Prevalence, risk factors, and clinical outcomes of atopic and nonatopic asthma among rural children

Single-cell analysis identifies distinct CD4+ T cells associated with the pathobiology of pediatric obesity-related asthma

Pediatric obesity-related asthma is characterized by non-atopic T helper 1 (Th1) inflammation and steroid resistance. CDC42 upregulation in CD4+T cells underliesTh1 inflammation but the CD4+T cell subtype(s) with CDC42 upregulation and their contribution to steroid resistance are not known. Compared to healthy-weight asthma, obesity-alone and healthy-weight controls, single-cell transcriptomics of obese asthma CD4+T cells revealed CDC42 upregulation in 3 clusters comprised of naïve and central memory T cells, which differed from the cluster enriched for Th1 responses that was comprised of effector T cells. NR3C1, coding for glucocorticoid receptor, was downregulated, while genes coding for NLRP3 inflammasome were upregulated, in clusters with CDC42 upregulation and Th1 responses. Conserved genes in these clusters correlated with pulmonary function deficits in obese asthma. These findings suggest that several distinct CD4+T cell subtypes are programmed in obese asthma for CDC42 upregulation, Th1 inflammation, and steroid resistance, and together contribute to obese asthma phenotype.

Summary

CD4+T cells from obese children with asthma are distinctly programmed for non-allergic immune responses, steroid resistance and inflammasome activation, that underlie the obese asthma phenotype.

Are higher levels of lipid profile parameters associated with increased chances of uncontrolled asthma among adults?

BACKGROUND

Studies on the relationship between asthma and various parameters of fasting lipid profile have reported conflicting results. In this study, we intend to explore this association between asthma and its level of control with fasting serum lipid profile further.

METHODS

In our observational prospective cohort study, we studied 107 known asthmatic patients presenting in large tertiary care centre of North India. Fasting serum samples for lipid profile reports of all patients were collected. Patients were divided into controlled and uncontrolled asthma groups on the basis of clinical symptoms and spirometric findings. We evaluated the statistical difference and significance for various lipid profile parameters in between two groups using an independent t-test.

RESULTS

On comparing the fasting lipid profile of 38 patients with uncontrolled asthma and 69 patients with controlled asthma, we found that serum levels of low-density lipoprotein (LDL) and ratio of total cholesterol to high-density lipoprotein (TC: HDL) were significantly higher among patients with uncontrolled asthma. On statistical analysis, their P values were 0.03 and 0.047, respectively.

CONCLUSION

Serum levels of LDL and ratio of TC: HDL were higher in patients with uncontrolled asthma.

Farm Exposures and Allergic Disease Among Children Living in a Rural Setting

OBJECTIVES

The purpose of this study was to examine the association between farm exposures and asthma and allergic disease in children while also highlighting the experiences of non-farm rural children.

METHODS

This was a cross-sectional analysis of data collected from across the province of Saskatchewan, Canada in 2014. Surveys were completed by parents of 2275 rural dwelling children (farm and non-farm) aged 0 to 17 years within 46 rural schools. Questionnaires were distributed through schools for parents to complete.

RESULTS

Asthma prevalence was 7.6%, of which 29.5% of cases were allergic. After adjustment for potential confounders, home location (farm vs non-farm) and other farm exposures were not associated with asthma and asthma phenotypes. Those who completed farm safety education were more likely to have asthma (11.7% vs. 6.7%; p = .001) compared to children without asthma. In sub-analyses among 6-12-year-old children, boys were more likely to have asthma (non-allergic) and use short-acting beta-agonists compared to girls. Doing farm work in the summer was associated with an increased risk of asthma [adjusted OR (aOR) = 1.71 (1.02-2.88); p = .041]. Doing routine chores with large animals was associated with an increased risk of asthma [aOR = 1.83 (1.07-3.15); p = .027] and allergic asthma [aOR = 2.37 (95%CI = 1.04-5.40); p = .04].

CONCLUSION

The present study showed that the prevalence of asthma and asthma phenotypes were similar between farm and non-farm rural children. There did not appear to be differential involvement in farming activities between those with and without asthma although those with asthma had more training suggesting possible attempts to mitigate harm from farm exposures.

Early-life weight gain is associated with non-atopic asthma in childhood

Background

Previous studies suggest the association between early-life weight gain and asthma. It remains unclear whether early-life weight gain is associated with atopic or non-atopic asthma. This study aimed to investigate whether early-life weight gain is associated with atopic or non-atopic asthma.

Methods

Included in this study were 1343 singleton-birth children (761 boys, 57%) born between January 2010 and December 2011 participating in the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort were evaluated by a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and interviewed by pediatricians between July 1, 2016 and May 31, 2018 at the mean age of 6.4 years. Weight gain z-scores during the first 6, 12, and 18 months of life were classified into 4 groups: slow (below −0.67), on track (−0.67 to 0.67), rapid (0.67 to 1.28), and extremely rapid (above 1.28). The main outcomes were atopic and non-atopic asthma. Asthma was defined as having physician-diagnosed asthma and the presence of wheeze or asthma exacerbations in the last 12 months. Atopy was determined by Phadiatop Infant.

Results

The extremely rapid weight gain group of children during the first 6, 12, and 18 months of life was significantly associated with an increased risk of non-atopic asthma (adjusted odd ratio [AOR], 2.14, 95% confidence interval [CI], 1.01–4.53 for the first 6 months; AOR, 2.86, 95% CI, 1.34–6.14 for the first 12 months; AOR, 3.26, 95% CI 1.49–7.15 for the first 18 months) compared with the on track group. No significant association was found in atopic asthma. A sex-stratified analysis revealed the association of early-life weight gain with non-atopic asthma was statistically significant only in boys (AOR, 4.24, 95% CI, 1.44–12.50).

Conclusion

Extremely rapid weight gain during the first 6–18 months of life was significantly associated with 2.1- to 3.3-fold increased risk of non-atopic asthma, with a more pronounced risk found in boys.

Effect of environmental exposures on allergen sensitization and the development of childhood allergic diseases: A large-scale population-based study

Background

Changing environmental factors are likely responsible for the rising prevalence of allergic diseases in children. However, whether environmental exposures induce allergen sensitizations, and which allergen sensitization is related to the development of allergic diseases, is not clear. The study is aimed to investigate the association between environmental exposure, allergen sensitization, and the development of allergic diseases for further preventive intervention.

Methods

We conducted the Taiwan Childhood Environment and Allergic diseases Study (TCEAS) in kindergarten children in Taiwan. Skin prick tests for 6 allergens were performed. Information on the development of allergic diseases and environmental exposure was collected using standardized questionnaires. Multiple logistic regressions were used to estimate the association between environmental factors, allergen sensitization, and the development of allergic diseases.

Results

A total of 3192 children were recruited. 485 (15.2%) children had atopic dermatitis (AD), 1126 (35.3%) had allergic rhinitis (AR), and 552 (17.3%) had asthma. Children with environmental tobacco smoke exposure and fungi on the house wall had a higher risk of asthma, with ORs (95% CIs) of 1.25 (1.03–1.52) and 1.22 (1.01–1.47), respectively. The mite sensitization rate was found to be the highest. Mite sensitization was associated with significant increases in the risks of AD, AR, and asthma, with ORs (95% CIs) of 2.15 (1.53–3.03), 1.94 (1.46–2.58), and 2.31 (1.63–3.29), respectively. Cockroach sensitization also increased the risk of asthma, with an OR (95% CI) of 2.38 (1.01–5.61). Mite sensitization was associated with carpet in the home and fungi on the house wall, and milk sensitization was associated with breastfeeding duration.

Conclusion

Environmental exposures play a role in the development of allergic diseases. Allergen sensitizations were associated with certain environmental exposures. Early environmental interventions are urgently needed to prevent the development of childhood allergic diseases.

Domestic Risk Factors for Atopic and non-Atopic Asthma in First Nations Children Living in Saskatchewan, Canada

Both allergic and non-allergic asthma phenotypes are thought to vary by specific housing and other indoor environmental conditions. This study evaluated risk factors for allergic asthma phenotypes in First Nation children, an understudied Canadian population with recognized increased respiratory morbidity. We conducted a cross-sectional survey with a clinical component to assess the respiratory health of 351 school-age children living on two rural reserve communities. Asthma was defined as parental report of physician diagnosed asthma or a report of wheeze in the past 12 months. Atopy was determined by a ≥ 3-mm wheal response to any of six respiratory allergens upon skin prick testing (SPT). Important domestic and personal characteristics evaluated included damp housing conditions, household heating, respiratory infections and passive smoking exposure. Asthma and atopy prevalence were 17.4% and 17.1%, respectively. Of those with asthma, 21.1% were atopic. We performed multivariate multinomial logistic regression modelling with three outcomes: non-atopic asthma, atopic asthma and no asthma for 280 children who underwent SPT. After adjusting for potential confounders, children with atopic asthma were more likely to be obese and to live in homes with either damage due to dampness (p < 0.05) or signs of mildew/mold (p = 0.06). Both natural gas home heating and a history of respiratory related infections were associated with non-atopic asthma (p < 0.01). Domestic risk factors for asthma appear to vary by atopic status in First Nations children. Determining asthma phenotypes could be useful in environmental management of asthma in this population.

Pediatric obesity-related asthma: A prototype of pediatric severe non-T2 asthma

Childhood obesity contributes to many diseases, including asthma. There is literature to suggest that asthma developing as a consequence of obesity has a nonallergic or non-T2 phenotype. In this review, obesity-related asthma is utilized as a prototype of non-T2 asthma in children to discuss several nonallergic mechanisms that underlie childhood asthma. Obesity-related asthma is associated with systemic T helper (Th)1 polarization occurring with monocyte activation. These immune responses are mediated by insulin resistance and dyslipidemia, metabolic abnormalities associated with obesity, that are themselves associated with pulmonary function deficits in obese asthmatics. As in other multifactorial diseases, there is both a genetic and an environmental contribution to pediatric obesity-related asthma. In addition to genetic susceptibility, differential DNA methylation is associated with non-T2 immune responses in pediatric obesity-related asthma. Initial investigations into the biology of non-T2 immune responses have identified the upregulation of genes in the CDC42 pathway. CDC42 is a RhoGTPase that plays a key role in Th cell physiology, including preferential naïve Th cell differentiation to Th1 cells, and cytokine production and exocytosis. Although these novel pathways are promising findings to direct targeted therapy development for obesity-related asthma to address the disease burden, there is evidence to suggest that dietary interventions, including diet modification, rather than caloric restriction alone, decrease disease burden. Adoption of a diet rich in micronutrients, including carotenoids and 25-OH cholecalciferol, a vitamin D metabolite, may be beneficial since these are positively correlated with pulmonary function indices, while being protective against metabolic abnormalities associated with the obese asthma phenotype.

Evaluation of eczema, asthma, allergic rhinitis and allergies among the grade-7 children of Iqaluit

Background

Little is known about the prevalence of asthma, allergic rhinitis, eczema and allergies among Canadian Inuit children, especially those living in the arctic and subarctic areas.

Methods

A cross-sectional study among grade seven students attending schools in Iqaluit, the capital city of Nunavut, was conducted during the 2016/2017 school year. We used the International Study of Allergy and Asthma in Children (ISAAC) questionnaire with added questions relevant to the population. In addition, skin prick tests (SPT) were conducted to test for sensitization to common food and environmental allergens.

Results

The prevalence of current asthma is 5.2%, all of them were males and 2/3 of them were Inuit and all had a previous respiratory hospitalization. Past asthma prevalence is 8.6%, 60% males and 60% Inuit. There was an inverse relationship to crowdedness possibly as a confounding factor because of getting a higher prevalence among the non-Inuit who usually live in less crowded houses. Current allergic rhinitis prevalence is 8.6%, 60% of the cases were among the mixed Inuit/Caucasian ethnicity while no cases among the non-Inuit, there was a female predominance 3:2. Past history of allergic rhinitis prevalence is 10.3%, half of the cases were among the mixed ethnicity (5.2% of that ethnicity) followed by Inuit (3.4%) and non-Inuit (1.7%), female: Male ratio 1:1. Current eczema prevalence was 27.6%, with half of the cases among the mixed ethnicity (13.8% of that group), followed by Inuit (8.6%). There was a female predominance with protective effect of exclusive breastfeeding. Past eczema prevalence 34.5%, with half of the cases were among the mixed ethnicity (17.2% of that group), followed by Inuit (10.3%). There was a female predominance. We noted a high rate of sensitization to Cat at 29.2%, most of the cases were among the mixed ethnicity, while absent sensitization to other common inhalant allergens.

Conclusion

While being cautious about firm conclusions due to the small sample size and power, the noticed variations in the prevalence and risk factors of asthma, allergic rhinitis and eczema among different ethnicities living at the same subarctic environment might be related to several possible explanations like genetic, gene-environment interaction and/or lifestyle factors, it was out of the scope of this study to determine the causality of such variation in prevalence, which emphasizes the need for further investigation.

Lipid profiles in adolescents with and without asthma: Korea National Health and nutrition examination survey data

Background

Metabolic syndrome and dyslipidemia contribute to the development of a pro-inflammatory state in asthma. However, studies investigating the association between asthma and dyslipidemia have reported conflicting results. This study aimed to uncover the relationship between asthma and lipid profiles in adolescents using a national health and nutrition survey.

Methods

This cross-sectional study analyzed the 2010–2012 Korea National Health and Nutrition Examination Survey data and included 2841 subjects aged 11–18 years with fasting blood sample data. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were analyzed. We compared asthma prevalence between high-risk and low-risk lipid groups.

Results

There were 123 adolescents with asthma and 2718 without asthma (controls). The TC/HDL-C ratio, LDL-C/HDL-C ratio, and non-HDL-C levels were significantly higher in the asthma group than in the non-asthma group (P < 0.05). The high-risk groups displayed significantly higher asthma prevalence with higher TC, TG, LDL-C, and non-HDL-C levels and TG/HDL-C ratio than the low-risk groups (P < 0.05). After adjusting for potential confounding factors, the high-risk groups were associated with asthma according to their higher TC levels (adjusted odds ratio, 1.69; 95% confidence interval, 1.012–2.822) and TG/HDL-C ratios (adjusted odds ratio, 1.665; 95% confidence interval, 1.006–2.756).

Conclusions

Asthma prevalence was greater in adolescents with a high TC level and TG/HDL-C ratio. In addition to the standard lipid profile, elevated TG/HDL-C ratio can be used as a useful additional lipid measure to evaluate interactions between dyslipidemia and asthma.

Characteristics and Outcomes of Children with Clinical History of Atopic Versus Non-atopic Asthma Admitted to a Tertiary Pediatric Intensive Care Unit

Background:

Children admitted to the Pediatric Intensive Care Unit (PICU) with status asthmaticus have variable clinical courses, and predicting their outcomes is challenging. Identifying characteristics in these patients that may require more intense intervention is important for clinical decision-making.

Objective:

This study sought to determine the characteristics and outcomes, specifically length of stay and mortality, of atopic versus non-atopic asthmatics admitted to a PICU with status asthmaticus.

Methods:

A retrospective study was conducted at a children’s hospital from November 1, 2008 to October 31, 2013. A total of 90 children admitted to the PICU were included in the analysis. Patients were divided into two groups based on the presence of specific historical data indicative of a clinical history of atopy. Children were considered to be atopic if they had a parental history of asthma, a personal history of eczema, or a combined history of wheezing (apart from colds) and allergic rhinitis (diagnosed by a medical provider). The median hospital Length Of Stay (LOS), PICU LOS, cardiopulmonary arrest, and mortality were compared between atopic and non-atopic asthma groups. Regression models were used to estimate the LOS stratified by atopic or non-atopic and by history of intubation in present hospitalization.

Results:

Median hospital LOS for atopic children was 5.9 days (IQR of 3.8-8.7) and 3.5 days (IQR of 2.2-5.5) for non-atopic asthmatics (z = 2.9, p = 0.0042). The median PICU LOS was 2.5 days (IQR 1.4-6.1) for atopic asthmatics and 1.6 days (IQR 1.1-2.4) for non-atopic asthmatics (z = 2.5, p = 0.0141). The median LOS was significantly higher for atopic intubated patients compared to non-atopic intubated patients (p=0.021). Although there was an increased tendency towards intubation in the atopic group, the difference was not significant. There was no significant difference in cardiopulmonary arrest or mortality.

Conclusion:

A clinical history of atopic asthma in children admitted to the PICU with status asthmaticus was associated with longer length of stays The longest LOS was observed when atopic patients required intubation.

Effect of childhood BMI on asthma: a systematic review and meta-analysis of case-control studies

Background

Asthma is a multifactorial syndrome that threatens the health of children. Body mass index (BMI) might be one of the potential factors but the evidence is controversial. The aim of this study is to perform a comprehensive meta-analysis to investigate the association between asthma and BMI.

Methods

Electronic databases including, Web of Science, Pubmed, Scopus, Science Direct, ProQuest, up to April 2017, were searched by two researchers independently. The keywords “asthma, body mass index, obesity, overweight, childhood and adolescence” were used. Random and fixed effects models were applied to obtain the overall odds ratios (ORs) and standardized mean difference (SMD). Heterogeneity between the studies was examined using I² and Cochrane Q statistics.

Results

After reviewing 2511 articles, 16 studies were eligible for meta-analysis according to inclusion/exclusion criteria. A meta-analysis from 11 case-control studies revealed OR of asthma and overweight as OR = 1.64; (95% Confidence Interval (CI): 1.13–2.38) and from 14 case-control studies, OR for asthma and obesity was OR = 1.92 (95% CI: 1.39–2.65), which indicated that risk of asthma in overweight and obese children and adolescence was significantly higher (1.64 and 1.92 times) than that of individuals with (p-value < 0.01 for underweight/normal weight in both cases). Furthermore, there was a significant relationship between asthma and BMI > 85 percentile according to SMD SMD = 0.21; (95%CI: 0.03–0.38; p-value = 0.021).

Conclusions

The results showed a significant relationship between BMI (obesity/overweight) and asthma among children and adolescents. It is important to study the confounding factors that affect the relationship between asthma and BMI in future epidemiological researches.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1093-z) contains supplementary material, which is available to authorized users.

The current prevalence of asthma, allergic rhinitis, and eczema related symptoms in school-aged children in Costa Rica

OBJECTIVE

Asthma prevalence in Costa Rica is among the highest worldwide. We aimed to determine the prevalence of asthma among school-age children in the Central Highland Area of Costa Rica.

METHODS

Cross-sectional study using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was performed. Parents or guardians of children aged 6-13 years completed written questionnaires.

RESULTS

Total of 2817 school-aged children returned these questionnaires (74.1% return rate). The prevalence of asthma, rhinitis, and eczema was 21.9%, 42.6%, and 19.2%, respectively. The co-existence of the 3 diseases was seen in 22.6% of children with asthma. Boys had a slightly higher prevalence of these conditions, and younger children had higher prevalence of asthma and eczema, but lower prevalence of rhinitis than older children. The use of acetaminophen and antibiotics in the first 12 months of life showed a significant association with the prevalence of asthma, rhinitis, and eczema. Wheezing with exercise, dry cough at night, and ever rhinitis was highly associated with asthma symptoms in the last 12 months. In contrast, no association was found between children exposed to smoking at home. Frequent traffic next to the house was reported more frequently by the parents of children with asthma, although no significant association was found.

CONCLUSION

The prevalence of asthma showed a significant decrease compared to previous studies. However, there was an unexpected high prevalence of rhinitis. Exposure to acetaminophen and antibiotic during the first year of life was highly associated with asthma symptoms.

Prevalence of asthma and associated factors among male late adolescents in Tabriz, Iran

Asthma is an important chronic disease all over the world. The aim of this study was to determine the prevalence of asthma in a population of male late adolescents and its association with some contributing risk factors in northwest of Iran. This cross-sectional study was carried out in selected high schools of Tabriz, Iran, in 2016. The asthma prevalence and patient background information were examined using a questionnaire that prepared by the ISAAC. One hundred forty-two out of 1134 subjects (12.4%) identified to have asthma, 23.3% had history of current wheeze, and 16.3% had wheezing in the previous year. Family history of asthma was present in 17.1% of the participants; prevalence of active smoking in the study subjects was 3.1%; 25.1% of all subjects had exposure to secondhand tobacco smoke and keeping pets at home was present in 9.1%. Excess weight (overweight and obesity) was positively associated with prevalence of asthma (p < 0.001). No statistically significant associations were observed between asthma and father's education level (p = 0.570), mother's education level (p = 0.584), type of birth subjects (p = 0.571), and time spent outdoors during a full day (p = 0.863). Our results suggest that family history of asthma and atopy, exposure to secondhand tobacco smoke, active smoking, amount of automobile traffic around subjects' home, and keeping pets at homes are important risk factors for asthma, while time spent outdoors, educations of parents, and delivery type (normal vaginal delivery vs. C-section) subjects are not. Therefore, decreased of exposure to some environmental risk factors could be effective to reduce rate of the prevalence of asthma and wheeze.

Rural and Urban Residence During Early Life is Associated with Risk of Inflammatory Bowel Disease: A Population-Based Inception and Birth Cohort Study

OBJECTIVES

To determine the association between inflammatory bowel disease (IBD) and rural/urban household at the time of diagnosis, or within the first 5 years (y) of life.

METHODS

Population-based cohorts of residents of four Canadian provinces were created using health administrative data. Rural/urban status was derived from postal codes based on population density and distance to metropolitan areas. Validated algorithms identified all incident IBD cases from administrative data (Alberta: 1999-2008, Manitoba and Ontario: 1999-2010, and Nova Scotia: 2000-2008). We determined sex-standardized incidence (per 100,000 patient-years) and incident rate ratios (IRR) using Poisson regression. A birth cohort was created of children in whom full administrative data were available from birth (Alberta 1996-2010, Manitoba 1988-2010, and Ontario 1991-2010). IRR was calculated for residents who lived continuously in rural/urban households during each of the first 5 years of life.

RESULTS

There were 6,662 rural residents and 38,905 urban residents with IBD. Incidence of IBD per 100,000 was 33.16 (95% CI 27.24-39.08) in urban residents, and 30.72 (95% CI 23.81-37.64) in rural residents (IRR 0.90, 95% CI 0.81-0.99). The protective association was strongest in children <10 years (IRR 0.58, 95% CI 0.43-0.73) and 10-17.9 years (IRR 0.72, 95% CI 0.64-0.81). In the birth cohort, comprising 331 rural and 2,302 urban residents, rurality in the first 1-5 years of life was associated with lower risk of IBD (IRR 0.75-0.78).

CONCLUSIONS

People living in rural households had lower risk of developing IBD. This association is strongest in young children and adolescents, and in children exposed to the rural environment early in life.