Exploring biopsychosocial influences on asthma expression in both the family and community context

Parasympathetic nervous system: A key role in control and mood disorders in patients with asthma

BACKGROUND

Patients with severe asthma often have uncontrolled disease and experience mood disorders, particularly anxiety and depression. The autonomic nervous system (ANS) plays an important role in asthma, mainly through the parasympathetic ANS system (PANS), which favors bronchoconstriction and mental health status.

OBJECTIVE

To evaluate the role of the activation of the PANS in uncontrolled asthma and related mood disorders.

METHODS

This was a proof-of-concept cross-sectional study that analyzed demographic and clinical variables reflecting asthma severity and control, lung function, inflammation (from induced sputum), evaluation of quality of life, and the risk for anxiety and depression according to validated questionnaires. The PANS analysis was conducted based on heart rate variability: SD of the difference between consecutive normal-to-normal (NN) intervals (SDNN), root mean square of the successive differences (RMSSD), percentage of consecutive NN intervals (pNN50), total power (TP), and respiratory-related power (Pr).

RESULTS

A total of 30 patients with asthma were grouped according to asthma control and the risk for anxiety and depression; 10 patients with uncontrolled asthma compared with the patients with controlled asthma showed significant differences (P < .05) in SDNN (26.5 [8.2] vs 42.7 [29.7]), RMSSD (14.1 [6.5] vs 24 [20]), pNN50 (0.6 [1.5] vs 6.2 [11.8]), TP (0.0005 [0.00046] vs 0.0014 [0.00085]), and Pr (0.0003 [0.00025] vs 0.0007 [0.00060]) respectively. A total of 13 patients at risk for anxiety and depression compared with the patients without showed reduced values (P < .05) for SDNN (26.5 [7.9] vs 45.6 [31.3]), pNN50 (0.75 [1.4] to 7.12 [12.6]), TP (0.0005 [0.00048] to 0.0012 [0.0008]), and Pr (0.0003 [0.00027] to 0.0008 [0.00062]).

CONCLUSION

Our results suggest that PANS activity is depressed in patients with uncontrolled asthma and common mood disorders such as depression and anxiety, and the evaluation of heart rate variability may be a useful means for follow-up of asthma control and related mood disorders.

The Great Recession and the Health of Young Children: A Fixed-Effects Analysis in Ireland

Economic recessions have been linked to adult health, but few studies have examined how recessions influence the health of young children. This study examined the impact of life transitions linked to the recent financial crisis on the health of young children in Ireland. Data came from the Growing Up in Ireland Infant Cohort Study (n = 11,134), which assessed children before (2008), during (2011), and after (2013) the Great Recession that followed the financial crisis of 2008 and incorporated questions on the impacts of the financial crisis on families. Using fixed-effects models to control for confounding, we found that a reduction in welfare benefits during the recession was associated with a significant increase in the risks of asthma (β = 0.014, 95% confidence interval (95% CI): 0.004, 0.023) and atopy (β = 0.014, 95% CI: 0.001, 0.027). While parental job loss was not associated with child health, a reduction in working hours was associated with increased reports of child health problems (β = 0.024, 95% CI: 0.004, 0.043), as were difficulties affording basic necessities (β = 0.019, 95% CI: 0.001, 0.038). Results suggest that failing to protect vulnerable families and children during economic recessions may have long-lasting implications for child health.

Harsh parent-child conflict is associated with decreased anti-inflammatory gene expression and increased symptom severity in children with asthma

Asthma is a chronic respiratory disorder that affects over 7 million children in the United States. Evidence indicates that family stressors are associated with worsening of asthma symptoms, and some research suggests that these stressful experiences engender changes in children's immune systems in ways that exacerbate airway inflammation and contribute to both acute and chronic asthma symptoms. We examined the association between observed experiences of parent-child conflict and the expression of signaling molecules involved in the transduction of anti-inflammatory signals that regulate airway inflammation and obstruction. Fifty-seven children and their parents participated in a conflict task, and coders rated interactions for evidence of harsh and supportive behaviors. Children reported on their perceptions of parental support and reported on their daily asthma symptoms for 2 weeks. We collected peripheral blood in children to measure leukocyte expression of messenger RNA for the glucocorticoid receptor and the β2-adrenergic receptor. Analyses revealed that harsh conflict behaviors were associated with decreased expression of both messenger RNAs and more severe asthma symptoms. Neither supportive behaviors nor perceived parental support was associated with gene expression or asthma symptoms. These findings suggest that harsh interactions with parents are associated with downregulation of key anti-inflammatory signaling molecules and difficulties breathing in children with asthma. Children with asthma who are also victims of maltreatment may be particularly susceptible to transcriptional changes in immune cells that could worsen asthma over time.

Family Functioning, Eosinophil Activity, and Symptoms in Children With Asthma

OBJECTIVE

We examined prospective connections among parental depressive symptoms, family dysfunction, and eosinophil activity in children with asthma.

METHODS

81 children with asthma and their parents completed two laboratory visits across a 1-year period. At baseline and 1 year later, parents reported about their depressive symptoms and family dysfunction. We collected peripheral blood in children to measure eosinophil counts and eosinophil cationic protein. Following visits, children recorded their asthma symptoms for 2 weeks.

RESULTS

After controlling for demographic and biomedical covariates, a significant T1 × T2 Family Dysfunction interaction emerged, suggesting that the links between family dysfunction at T1 and eosinophil counts and activity at T2 depended on family functioning at T2. Parental depressive symptoms were unrelated to eosinophil activity and asthma symptoms.

CONCLUSIONS

These findings suggest that improvements in family functioning are associated with decreases in eosinophil activity, which may contribute to inflammatory processes that affect airway function.

Stress and asthma: novel insights on genetic, epigenetic, and immunologic mechanisms

In the United States the economically disadvantaged and some ethnic minorities are often exposed to chronic psychosocial stressors and disproportionately affected by asthma. Current evidence suggests a causal association between chronic psychosocial stress and asthma or asthma morbidity. Recent findings suggest potential mechanisms underlying this association, including changes in the methylation and expression of genes that regulate behavioral, autonomic, neuroendocrine, and immunologic responses to stress. There is also evidence suggesting the existence of susceptibility genes that predispose chronically stressed youth to both post-traumatic stress disorder and asthma. In this review we critically examine published evidence and suggest future directions for research in this field.

Creation of synthetic homogeneous neighbourhoods using zone design algorithms to explore relationships between asthma and deprivation in Strasbourg, France

The concept of 'neighbourhood' as a unit of analysis has received considerable research attention over the last decade. Many of these studies raise the question of the influence of local characteristics on variations in health and more recently, researchers have sought to understand how the neighbourhood can influence individual health through individual behaviour. Relatively few studies discuss the question of the borders and definition of a neighbourhood but we know that the results from health or population datasets are very sensitive to how zones are constructed - part of the Modifiable Areal Unit Problem (MAUP). In reality, we know that neighbourhoods are not constrained by artificial statistical boundaries, but rather exist as complex multi-dimensional living communities. This paper tries to better represent the reality on the ground of these communities to better inform studies of health. In this work, we have developed an experimental approach for the automated design of neighbourhoods using a small tessellated cell as a basic building block. Using the software AZTool, we considered population, shape and homogeneity constraints to develop a highly innovative approach to zone construction. The paper reports the challenges and compromises involved in building these new synthetic neighbourhoods. We provide a fully worked example of how our new synthetic homogeneous zones perform using data from Strasbourg, France. We examine data on Asthma reported through calls to the emergency services, and compare these rates with an index of multiple deprivation (NDI) which we have constructed and reported elsewhere. Higher correlations between Asthma and NDI were found using our newly constructed synthetic zones than using the existing French census areas of similar size. The significance of our work is that we show that careful construction of neighbourhoods - which we claim are more realistic than census areas - can greatly aid unpacking our understanding of neighbourhood relationships between health and the social and physical environments.

Stress and the city: housing stressors are associated with respiratory health among low socioeconomic status Chicago children

Asthma disproportionately affects non-whites in urban areas and those of low socioeconomic status, yet asthma's social patterning is not well-explained by known risk factors. We hypothesized that disadvantaged urban populations experience acute and chronic housing stressors which produce psychological stress and impact health through biological and behavioral pathways. We examined eight outcomes: six child respiratory outcomes as well as parent and child general health, using data from 682 low-income, Chicago parents of diagnosed and undiagnosed asthmatic children. We created a continuous exposure, representing material, social and emotional dimensions of housing stressors, weighted by their parent-reported difficulty. We compared the 75th to the 25th quartile of exposure in adjusted binomial and negative binomial regression models. Higher risks and rates of poor health were associated with higher housing stressors for six of eight outcomes. The risk difference (RD) for poor/fair general health was larger for children [RD = 6.28 (95% CI 1.22, 11.35)] than for parents [RD = 3.88 (95% CI -1.87, 9.63)]. The incidence rate difference (IRD) for exercise intolerance was nearly one extra day per 2 weeks for the higher exposure group [IRD = 0.88 (95% CI 0.41, 1.35)]; nearly one-third extra day per 2 weeks for waking at night [IRD = 0.32 (95% CI 0.01, 0.63)]; and nearly one-third extra day per 6 months for unplanned medical visits [IRD = 0.30 (95% CI 0.059, 0.54)]. Results contribute to the conceptualization of urban stress as a "social pollutant" and to the hypothesized role of stress in health disparities. Interventions to improve asthma outcomes must address individuals' reactions to stress while we seek structural solutions to residential stressors and health inequities.

Parent perceptions of neighborhood stressors are associated with general health and child respiratory health among low-income, urban families

BACKGROUND

This cross-sectional study examines parents' perceptions of their neighborhoods and general and respiratory health among low-income Chicago families. Asthma disproportionately affects nonwhite, urban, and low socioeconomic status (SES) populations, but Chicago's burden, and the national epidemic, are not well explained by known risk factors. Urban dwellers experience acute and chronic stressors that produce psychological distress and are hypothesized to impact health through biological and behavioral pathways. Identifying factors that covary with lower SES and minority-group status-e.g., stress-is important for understanding asthma's social patterning.

METHODS

We used survey data from 319 parents of children 5-13 years with asthma/respiratory problems and principal components analysis to create exposure variables representing parents' perceptions of two aspects of neighborhoods: collective efficacy ("CE") and physical/social order ("order"). Adjusted binomial regression models estimated risk differences (RDs) and 95% confidence intervals (CIs) for eight binary outcomes.

RESULTS

Magnitude was generally as expected, i.e., RD for low- versus high- (most favorable) exposure groups (RD(low v. high)) was larger than for the middle versus high contrast (RD(mid v. high)). "Parent general health" was strongly associated with "CE" (RD(low v. high) = 20.8 [95% CI: 7.8, 33.9]) and "order" (RD(mid v. high) = 11.4 [95% CI: 2.1, 20.7]), unlike "child general health," which had nearly null associations. Among respiratory outcomes, only "waking at night" was strongly associated with "CE" (RD(low v. high) = 16.7 [95% CI: 2.8, 30.6]) and "order" (RD(low v. high) = 22.2 [95% CI: 8.6, 35.8]). "Exercise intolerance" (RD(low v. high) = 15.8 [95% CI: 2.1, 29.5]) and "controllability" (RD(mid v. high) = 12.0 [95% CI: 1.8, 22.3]) were moderately associated with "order" but not with "CE," whereas "school absences," "rescue medication use," and "unplanned visits" had nearly null associations with both exposures.

CONCLUSIONS

More negative perceptions tended to be associated with higher risk of undesirable outcomes, adding to evidence that the social environment contributes to health and supporting research on stress' health impact among disadvantaged populations. Interventions must address not only traditional "environmental" factors, but also individuals' reactions to stress and attempt to mitigate effects of stressors while structural solutions to health inequities are sought.

Asthma in Latin America: a public heath challenge and research opportunity

Asthma has emerged as an important public health problem in many Latin American countries over the past decade. In Brazil and Costa Rica, the prevalence of asthma and associated morbidity is as great or greater as reported in traditional high prevalence countries such as the US, but remains neglected as a public health priority. Asthma in Latin America is associated particularly with underprivileged populations living in cities but remains relatively rare in many rural populations. The causes of asthma in Latin America are likely to be associated with urbanization, migration, and the adoption of a modern 'Westernized' lifestyle and environmental changes that follow these processes that include changes in diet, physical activity, hygiene, and exposures to allergens, irritants, and outdoor and indoor pollutants. Because of the enormous social, genetic, and environmental contrasts within and between Latin American countries, and the large differences in prevalence associated with these differences, the investigation of asthma in Latin America provides important research opportunities to identify the social and biological mechanisms that underlie asthma development. Asthma in Latin America poses enormous challenges for health policy makers, health services, and researchers to respond to and alleviate the growing burden of asthma disability, particularly among marginalized urban populations.