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Adolescents / Chronic Illnesses / Family Influences / Inflammation / Publications — No Comments
15
Sep 15

Chronic traffic-related air pollution and stress interact to predict biologic and clinical outcomes in asthma

Background: Previous research has documented effects of both physical and social environmental exposures on childhood asthma. However, few studies have considered how these two environments might interact to affect asthma. Objective: This study aimed to test interactions between chronic exposure to traffic-related air pollution and chronic family stress in predicting biologic and clinical outcomes in children with asthma. Method: Children with asthma (n = 73, 9-18 years of age) were interviewed about life stress, and asthma-relevant inflammatory markers [cytokine production, immunoglobulin E (IgE), eosinophil counts] were measured. Parents reported on children’s symptoms. Children completed daily diaries of symptoms and peak expiratory flow rate (PEFR) measures at baseline and 6 months later. Exposure to traffic-related air pollution was assessed using a land use regression model for nitrogen dioxide concentrations. Results: NO(2) by stress interactions were found for interleukin-5 (beta for interaction term = -0.31, p = 0.02), IgE (interaction beta = -0.29, p = 0.02), and eosinophil counts (interaction beta = -0.24, p = 0.04). These interactions showed that higher chronic stress was associated with heightened inflammatory profiles as pollution levels decreased. Longitudinally, NO(2) by stress interactions emerged for daily diary symptoms (interaction beta = -0.28, p = 0.02), parent-reported symptoms (interaction beta = -0.25, p = 0.07), and PEFR (interaction beta = 0.30, p = 0.03). These interactions indicated that higher chronic stress was associated with increases over time in symptoms and decreases over time in PEFR as pollution levels decreased. Conclusions: The physical and social environments interacted in predicting both biologic and clinical outcomes in children with asthma, suggesting that when pollution exposure is more modest, vulnerability to asthma exacerbations may be heightened in children with higher chronic stress.

CITATION: Chen, E., Schreier, H. M. C., Strunk, R. C., & Brauer, M. (2008). Chronic traffic-related air pollution and stress interact to predict biologic and clinical outcomes in asthma. Environmental Health Perspectives, 116(7), 970-975.

Publications — No Comments
15
Sep 15

Mercury and psychosocial stress exposure interact to predict maternal ambulatory cortisol during pregnancy

Background: Disrupted maternal prenatal cortisol production influences offspring development. Factors influencing the hypothalamic-pituitary-adrenal axis include social (e.g., stressful life events) and physical/chemical (e.g., toxic metals) pollutants. Mercury (Hg) is a common contaminant of fish and exposure is widespread in the US. No prior study has examined the joint associations of stress and mercury with maternal cortisol profiles in pregnancy. Objectives: To investigate potential synergistic influences of prenatal stress and Hg exposures on diurnal cortisol in pregnant women. Methods: Analyses included 732 women (aged 27.4 ± 5.6 years) from a Mexico City pregnancy cohort. Participants collected saliva samples on two consecutive days (mean 19.52 ± 3.00 weeks gestation) and reported life stressors over the past 6 months. Hg was assessed in toe nail clippings collected during pregnancy. Results: There were no main effects of Hg or psychosocial stress exposure on diurnal cortisol (ps > .20) but strong evidence of interaction effects on cortisol slope (interaction B = .006, SE = .003, p = .034) and cortisol at times 1 and 2 (interaction B = -.071, SE = .028, p = .013; B = -.078, SE = .032, p  = .014). Women above the median for Hg and psychosocial stress exposure experienced a blunted morning cortisol response compared to women exposed to higher stress but lower Hg levels. Conclusions: Social and physical environmental factors interact to alter aspects of maternal diurnal cortisol during pregnancy. Research focusing solely on either domain may miss synergistic influences with potentially important consequences to the offspring.

CITATION: Schreier, H. M. C., Hsu, H.-H., Amarasiriwardena, C., Coull, B. A., Schnaas, L., Tellez-Rojo, M. M., Tamayo y Ortiz, M., Wright, R. J., & Wright, R. O. (2015). Mercury and psychosocial stress exposure interact to predict maternal ambulatory cortisol during pregnancy. Environmental Health, 14(28).

Chronic Illnesses / Publications / Socioeconomic Status — No Comments
09
Sep 15

Socioeconomic status and the health of youth: A multi-level, multi-domain approach to conceptualizing pathways

Previous research has clearly established associations between low socioeconomic status (SES) and poor youth physical health outcomes. This article provides an overview of the main pathways through which low SES environments come to influence youth health. We focus on 2 prevalent chronic health problems in youth today, asthma and obesity. We review and propose a model that encompasses (a) multiple levels of influence, including the neighborhood, family and person level; (b) both social and physical domains in the environment; and finally (c) dynamic relationships between these factors. A synthesis of existing research and our proposed model draw attention to the notion of adverse physical and social exposures in youth’s neighborhood environments altering family characteristics and youth psychosocial and behavioral profiles, thereby increasing youth’s risk for health problems. We also note the importance of acknowledging reciprocal influences across levels and domains (e.g., between family and child) that create self-perpetuating patterns of influence that further accentuate the impact of these factors on youth health. Finally, we document that factors across levels can interact (e.g., environmental pollution levels with child stress) to create unique, synergistic effects on youth health. Our model stresses the importance of evaluating influences on youth’s physical health not in isolation but in the context of the broader social and physical environments in which youth live. Understanding the complex relationships between the factors that link low SES to youth’s long-term health trajectories is necessary for the creation and implementation of successful interventions and policies to ultimately reduce health disparities.

CITATION: Schreier, H. M. C. & Chen, E. (2013). Socioeconomic status and the health of youth: A multi-level, multi-domain approach to conceptualizing pathways. Psychological Bulletin, 139(3), 606-654.

Chronic Illnesses / Publications — No Comments
15
Sep 14

Does the social environment contribute to asthma?

The impact of the social environment on asthma has recently begun to receive increasing attention. This article reviews the current literature to investigate the impact of the social environment at three levels-the neighborhood level, the peer level, and the family level-and to explore pathways through which the social environment “gets under the skin” to impact asthma onset and morbidity. Research to date suggests that adverse social conditions at the neighborhood and family levels impact asthma morbidity through direct effects on physiologic systems as well as by altering health behaviors. The impact on asthma of social networks, such as friendships, is less clear and will need to be investigated further. Future research will need to take into account the impact of the social environment to develop more comprehensive models of asthma pathogenesis.

CITATION: Chen, E., Schreier, H. M. C. (2008). Does the social environment contribute to asthma? Immunology and Allergy Clinics of North America, 28, 649-664.

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