dioxide exceed the national and world health organization standards on asthma high risk areas especially in winter season. Congested housing with poor ventilation, unplanned urbanization, cold temperature, and unclean fuel use are revealed as strong determinants of asthma prevalence in Rawalpindi, Pakistan. Extensive monitoring and interventions are needed for the reduction of both indoor and outdoor nitrogen dioxide levels to overcome the increasing rate of asthma prevalence.

The effects of the DASH dietary pattern on clinical outcomes and quality of life in adults with uncontrolled asthma: Design and methods of the ALOHA Trial

BackgroundPoor diet quality is an important risk factor for increased asthma prevalence and poor asthma control. To address the question of whether adults with asthma can benefit from following a healthy diet, this trial will test the efficacy and mechanisms of action of a behavioral intervention promoting the Dietary Approaches to Stop Hypertension (DASH) dietary pattern with sodium reduction among patients with uncontrolled asthma. MethodsIn this 2-arm randomized clinical trial, 320 racially/ethnically and socioeconomically diverse adults with uncontrolled asthma on standard controller therapy will be randomized to either a control or an intervention group and assessed at baseline, 3, 6 and 12 months. Control and intervention participants will receive education on lung health, asthma, and other general health topics; additionally, the intervention group will receive DASH behavioral counseling over 12 months. The primary hypothesis is that the DASH behavioral intervention, compared with the education-only control, will lead to significantly more participants with minimum clinically important improvement (responders) in asthma-specific quality of life at 12 months. Secondary hypotheses will test the intervention effects on other asthma (e.g., asthma control, lung function) and non-asthma outcomes (e.g., quality of life). Additionally, therapeutic (e.g., short chain fatty acids, cytokines) and nutritional biomarkers (e.g., dietary inflammatory index, carotenoids) will be assessed to understand the mechanisms of the intervention effect. ConclusionThis trial can substantially advance asthma care by providing rigorous evidence on the benefits of a behavioral dietary intervention and mechanistic insights into the role of diet quality in asthma.clinicaltrials.gov #: NCT05251402

Trend of asthma prevalence and risk factors in the 20s age band in South Korea.

The prevalence of asthma has increased in many countries. However, whether asthma prevalence may only be true in a specific age band is not well known. Thus, we analyzed the increase in asthma prevalence according to age band and analyzed the related factors. We analyzed the trend of asthma prevalence according to 10-year age band intervals by using 2007 to 2018 data from the Korean National Health and Nutrition Survey. We determined the presence of subject-reported, physician-diagnosed asthma in 89,179 subjects. Multiple logistic regression analyses with a complex sample design were conducted to identify the risk factors for asthma. Among all age ranges, only the 20s age band showed an increase in the trend of asthma prevalence from 0.7% in 2007 to 5.1% in 2018 (P<0.001 for joinpoint regression). Among the 7,658 subjects in the 20s age band, 237 (3.1%) subjects were asthma. In asthma group, 54.9% were male, 43.9% were ever-smokers, 44.6% had allergic rhinitis, 25.3% had atopic dermatitis, and 29.1% were obese. Multiple logistic regression analysis showed that asthma was related to allergic rhinitis [odds ratio (OR), 2.78; 95% confidence interval (CI): 2.03-3.81] and atopic dermatitis (OR, 4.13; 95% CI: 2.85-5.98), but not to male sex, ever-smoking, obesity, or socioeconomics status. From 2007 to 2018, the prevalence of asthma significantly increased in the 20s age band in South Korea. This may be related to the increase in the cases of allergic rhinitis and atopic dermatitis.

Association of weight-adjusted-waist index with asthma prevalence and the age of first asthma onset in United States adults.

The objective of this study was to assess whether the weight-adjusted-waist index(WWI) is associated with the prevalence of asthma and age when first asthma onset appears in US adults. For analysis we selected participants from the National Health and Nutrition Examination Survey(NHANES)database between 2001 and 2018.A dose-response curve was calculated using logistic regression,subgroup analysis,and a dose-response curve. The study included 44480 people over the age of 20,including 6061 reported with asthma, and the increase in asthma prevalence was 15% associated with each unit increase in the WWI, after adjusting for all confounders(odds ratio(OR)=1.15,95% CI:1.11,1.20). The sensitivity analysis was performed by trichotomizing the WWI, and compared to the lowest tertile, the highest tertile WWI group displayed a 29% increase in asthma prevalence(OR=1.29,95% CI:1.19,1.40). A nonlinear correlation was found between the WWI index and the risk of asthma onset, with a threshold saturation effect indicating an inflection point of 10.53 (log-likelihood ratio test, P<0.05), as well as a positive linear correlation with age at first asthma onset. A higher WWI index was associated with an increased prevalence of asthma and an older age of first asthma onset.

Bisphenol A (BPA) has transgenerational effects on the development of experimental asthma through BRD4/ZDHHC-1/STING axis

Perinatal exposures to Bisphenol A (BPA) have been associated with an increase in asthma prevalence. We have reported the increased expression of bromodomain-containing protein 4 (BRD4), zinc finger DHHC-1, and stimulators of interferon genes (STING) in BPA exposed mouse immune cells. The purpose of this study was to test the hypothesis that perinatal exposure to BPA enhances allergic asthma development through BRD4/ ZDHHC-1/STING axis.

Prevalence and Risk Factors of Asthma in Children and Adolescents in Rabigh, Western Saudi Arabia

The worldwide prevalence of asthma in children is variable. The different epidemiological definitions of asthma, the use of various methods of measurement, and the environmental variations between countries are responsible for such different prevalence rates. This study has been performed to identify the prevalence/risk factors of asthma in Saudi children/adolescents in Rabigh. A cross-sectional epidemiological survey has been conducted using the validated Arabic version of the "International Study of Asthma and Allergies in Childhood questionnaire". Data on the sociodemographic characteristics of participants and risk factors of asthma have also been collected. Three hundred and forty-nine Children/adolescents with an age range of 5-18 years have been randomly selected for an interview from public places and houses in different regions of Rabigh City. The prevalence rates of physician-diagnosed asthma, any wheezing, and wheezing in the last 12 months among children/adolescents (mean age: 12.22 ± 4.14 years) have remarkably increased in association with the rapidly developing industrialization of Rabigh from previously recorded rates of 4.9%, 7.4%, and 6.4% in the only study that has previously been conducted in Rabigh in 1998 to 31.5%, 23.5%, and 14.9%, respectively. The univariate analysis has detected some significant risk factors for asthma. However, in younger aged children (5-9 years), allergic rhinitis, associated chronic illnesses, and viral respiratory infection-induced wheezing have remained significant risk factors of any wheezing. Drug allergy, exposure to dust, and viral respiratory infection-induced wheezing have persisted as significant risk factors for wheezing in the last 12 months. Eczema in the family, exposure to perfumes/incense, and viral respiratory infection-induced wheezing have remained as significant risk factors of physician-diagnosed asthma. The results of this survey should be useful in future targeted preventive plans/measures with special attention to improving air quality to limit the progressive increase in asthma prevalence in Rabigh, as well as in other similar industrial communities.

A Cross Sectional Study of Respiratory and Allergy Status in Dairy Workers

ABSTRACT Introduction Workers on dairy farms face exposures to organic dusts and endotoxin. At the same time, a number of studies of farmers have reported a lower prevalence of asthma in farmworkers compared to persons without farm contact. The “hygiene hypothesis” suggests that early life exposures on farms could be protective against allergic disease and asthma. Such protective relationships are less well studied in adult farm workers. Methods A cross-sectional analysis of respiratory function and allergy status was performed in a sample of dairy farm workers (n = 42) and community controls (n = 40). Measures of respiratory status (spirometry, exhaled nitric oxide FeNO, self-reported symptoms) and levels of total and bovine-specific IgE were compared between the groups. Results Prevalence of self-reported asthma and most respiratory symptoms was similar in the two groups, with the exception of increased report of dyspnea among dairy workers. In the dairy workers, level of lung function was not reduced and FeNO was not increased. In unadjusted and adjusted models, dairy work was not associated with reduced lung function or increased airway inflammation. Mean IgE levels did not differ significantly between workers and controls, but elevated bovine-specific IgE was detected only among dairy workers, with an apparent association between elevated bovine IgE and increased FeNO. Conclusion While dairy workers did not demonstrate increased asthma prevalence compared to controls, sensitization to bovine antigen in several workers appeared to be associated with airway inflammation. Occupational health programs for dairy workers should consider the risk of animal allergy as part of respiratory health protection efforts.

Epidemiology of Asthma: Prevalence and Burden of Disease.

Asthma, a common airway disease, results in a significant burden to both patients and society worldwide. Yet, despite global political commitment backed by the United Nations, progress to reduce the burden of asthma remains inadequate. This is particularly true in low-income countries. To date, progress has been delayed by the lack of uniform data collection, imperfect surveillance methods, inadequate resources, poor access to effective therapies, substandard asthma education, ineffective governmental policies, rapid urbanization, progressive increase in asthma prevalence, increased life expectancy and obesity rates worldwide, asthma heterogeneity and disease complexity, smoking, and environmental exposures to allergens and pollution. A thorough understanding of the challenges facing the international community is essential to define future strategies to improve the burden of asthma.

An Elevated METS-IR Index Is Associated With Higher Asthma Morbidity and Earlier Age of First Asthma in US Adults: Results Based on a Cross-Sectional Study.

ObjectiveThe purpose of this study was to evaluate whether there is a correlation between the METS-IR index and asthma among Americans.MethodsIn an attempt to establish the relationship between the METS-IR index and asthma prevalence and age at first onset of asthma, we conducted a logistic regression analysis, subgroup analysis, and dose-response curve analysis using the National Health and Nutrition Examination Survey (NHANES) database.ResultsIn model 3, each unit increase in METS-IR index led to 1.5% increase in asthma prevalence (OR= 1.015, 95% CI: 1.012, 1.018) and an earlier age of onset of asthma by 0.057years (β= -0.057, 95% CI: -0.112, -0.002).Stratified analysis determined that an increase in METS-IR index was associated with asthma prevalence in almost all subgroups, except in the group where it was not known whether a blood relative had asthma, and a positive linear relationship was found between METS-IR index and asthma prevalence, as well as a linear negative relationship with age at asthma onset.ConclusionDespite the fact that a direct causal relationship cannot be demonstrated, a higher METS-IR index is positively related to asthma prevalence and correspondingly may result in asthma onset at younger ages.

Maternal BMI and allergy in children until 3 years of age (JECS).

Maternal prepregnancy body mass index (BMI) may influence allergic diseases in the children who are the product of those pregnancies. The purpose of our study was to investigate the association between mothers' prepregnancy BMI and the risk of physician-diagnosed asthma, food allergy (FA), and atopic dermatitis (AD) in their children during the first 3 years of life. Data on mothers' prepregnancy BMI and physician-diagnosed asthma, FA, and AD in their children until the age of 3 years were obtained from the Japan Environment and Children's Study, a nationwide birth cohort study that has recruited 103,099 pregnant women between 2011 and 2014. Logistic regression analysis was used to analyze the results. We analyzed 67,204 mother-child pairs with available information on physician-diagnosed allergic diseases. The risk of asthma was significantly higher in children born to overweight mothers (adjusted OR [aOR]=1.17 [95% CI= 1.07-1.28]) and obese mothers (aOR= 1.28 [95% CI= 1.08-1.50]), whereas the risk of FA, cow's milk allergy, and egg allergy decreased significantly in children born to overweight mothers (aOR= 0.84 [95% CI= 0.76-0.92]; aOR= 0.78 [95% CI= 0.64-0.93]; and aOR= 0.83 [95% CI= 0.74-0.94]) and obese mothers (aOR= 0.81 [95% CI= 0.67-0.97]; aOR= 0.58 [95% CI= 0.36-0.87]; and aOR= 0.73 [95% CI= 0.56-0.93]) compared with in children born to normal weight mothers, respectively. Associations between AD and maternal BMI were not detected. Our study showed that an increase in mothers' prepregnancy BMI was associated with an increase in asthma prevalence and a decrease in FA prevalence in their children. Further studies are needed to reveal the mechanisms associated with maternal BMI and pediatric allergic diseases.

Prevalence of Asthma and Its Associating Environmental Factors among 6-12-Year-Old Schoolchildren in a Metropolitan Environment-A Cross-Sectional, Questionnaire-Based Study.

We aimed to evaluate the prevalence of asthma and its associating environmental factors within a 6–12-year-old population. A cross-sectional, questionnaire-based study was conducted in primary schools located in the capital of Hungary; 3836 eligible parent-reported questionnaires were evaluated. Besides the International Study of Asthma and Allergies in Childhood (ISAAC) phase three core questions for asthma, the survey also assessed various potential risk factors. We introduced the umbrella term cumulative asthma as the union of physician-diagnosed asthma and current wheezing to estimate the lifetime prevalence of asthma. Current wheezing and physician-diagnosed asthma showed a frequency of 9.5% and 6.3%, respectively. They contributed to a cumulative asthma prevalence of 12.6% among the sampled population, with a girl-boy percentage of 37.4% to 62.6%. Air-pollution and weedy areas were associated with greater risk for asthma, while a suburban residence showed lesser odds. Indoor smoking, visible mold, and keeping a dog were defined as risk factors for asthma, while the presence of plants in the bedroom and pet rodents were associated with lower odds ratios. The consumption of fast food, beverages containing additives and margarine were significantly higher in asthmatics, while we found frequent sport activity and cereal intake associated with lower odds ratios for asthma. In this urban environment, we identified an increased asthma prevalence compared to some previously published studies, but the cross-sectional design and the different methodology did not permit us to draw timeframe-dependent conclusions.

Socioeconomic status, lifestyle factors and asthma prevalence: results from a population-based study in Sweden.

To examine differences in the prevalence of self-reported diagnosed asthma by socioeconomic status and the contribution of lifestyle factors to these differences. The study was based on 28,531 persons aged 18 years or older who answered a survey questionnaire sent to a random population sample in mid-Sweden in 2017. The overall response rate was 44%. Socioeconomic status was measured with educational level and economic difficulties, and lifestyle factors with physical activity, smoking, snuff use, risk-drinking of alcohol and obesity. The associations between socioeconomic status and asthma were analysed using multivariate logistic regression. The overall asthma prevalence was 9% among women and 7% in men and decreased with increasing age. Educational level was not independently associated with asthma, but a statistically significant odds ratio (with 95% confidence intervals) for the prevalence of asthma was observed for economic difficulties 1.5 (1.3-1.7). Also, physical inactivity 1.2 (1.1-1.3) and obesity 1.6 (1.4-1.8) were associated with increased asthma prevalence. Smoking and risk-drinking were not statistically significantly associated with asthma whereas snuff users had a higher prevalence of asthma among women. Adjusting for lifestyle factors did not affect the association between socioeconomic status and asthma. In this population-based study, self-reported diagnosed asthma was independently associated with economic difficulties but not with educational level. Lifestyle factors did not explain the association between economic difficulties and asthma prevalence. This applies to both men and women as well as younger and older age groups.

Delivery Mode and Gut Microbial Changes Correlate With an Increased Risk of Childhood Asthma

Children born via cesarean delivery have higher rates of childhood asthma. In this study, researchers examined associations between mode of delivery and the gut microbiome and tested for relationships between these changes and asthma risk.In this study, 700 children enrolled in the Copenhagen Prospective Studies on Asthma in Childhood 2010 birth cohort were included. Of these children, 151 were born via cesarean delivery, and 549 were born by vaginal delivery.In this study, researchers used a nested case-control design. All children had at least 1 fecal sample collected before 1 year of age (1 week, 1 month, and/or 1 year), analyzed by using 16S rRNA sequencing. A sparse partial least squares model was used to identify correlations between cesarean delivery and gut microbial composition at each time point. A “cesarean microbial score” was calculated for each time point, and a Kaplan-Meyer estimate was used to identify the cumulative asthma risk on the basis of delivery method and cesarean microbial score.Cesarean delivery was associated with significant increases in asthma prevalence at age 6 (odds ratio: 2.45). Cesarean delivery was also associated with marked differences in gut microbiota at 1 week and 1 month of age that became less significant by 1 year. The relationship between cesarean delivery and asthma depended on the microbiome composition at the age of 1 year. Of the children delivered by cesarean, only those who still had a significant cesarian microbiota signature at 1 year of age had higher rates of asthma at age 6 (odds ratio: 1.37).Cesarean delivery was associated with increased asthma risk but only in children who still had a cesarean gut microbial signature at 1 year of age.There is increasing evidence that early-life microbial exposures drive immune maturation and the risk of allergic diseases and asthma. With this study, the authors help to explain how delivery method influences asthma risk. In the results, it is indicated that cesarean delivery prevents the transfer of bacteria that produce short chain fatty acids in the gut to promote immune system regulation. With this observation, it is suggested that replacing these “missing bacteria” or their metabolites could reduce the risk for allergies and asthma in children born by cesarean delivery.

Lung Inflammatory Response to Environmental Dust Exposure in Mice Suggests a Link to Regional Respiratory Disease Risk.

PurposeThe Salton Sea, California’s largest lake, is designated as an agricultural drainage reservoir. In recent years, the lake has experienced shrinkage due to reduced water sources, increasing levels of aerosolized dusts in surrounding regions. Communities surrounding the Salton Sea have increased asthma prevalence versus the rest of California; however, a connection between dust inhalation and lung health impacts has not been defined.MethodsWe used an established intranasal dust exposure murine model to study the lung inflammatory response following single or repetitive (7-day) exposure to extracts of dusts collected in regions surrounding the Salton Sea (SSDE), complemented with in vitro investigations assessing SSDE impacts on the airway epithelium.ResultsIn these investigations, single or repetitive SSDE exposure induced significant lung inflammatory cytokine release concomitant with neutrophil influx. Repetitive SSDE exposure led to significant lung eosinophil recruitment and altered expression of genes associated with allergen-mediated immune response, including Clec4e. SSDE treatment of human bronchial epithelial cells (BEAS-2B) induced inflammatory cytokine production at 5- and 24-hours post-treatment. When BEAS-2B were exposed to protease activity-depleted SSDE (PDSSDE) or treated with SSDE in the context of protease-activated receptor-1 and −2 antagonism, inflammatory cytokine release was decreased. Furthermore, repetitive exposure to PDSSDE led to decreased neutrophil and eosinophilic influx and IL-6 release in mice compared to SSDE-challenged mice.ConclusionThese investigations demonstrate potent lung inflammatory responses and tissue remodeling in response to SSDE, in part due to environmental proteases found within the dusts. These studies provide the first evidence supporting a link between environmental dust exposure, protease-mediated immune activation, and respiratory disease in the Salton Sea region.

High but stable incidence of adult-onset asthma in northern Sweden over the last decades.

BackgroundThe prevalence of asthma has increased both among children and adults during the latter half of the 20th century. The prevalence among adults is affected by the incidence of asthma not only in childhood but also in adulthood. Time trends in asthma incidence have been poorly studied.AimsThe aim of this study was to review the incidence of adult-onset asthma from 1996 to 2006 and 2006 to 2016 and compare the risk factor patterns.MethodsIn the Obstructive Lung Disease in Northern Sweden (OLIN) studies, two randomly selected population-based samples in the 20–69-year age group participated in postal questionnaire surveys about asthma in 1996 (n=7104, 85%) and 2006 (n=6165, 77%). A 10-year follow-up of the two cohorts with the same validated questionnaire was performed, and 5709 and 4552 responded, respectively. Different definitions of population at risk were used in the calculations of asthma incidence. The protocol followed a study performed between 1986 and 1996 in the same area.ResultsThe crude incidence rate of physician-diagnosed asthma was 4.4 per 1000 person-years (men 3.8, women 5.5) from 1996 to 2006, and 4.8 per 1000 person-years (men 3.7, women 6.2) from 2006 to 2016. When correcting for possible under-diagnosis at study entry, the incidence rate was 2.4 per 1000 person-years from 1996 to 2006 and 2.6 per 1000 person-years from 2006 to 2016. The incidence rates were similar across age groups. Allergic rhino-conjunctivitis was the main risk factor for incident asthma in both observation periods (risk ratio 2.4–2.6).ConclusionsThe incidence of adult-onset asthma has been stable over the last two decades and has remained at a similar level since the 1980s. The high incidence contributes to the increase in asthma prevalence.