Generational Patterns of Asthma Incidence among Immigrants to Canada over Two Decades. A Population-based Cohort Study

Risk and protective factors of asthma and mental health condition multimorbidity in a national sample of Canadian children

BACKGROUND

The coexistence of childhood asthma and mental health (MH) conditions can impact management and health outcomes but we need to better understand the etiology of multimorbidity. We investigated the association between childhood asthma and MH conditions as well as the determinants of their coexistence.

METHODS

We used data from the Canadian Health Survey of Children and Youth 2019 (3-17 years; n = 47,871), a cross-sectional, nationally representative Statistics Canada dataset. Our primary outcome was condition status (no asthma or MH condition; asthma only; MH condition only; both asthma, and a MH condition (AMHM)). Predictors of condition status were assessed using multiple multinomial logistic regression. Sensitivity analyses considered individual MH conditions.

RESULTS

MH condition prevalence was almost two-fold higher among those with asthma than those without asthma (21.1% vs. 11.6%, respectively). There were increased risks of each condition category associated with having allergies, other chronic conditions, and family members smoking in the home while there were protective associations with each condition status category for being female and born outside of Canada. Four additional variables were associated with AMHM and MH condition presence with one additional variable associated with both AMHM and asthma. In sensitivity analyses, the associations tended to be similar for most characteristics, although there was some variability.

CONCLUSION

There are common risk factors of asthma and MH conditions along with their multimorbidity with a tendency for MH risk factors to be associated with multimorbidity. MH condition presence is common and important to assess among children with asthma.

Birth and Health Outcomes of Children Migrating With Parents: A Systematic Review and Meta-Analysis

Objective

To examine the birth and health outcomes of children migrating with parents internationally and domestically, and to identify whether the healthy migration effect exist in migrant children.

Methods

Five electronic databases were searched for cross-sectional, case-control, or cohort studies published from January 1, 2000 to January 30, 2021and written by English language, reporting the risk of health outcomes of migrant children (e.g., birth outcome, nutrition, physical health, mental health, death, and substance use) We excluded studies in which participants' age more than 18 years, or participants were forced migration due to armed conflict or disasters, or when the comparators were not native-born residents. Pooled odd ratio (OR) was calculated using random-effects models.

Results

Our research identified 10,404 records, of which 98 studies were retrained for analysis. The majority of the included studies (89, 91%) focused on international migration and 9 (9%) on migration within country. Compared with native children, migrant children had increased risks of malnutrition [OR 1.26 (95% CI 1.11-1.44)], poor physical health [OR 1.34 (95% CI 1.11-1.61)], mental disorder [OR 1.24 (95% CI 1.00-1.52)], and death [OR 1.11 (95% CI 1.01-1.21)], while had a lower risk of adverse birth outcome [OR 0.92 (95% CI 0.87-0.97)]. The difference of substance use risk was not found between the two groups.

Conclusion

Migrant children had increased risk of adverse health outcomes. No obvious evidence was observed regarding healthy migration effect among migrant children. Actions are required to address the health inequity among these populations.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/#myprospero, identifier: CRD42021214115.

Bioinformatic Analysis and Cellular Assays Identify Substance P Influencing Th17/Treg Differentiation via the MyD88 Pathway as a Potential Contributor to the Progression of Asthma and Allergic Rhinitis

Objective

This study is aimed at investigating the role of substance P (SP) in the development of asthma.

Methods

The Gene Expression Omnibus (GEO) database was used to characterize SP expression in allergic rhinitis (AR) and asthma. Peripheral blood was collected from patients with asthma or AR. The expression of relevant cytokines and neuropeptides was measured. Enzyme-linked immunosorbent assay (ELISA) was also performed. The mast cell line LAD2 and the lung bronchial epithelial cell line BEAS-2B were treated with different concentrations of SP concentration. Then, the qRT-PCR method was used to determine the mRNA expression. Furthermore, p38 and p65 and their associated phosphorylated proteins (p-p38 and p-p65) were further validated by western blotting.

Result

Clinical and GSE75011 data analysis suggested that MyD88 expression was upregulated in AR and asthma. Through the gene set variation analysis (GSVA), MyD88-related pathways were noticed and further investigated. ELISA results suggested that the SP expression was significantly increased in AR and asthma and IL-10 expression was decreased, whereas the expression of IL-6, IL-17A, IL-23, and TGF-β expressions increased. The mast cell line LAD2 was treated with different SP concentrations, and ELISA results showed that the expression of IL-6, IL-17A, IL-23, and TGF-β in the cell supernatant gradually increased with increasing SP concentrations, whereas that of IL-10 decreased. The lung bronchial epithelial cell line BEAS-2B was treated with different SP concentrations, and the expression of myeloid differentiation factor 88 (MyD88) and its related proteins was elevated. The expression of p38 and p-p38 proteins was elevated after SP treatment, and their expression levels elevated as SP concentrations increased. Finally, MyD88 expression at the single-cell level was also demonstrated.

Conclusion

SP may affect the cytokine expression through the MyD88 pathway, thereby influencing Th17/Treg differentiation and eventually participating in the pathological process of asthma and AR. There are many pathological similarities between allergic rhinitis (AR) and bronchial asthma. In the present study, SP was found to possibly activate downstream inflammatory signaling pathways via MyD88, thereby affecting Th17/Treg differentiation and ultimately participating in the pathological process of asthma and AR.

Childhood food insecurity and incident asthma: A population-based cohort study of children in Ontario, Canada

BACKGROUND

Childhood food insecurity has been associated with prevalent asthma in cross-sectional studies. Little is known about the relationship between food insecurity and incident asthma.

METHODS

We used administrative databases linked with the Canadian Community Health Survey, to conduct a retrospective cohort study of children <18 years in Ontario, Canada. Children without a previous diagnosis of asthma who had a household response to the Household Food Security Survey Module (HFSSM) were followed until March 31, 2018 for new asthma diagnoses using a validated administrative coding algorithm. We used multivariable Cox proportional hazard models to examine the association between food insecurity and incident asthma, and adjusted models sequentially for clinical and clinical/socioeconomic risk factors. As additional analyses, we examined associations by HFSSM respondent type, severity of food insecurity, and age of asthma diagnosis. Moreover, we assessed for interaction between food security and child's sex, household smoking status, and maternal asthma on the risk of incident asthma.

RESULTS

Among the 27,746 included children, 5.1% lived in food insecure households. Over a median of 8.34 years, the incidence of asthma was 7.33/1000 person-years (PY) among food insecure children and 5.91/1000 PY among food secure children (unadjusted hazard ratio [HR] 1.24, 95% CI 1.00 to 1.54, p = 0.051). In adjusted analyses associations were similar (HR 1.16, 95% CI 0.91 to 1.47, p = 0.24 adjusted for clinical risk factors, HR 1.24, 95% CI 0.97 to 1.60, p = 0.09 adjusted for clinical/socioeconomic factors). Associations did not qualitatively change by HFSSM respondent type, severity of food insecurity, and age of asthma diagnosis. There was no evidence of interaction in our models.

CONCLUSIONS

Food insecure children have numerous medical and social challenges. However, in this large population-based study, we did not observe that childhood food insecurity was associated with an increased risk of incident asthma when adjusted for important clinical and socioeconomic confounders.

A Current Perspective of Allergic Asthma: From Mechanisms to Management

Asthma is a result of heterogenous, complex gene-environment interactions with variable clinical phenotypes, inflammation, and remodeling. It affects more than 330 million of people worldwide throughout their educational and working lives, while exacerbations put a heavy cost/burden on productivity. Childhood asthma is characterized by a predominance of allergic sensitization and multimorbidity, while in adults polysensitization has been positively associated with asthma occurrence. Despite significant improvements in recent decades, asthma management remains challenging. Recently, a group of specialists suggested that the term "asthma" should be preferably used as a descriptive term for symptoms. Moreover, type 2 inflammation has emerged as a pivotal disease mechanism including overlapping endotypes of specific IgE production, while type 2-low asthma includes several disease endotypes. Optimal asthma control requires both appropriate pharmacological interventions, tailored to each patient, as well as trigger avoidance measures. Regular monitoring for maintenance of symptom control, preservation of lung function, and detection of treatment-related adverse effects are warranted. Allergen-specific immunotherapy and the advent of new targeted therapies for patients with difficult to control asthma offer diverse treatment options. The current review summarizes up-to-date knowledge on epidemiology, definitions, diagnosis, and current therapeutic strategies.