Epidemiology of stress and asthma: from constricting communities and fragile families to epigenetics

Prenatal and postnatal stress and asthma in children: Temporal- and sex-specific associations

BACKGROUND

Temporal- and sex-specific effects of perinatal stress have not been examined for childhood asthma.

OBJECTIVES

We examined associations between prenatal and/or postnatal stress and children's asthma (n = 765) and effect modification by sex in a prospective cohort study.

METHODS

Maternal negative life events were ascertained prenatally and postpartum. Negative life event scores were categorized as 0, 1 to 2, 3 to 4, or 5 or greater to assess exposure-response relationships. We examined effects of prenatal and postnatal stress on children's asthma by age 6 years, modeling each as independent predictors, mutually adjusting for prenatal and postnatal stress, and finally considering interactions between prenatal and postnatal stress. Effect modification by sex was examined in stratified analyses and by fitting interaction terms.

RESULTS

When considering stress in each period independently, among boys, a dose-response relationship was evident for each level increase on the ordinal scale prenatally (odds ratio [OR], 1.38; 95% CI, 1.06-1.79; P value for trend = .03) and postnatally (OR, 1.53; 95% CI, 1.16-2.01; P value for trend = .001); among girls, only the postnatal trend was significant (OR, 1.60; 95% CI, 1.14-2.22; P value for trend = .005). Higher stress in both the prenatal and postnatal periods was associated with increased odds of receiving a diagnosis of asthma in girls (OR, 1.37; 95% CI, 0.98-1.91; Pinteraction = .07) but not boys (OR, 1.08; 95% CI, 0.82-1.42; Pinteraction = .61).

CONCLUSIONS

Although boys were more vulnerable to stress during the prenatal period, girls were more affected by postnatal stress and cumulative stress across both periods in relation to asthma. Understanding sex and temporal differences in response to early-life stress might provide unique insight into the cause and natural history of asthma.

Neighborhood and Individual Socioeconomic Status and Asthma Incidence in African American Women

OBJECTIVE

Individual socioeconomic status (SES) has been associated with asthma incidence but whether neighborhood SES has an influence is unknown. We assessed the contributions of neighborhood socioeconomic status (SES), neighborhood housing density, neighborhood racial composition, and individual SES to the development of adult-onset asthma in Black women, accounting for other known or suspected risk factors.

DESIGN AND PARTICIPANTS

Prospective cohort study conducted among 47,779 African American women followed with biennial health questionnaires from 1995 to 2011.

METHODS AND MAIN OUTCOME MEASURES

Incident asthma was defined as new self-report of doctor-diagnosed asthma with concurrent use of asthma medication. We assessed neighborhood SES, indicated by census variables representing income, education, and wealth, and housing density and % African American population, as well as individual SES, indicated by highest education of participant/spouse. Cox proportional hazards models were used to derive multivariable hazard ratios (HRs) and 95% CIs for the association of individual SES and neighborhood variables with asthma incidence.

RESULTS

During a 16-year follow-up period, 1520 women reported incident asthma. Neighborhood factors were not associated with asthma incidence after control for individual SES, body mass index, and other factors. Compared with college graduates, the multivariable HR for asthma was 1.13 (95% CI 1.00-1.28) for women with some college education and 1.23 (95% CI 1.05-1.44) for women with no more than a high school education.

CONCLUSIONS

Individual SES, but not neighborhood SES or other neighborhood factors, was associated with the incidence of adult-onset asthma in this population of African American women.

Children's Environmental Health: A Brief History

BACKGROUND

Children's environmental health (CEH), the branch of pediatrics that studies the influence of the environment on children's health, has grown substantially in the past 3 decades and become an increasingly visible and important component of pediatric medicine.

GOALS

To trace the historical origins of CEH; to identify factors responsible for its recent growth.

FINDINGS

CEH has historical roots in toxicology, epidemiology, and occupational medicine. It arose in the second half of the 20th century through a melding of insights from pediatric toxicology, nutritional epidemiology, and social science research. Convergent research in these 3 fields has documented children's unique sensitivities to chemical, nutritional, and psychosocial hazards during windows of vulnerability in early development and has shown that early-life exposures can produce disease and disability in childhood and across the life span. Key events in the development of CEH were: 1) formation by the American Academy of Pediatrics in 1957 of a committee on environmental health that has nurtured the growth of the field for 5 decades and evolved into the Council on Environmental Health; 2) observations made in the 1980s that nutritional deficiency in utero increased risk for adult-onset obesity, diabetes, and cardiovascular disease-work that led to the hypothesis of the developmental origins of health and disease; 3) social science research showing that early exposure to psychosocial stress and trauma increases risk for chronic illness; and 4) publication in 1993 by the National Academy of Sciences of a report, Pesticides in the Diets of Infants and Children, which elevated awareness among national policy makers of children's vulnerability to toxic hazards, moved US environmental policy toward protection of children's health, and catalyzed research investment in CEH in the United States and globally.

CONCLUSIONS

CEH has made substantial progress but faces emerging challenges, including new chemicals and pesticides; increasing movement of polluting industries to poor countries where environmental and public health protections are few; and global climate change. In the future, CEH will require continued investment in research and education and will need to adopt an increasingly global perspective.

Relationships between Psychosocial Resilience and Physical Health Status of Western Australian Urban Aboriginal Youth

BACKGROUND

Psychosocial processes are implicated as mediators of racial/ethnic health disparities via dysregulation of physiological responses to stress. Our aim was to investigate the extent to which factors previously documented as buffering the impact of high-risk family environments on Aboriginal youths' psychosocial functioning were similarly beneficial for their physical health status.

METHOD AND RESULTS

We examined the relationship between psychosocial resilience and physical health of urban Aboriginal youth (12-17 years, n = 677) drawn from a representative survey of Western Australian Aboriginal children and their families. A composite variable of psychosocial resilient status, derived by cross-classifying youth by high/low family risk exposure and normal/abnormal psychosocial functioning, resulted in four groups- Resilient, Less Resilient, Expected Good and Vulnerable. Separate logistic regression modeling for high and low risk exposed youth revealed that Resilient youth were significantly more likely to have lower self-reported asthma symptoms (OR 3.48, p<.001) and carer reported lifetime health problems (OR 1.76, p<.04) than Less Resilient youth.

CONCLUSION

The findings are consistent with biopsychosocial models and provide a more nuanced understanding of the patterns of risks, resources and adaptation that impact on the physical health of Aboriginal youth. The results support the posited biological pathways between chronic stress and physical health, and identify the protective role of social connections impacting not only psychosocial function but also physical health. Using a resilience framework may identify potent protective factors otherwise undetected in aggregated analyses, offering important insights to augment general public health prevention strategies.

The association of intrafamilial violence against children with symptoms of atopic and non-atopic asthma: A cross-sectional study in Salvador, Brazil

This study aims to describe the types of intrafamilial violence perpetrated against children according to living conditions, family factors, and child characteristics, and to identify the association between types of intrafamilial violence and asthma symptoms in atopic and non-atopic children. A cross-sectional study was carried out with 1,370 caregivers as part of the Social Changes, Asthma and Allergy in Latin America (SCAALA) study, conducted in 2006 in Brazil. The study population was selected by random sampling. The main outcome measures were atopic and non-atopic asthma. We investigate the association between intrafamilial violence and asthma symptoms in atopic and non-atopic children. A backward multivariate logistic polytomous regression was performed to verify the main association. Nonviolent discipline (NVD) and maltreatment nonviolent discipline (MNVD) were positively associated with non-atopic asthma symptoms (NVD: odds ratio (OR)=1.95/95% confidence interval (CI)=1.17-3.25; MNVD: OR=1.95/95% CI=1.19-3.20). However, for the most severe intrafamilial violence, this association was not found after control of potential confounders. This study demonstrates the effect of types of intrafamilial violence on non-atopic asthma. Intrafamilial violence against children represents one more component in the determination of non-atopic asthma in Latin America.

Maternal intimate partner violence exposure, child cortisol reactivity and child asthma

Psychosocial stressors like intimate partner violence (IPV) exposure are associated with increased risk of childhood asthma. Longitudinal studies have not investigated the role of hypothalamic-pituitary-adrenal (HPA) axis reactivity (and associated alterations in cortisol release) in the child IPV exposure-asthma association. We sought to investigate this association, and to assess whether this relationship differs by child HPA reactivity. This secondary analysis used longitudinal cohort data from the Family Life Project. Participants included 1,292 low-income children and mothers; maternal interview and child biomarker data, including maternal report of IPV and child asthma, and child salivary cortisol obtained with validated stress reactivity paradigms, were collected when the child was 7, 15, 24, 35, and 48 months. Using structural equation modeling, maternal IPV when the child was 7 months of age predicted subsequent reports of childhood asthma (B=0.18, p=.002). This association differed according to the child's HPA reactivity status, with IPV exposed children who were HPA reactors at 7 and 15 months of age--defined as a ≥10% increase in cortisol level twenty minutes post peak arousal during the challenge tasks and a raw increase of at least .02μg/dl--being significantly at risk for asthma (7 months: B=0.17, p=.02; 15 months: B=0.17, p=.02). Our findings provide support that children who are physiologically reactive are the most vulnerable to adverse health outcomes when faced with environmental stressors.

Epigenetics and Understanding the Impact of Social Determinants of Health

Recently, a new research agenda emphasizing interactions between social factors and health has emerged. The term social determinant of health often refers to any nonmedical factor directly influencing health. Health across the life span is strongly and adversely affected by social disadvantage. Research in epigenetics indicates that alterations in DNA methylation may provide a causal link between social adversity and health disparity. Likewise, accelerated loss of telomeres is correlated with chronic stress. Research is still required to develop an understanding of the role of epigenetics and perturbed telomere function in linking social adversity with health outcome.

Increased Risk of Asthma in Children with ADHD: Role of Prematurity and Maternal Stress during Pregnancy

OBJECTIVE

ADHD and asthma are prevalent conditions in childhood, with complex pathophysiology involving genetic-environmental interplay. The study objective is to examine the prevalence of asthma in our ADHD population and explore factors that may increase the risk of developing asthma in children with ADHD.

METHODS

We retrospectively analyzed the presence of maternal stress during pregnancy and history of asthma in 201 children diagnosed with ADHD.

RESULTS

Chi-square analysis indicated significant higher presence of asthma in our ADHD sample compared to Quebec children, χ(2)(1, N = 201) = 15.37, P<0.001. Only prematurity and stress during pregnancy significantly predicted asthma in a logistic regression model, χ(2)(2)=23.70, P<0.001, with odds ratios of 10.6 (95% CI: 2.8-39.5) and 3.2 (95% CI: 1.4-7.3), respectively.

CONCLUSION

Children with ADHD have a higher prevalence of asthma than the general Quebec pediatric population. Children with ADHD born prematurely and/or those whose mothers experienced stress during pregnancy have a significantly increased risk of developing asthma. The study highlights the importance of potentially offering social and psychological support to mothers who experienced stress during pregnancy and/or are at risk of delivering prematurely.

Epigenetic: A missing paradigm in cellular and molecular pathways of sulfur mustard lung: a prospective and comparative study

Sulfur mustard (SM, bis- (2-chloroethyl) sulphide) is a chemical warfare agent that causes DNA alkylation, protein modification and membrane damage. SM can trigger several molecular pathways involved in inflammation and oxidative stress, which cause cell necrosis and apoptosis, and loss of cells integrity and function. Epigenetic regulation of gene expression is a growing research topic and is addressed by DNA methylation, histone modification, chromatin remodeling, and noncoding RNAs expression. It seems SM can induce the epigenetic modifications that are translated into change in gene expression. Classification of epigenetic modifications long after exposure to SM would clarify its mechanism and paves a better strategy for the treatment of SM-affected patients. In this study, we review the key aberrant epigenetic modifications that have important roles in chronic obstructive pulmonary disease (COPD) and compared with mustard lung.

Prenatal stress and childhood asthma in the offspring: role of age at onset

BACKGROUND

Asthma is a heterogeneous disorder with different phenotypes, and age at onset may define part of them. Little is known about possible association between prenatal stress and asthma phenotypes according to age at onset. We aim to investigate whether there is an association between prenatal stress and asthma, and if so, whether such an association differs according to age at asthma onset.

METHODS

We carried out a cohort study based on several national registers in Denmark, including all live singletons born during 1996-2007 in Denmark (N = 750,058). We identified children born to mothers who lost a close relative (a child, partner/spouse, a parent or a sibling) 1 year prior to or during pregnancy as the bereaved group. Using Cox proportional hazards regression model, we evaluated the hazard ratios (HRs) for asthma in children of bereaved mothers, compared with children of non-bereaved mothers.

RESULTS

Prenatal stress following maternal bereavement was associated with a marginally increased risk of asthma events in children aged 0-3 years [HR = 1.04, 95% confidence interval (CI): 1.00-1.07], while unexpected bereavement was associated with a higher risk (HR = 1.13, 95% CI: 1.02-1.24). There was no association between prenatal bereavement and asthma in children aged 4-15 years (HR = 1.02, 95% CI: 0.96-1.09).

CONCLUSIONS

Prenatal stress is possibly associated with asthma events in children aged 0-3 years, but not with asthma in children aged 4-15 years irrespective of age at asthma onset.

Review of family relational stress and pediatric asthma: the value of biopsychosocial systemic models

Asthma is the most common chronic disease in children. Despite dramatic advances in pharmacological treatments, asthma remains a leading public health problem, especially in socially disadvantaged minority populations. Some experts believe that this health gap is due to the failure to address the impact of stress on the disease. Asthma is a complex disease that is influenced by multilevel factors, but the nature of these factors and their interrelations are not well understood. This paper aims to integrate social, psychological, and biological literatures on relations between family/parental stress and pediatric asthma, and to illustrate the utility of multilevel systemic models for guiding treatment and stimulating future research. We used electronic database searches and conducted an integrated analysis of selected epidemiological, longitudinal, and empirical studies. Evidence is substantial for the effects of family/parental stress on asthma mediated by both disease management and psychobiological stress pathways. However, integrative models containing specific pathways are scarce. We present two multilevel models, with supporting data, as potential prototypes for other such models. We conclude that these multilevel systems models may be of substantial heuristic value in organizing investigations of, and clinical approaches to, the complex social-biological aspects of family stress in pediatric asthma. However, additional systemic models are needed, and the models presented herein could serve as prototypes for model development.

Have recent investigations into remission from childhood asthma helped in understanding the pathogenesis of this disease?

Studies show that a significant proportion of young people suffering from childhood onset asthma later recovered, usually in adolescence. In this article we argue that an understanding of the differences between children who recover from asthma and those who do not would contribute to increased understanding of the pathogenic mechanisms of the disease and could provide new clues about prevention and treatment. We note that some researchers have recently published results from these kinds of investigations. This paper reports results regarding genetic determinants, distorted mechanisms of inflammation, and mind/body relationships. We also try to integrate findings from these 3 areas to formulate general conclusions about the pathogenesis of asthma.

Targeted rejection predicts decreased anti-inflammatory gene expression and increased symptom severity in youth with asthma

Although responses to different stressors are sometimes assumed to be similar, recent research has demonstrated that certain types of stress, such as targeted rejection, are particularly potent. To test such associations in a chronic-disease model, we examined how noninterpersonal, interpersonal, and targeted-rejection major life events predicted changes in gene expression and symptom severity in 121 youths with asthma who were assessed every 6 months for 2 years. Youths who had recently experienced targeted rejection had lower messenger RNA expression for signaling molecules that control airway inflammation and obstruction (specifically, the glucocorticoid receptor and β2-adrenergic receptor) than youths who had not experienced targeted rejection. These associations were specific to targeted rejection and stronger for youths higher in subjective social status. Higher-status youths exposed to targeted rejection (but not other types of stress) also reported more asthma symptoms. These data demonstrate stressor-specific associations with molecular-signaling pathways and the severity of asthma, and they suggest that threats to the social self may be particularly deleterious.

Perceived neighborhood safety and asthma morbidity in the school inner-city asthma study

AIM

The aim of this study was to investigate whether neighborhood safety as perceived by primary caregivers is associated with asthma morbidity outcomes among inner-city school children with asthma.

METHODS

School children with asthma were recruited from 25 inner-city schools between 2009 and 2012 for the School Inner-City Asthma Study (N = 219). Primary caregivers completed a baseline questionnaire detailing their perception of neighborhood safety and their children's asthma symptoms, and the children performed baseline pulmonary function tests. In this cross-sectional analysis, asthma control was compared between children whose caregivers perceived their neighborhood to be unsafe versus safe.

RESULTS

After adjusting for potential confounders, those children whose primary caregivers perceived the neighborhood to be unsafe had twice the odds of having poorly controlled asthma (odds ratio [OR] adjusted = 2.2, 95% confidence interval [CI] = 1.2-3.9, P = 0.009), four times the odds of dyspnea and rescue medication use (OR adjusted = 4.7; 95% CI = 1.7-13.0, P = 0.003, OR adjusted = 4.0; 95% CI = 1.8-8.8, P < 0.001, respectively), three times as much limitation in activity (OR adjusted = 3.2; 95% CI = 1.4-7.7, P = 0.008), and more than twice the odds of night-time symptoms (OR adjusted = 2.2; 95% CI = 1.3-4.0, P = 0.007) compared to participants living in safe neighborhoods. There was no difference in pulmonary function test results between the two groups.

CONCLUSIONS

Primary caregivers' perception of neighborhood safety is associated with childhood asthma morbidity among inner-city school children with asthma. Further study is needed to elucidate mechanisms behind this association, and future intervention studies to address social disadvantage may be important.

Homes of low-income minority families with asthmatic children have increased condition issues

The home is increasingly associated with asthma. It acts both as a reservoir of asthma triggers and as a refuge from seasonal outdoor allergen exposure. Racial/ethnic minority families with low incomes tend to reside in neighborhoods with low housing quality. These families also have higher rates of asthma. This study explores the hypothesis that black and Latino urban households with asthmatic children experienced more home mechanical, structural condition-related areas of concern than white households with asthmatic children. Participant families (n = 140) took part in the Kansas City Safe and Healthy Homes Program, had at least one asthmatic child, and met income qualifications of no more than 80% of local median income; many were below 50%. Families self-identified their race. Homes were assessed by environmental health professionals using a standard set of criteria and a specific set of on-site and laboratory sampling and analyses. Homes were given a score for areas of concern between 0 (best) and 53 (worst). The study population self-identified as black (46%), non-Latino white (26%), Latino (14.3%), and other (12.9%). Mean number of areas of concern were 18.7 in Latino homes, 17.8 in black homes, 13.3 in other homes, and 13.2 in white homes. Latino and black homes had significantly more areas of concern. White families were also more likely to be in the upper portion of the income. In this set of 140 low-income homes with an asthmatic child, households of minority individuals had more areas of condition concerns and generally lower income than other families.

The role of social toxicity in responses to a slowly-evolving environmental disaster: the case of amphibole asbestos exposure in Libby, Montana, USA

Experiencing a disaster has significant negative effects on psychological adjustment. Case study accounts point to two consistent trends in slowly-evolving environmental disasters: (a) patterns of negative social dynamics, and (b) relatively worse psychological outcomes than in natural disasters. Researchers have begun to explicitly postulate that the social consequences of slowly-evolving environmental disasters (e.g., community conflict) have their own effects on victims' psychological outcomes. This study tested a model of the relationship between those social consequences and psychological adjustment of victims of a slowly-evolving environmental disaster, specifically those whose health has been compromised by the amphibole asbestos disaster in Libby, MT. Results indicate that experiencing greater community conflict about the disaster was associated with greater family conflict about the disaster which, in turn, was associated with greater social constraints on talking with others about their disease, both directly and indirectly through experiencing stigmatization. Experiencing greater social constraints was associated with worse psychological adjustment, both directly and indirectly through failed social support. Findings have implications for understanding pathways by which social responses create negative effects on mental health in slowly-evolving environmental disasters. These pathways suggest points for prevention and response (e.g., social support, stigmatization of victims) for communities experiencing slowly-evolving environmental disasters.

Work-related psychosocial stress as a risk factor for asthma, allergy, and respiratory infections in the Swedish workforce

This study examined the association between work-related psychosocial stress and asthma, atopy, and respiratory infections. 532 randomly selected occupationally active people (272 men, 260 women; M age = 41 yr., SD = 13) in Sweden participated. Information on history of asthma, atopy, and respiratory infections was collected by a postal self-report questionnaire. Work stress was assessed based on the demands-control-support model. Current asthma and respiratory infections were associated with work-related psychosocial stress. When stratified for sex, these associations were only found in men. Associations between low control, low support, and current asthma were found among young participants (< 40 years), whereas among older participants (> 40 years) low supervisor support was associated with frequent respiratory infections.

Job strain and the risk of severe asthma exacerbations: a meta-analysis of individual-participant data from 100 000 European men and women

Background

Many patients and healthcare professionals believe that work‐related psychosocial stress, such as job strain, can make asthma worse, but this is not corroborated by empirical evidence. We investigated the associations between job strain and the incidence of severe asthma exacerbations in working‐age European men and women.

Methods

We analysed individual‐level data, collected between 1985 and 2010, from 102 175 working‐age men and women in 11 prospective European studies. Job strain (a combination of high demands and low control at work) was self‐reported at baseline. Incident severe asthma exacerbations were ascertained from national hospitalization and death registries. Associations between job strain and asthma exacerbations were modelled using Cox regression and the study‐specific findings combined using random‐effects meta‐analyses.

Results

During a median follow‐up of 10 years, 1 109 individuals experienced a severe asthma exacerbation (430 with asthma as the primary diagnostic code). In the age‐ and sex‐adjusted analyses, job strain was associated with an increased risk of severe asthma exacerbations defined using the primary diagnostic code (hazard ratio, HR: 1.27, 95% confidence interval, CI: 1.00, 1.61). This association attenuated towards the null after adjustment for potential confounders (HR: 1.22, 95% CI: 0.96, 1.55). No association was observed in the analyses with asthma defined using any diagnostic code (HR: 1.01, 95% CI: 0.86, 1.19).

Conclusions

Our findings suggest that job strain is probably not an important risk factor for severe asthma exacerbations leading to hospitalization or death.

Prenatal maternal stress predicts childhood asthma in girls: project ice storm

Little is known about how prenatal maternal stress (PNMS) influences risks of asthma in humans. In this small study, we sought to determine whether disaster-related PNMS would predict asthma risk in children. In June 1998, we assessed severity of objective hardship and subjective distress in women pregnant during the January 1998 Quebec Ice Storm. Lifetime asthma symptoms, diagnoses, and corticosteroid utilization were assessed when the children were 12 years old (N = 68). No effects of objective hardship or timing of the exposure were found. However, we found that, in girls only, higher levels of prenatal maternal subjective distress predicted greater lifetime risk of wheezing (OR = 1.11; 90% CI = 1.01-1.23), doctor-diagnosed asthma (OR = 1.09; 90% CI = 1.00-1.19), and lifetime utilization of corticosteroids (OR = 1.12; 90% CI = 1.01-1.25). Other perinatal and current maternal life events were also associated with asthma outcomes. Findings suggest that stress during pregnancy opens a window for fetal programming of immune functioning. A sex-based approach may be useful to examine how prenatal and postnatal environments combine to program the immune system. This small study needs to be replicated with a larger, more representative sample.

Environmental exposures and asthma morbidity in children living in urban neighborhoods

A substantial disparity in asthma prevalence and morbidity among urban children compared with their nonurban counterparts has been recognized for more than two decades. Because of the nature of urban neighborhoods, pest allergens, such as cockroach and mouse, are present in high concentrations in US urban housing and have both repeatedly been linked to asthma morbidity in sensitized children. In addition, there is a growing body of evidence demonstrating that concentrations of many pollutants are higher indoors than outdoors in both US and European urban communities and that exposures to indoor pollutants such as particulate matter (PM) and nitrogen dioxide (NO2 ) are independently associated with symptoms in children with asthma. Although environmental interventions are challenging to implement, when they reduce relevant indoor allergen and pollutant exposures, they are associated with clear improvements in asthma. Other modifiable risk factors in urban childhood asthma that have emerged include dietary and nutritional factors. Overweight and obese children, for example, may be more susceptible to the pulmonary effects of pollutant exposure. Insufficiency of vitamin D and folate has also emerged as modifiable risk factors for asthma morbidity in children. The identification of these modifiable risk factors for urban childhood asthma morbidity offers a ripe opportunity for intervention.

Experiences of racism and the incidence of adult-onset asthma in the Black Women's Health Study

BACKGROUND

Chronic stress resulting from experiences of racism may increase the incidence of adult-onset asthma through effects on the immune system and the airways. We conducted prospective analyses of the relation of experiences of racism with asthma incidence in the Black Women's Health Study, a prospective cohort of black women in the United States followed since 1995 with mailed biennial questionnaires.

METHODS

Among 38,142 participants followed from 1997 to 2011, 1,068 reported incident asthma. An everyday racism score was created based on five questions asked in 1997 and 2009 about the frequency in daily life of experiences of racism (eg, poor service in stores), and a lifetime racism score was based on questions about racism on the job, in housing, and by police. We used Cox regression models to derive multivariable incidence rate ratios (IRRs) and 95% CIs for categories of each racism score in relation to incident asthma.

RESULTS

The IRRs were 1.45 (95% CI, 1.19-1.78) for the highest compared with the lowest quartile of the 1997 everyday racism score (P for trend<.0001) and 1.44 (95% CI, 1.18-1.75) for the highest compared with the lowest category of 1997 lifetime racism. Among women who reported the same levels of racism in 1997 and 2009, the IRRs for the highest categories of everyday and lifetime racism were 2.12 (95% CI, 1.55-2.91) and 1.66 (95% CI, 1.20-2.30), respectively.

CONCLUSIONS

Given the high prevalence of experiences of racism and asthma in black women in the United States, a positive association between racism and asthma is of public health importance.

The relationships between ambient air pollutants and childhood asthma and eczema are modified by emotion and conduct problems

PURPOSE

This study examined the hypothesis that emotion and conduct problems (ECPs) may modify the relationships between ambient air pollutants and childhood asthma and eczema.

METHODS

In the cross-sectional study, 4209 French schoolchildren (aged 10e12 years) were investigated between March 1999 and October 2000. Ambient air pollutants exposures were estimated with dispersion modeling. Health outcomes and ECPs were evaluated by validated questionnaires, completed by the parents. Marginal models were used to analyze the relationships of exposures to ambient air pollutants and/or ECPs to asthma phenotypes and current eczema, adjusting for potential confounders.

RESULTS

In our population, interactions were found between ECPs and exposures to ambient air pollutants (benzene, carbon monoxide, nitrogen dioxide, nitrogen oxides, particulate matter with an aerodynamic diameter below 10 mm, volatile organic compounds) (P < .20). In addition, ECPs were related to current wheezing (adjusted prevalence odds ratio [aOR], 2.35; 95% confidence interval [CI], 1.59e3.47), current doctor-diagnosed asthma (aOR, 1.82; 95% CI, 1.25e2.66), and current eczema (aOR, 2.21; 95% CI, 1.61e3.02). Children with ECPs had 1.17e1.51 times higher aORs for the associations between ambient air pollutants and asthma phenotypes and current eczema than those without ECPs.

CONCLUSIONS

ECPs may modify the relationships between ambient air pollutants and childhood asthma and eczema.

Prenatal adverse life events increase the risk for atopic diseases in children, which is enhanced in the absence of a maternal atopic predisposition

BACKGROUND

There is evidence to suggest an association between prenatal maternal stress and the development of asthma or other atopic diseases in offspring. Yet, insights on the lasting effect of multiple, common prenatal stressors are rare, and the effects of prenatal timing are poorly understood. Further, it remains elusive if prenatal life events modify the risk for atopic diseases in the context of a parental predisposition to atopy.

OBJECTIVE

We tested whether women's experiences of common, adverse life events during the first or second half of pregnancy predicted the risk of developing atopic diseases in their children and whether a reported parental atopic disease moderated this association.

METHODS

We calculated the odds of a child developing asthma, eczema, and/or allergic rhinitis at ages 6 or 14 years, depending on maternal prenatal exposure to negative life events in a sample of 1587 children from the Western Australian Pregnancy Cohort (Raine) Study by using multivariable logistic regression.

RESULTS

We observed that the likelihood of asthma and eczema at age 14 years was significantly increased in children of mothers who had experienced adverse life events during the second half of gestation (1 life event: adjusted odds ratio for asthma, 2.08 [95% CI, 1.22-3.54]). A stronger increase in the odds to develop asthma upon prenatal life events was present in children of mothers without asthma compared with mothers with asthma.

CONCLUSIONS

Maternal adverse life events during the second half of gestation are linked to an increased risk for the development of atopic disorders, asthma, and eczema, in the case of asthma, particularly in the absence of a maternal asthma.

Childhood adversity and asthma prevalence: evidence from 10 US states (2009-2011)

Background

Existing evidence on stress and asthma prevalence has disproportionately focused on pregnancy and postpregnancy early life stressors, largely ignoring the role of childhood adversity as a risk factor. Childhood adversity (neglect, stressful living conditions and maltreatment) may influence asthma prevalence through mechanisms on the hypothalamic-pituitary axis.

Methods

Data from the Center for Disease Control's (CDC's) Behavioral Risk Factor Surveillance System (BRFSS) surveys were used to examine cross-sectional associations of adverse childhood experiences (ACE) with lifetime and current asthma prevalence. Information on childhood adversity was available from 84 786 adult respondents in 10 US states. Poisson regression models (with robust SE) were used to estimate prevalence ratios (PRs) relating overall ACE score and dimensions of exposure ACE to asthma prevalence, adjusting for socioeconomic status.

Results

Greater ACE was associated with a higher prevalence of asthma (adjusted PR_{cat 4}=1.78 (95% CI 1.69 to 1.87), adjusted PR_{cat 1}=1.21 (95% CI 1.16 to 1.27)). Reported experiences of sexual abuse (adjusted PR=1.48* (1.42 to 1.55)) and physical abuse (adjusted PR=1.38* (1.33 to 1.43)) were associated with a higher asthma prevalence. No clear socioeconomic gradient was noted, but those reporting lowest education and income levels reported high rates of asthma and adversity. Sensitivity analyses indicated that ACE exposures were interrelated.

Conclusions

Report of childhood adversity predicts asthma prevalence among US adults. Frameworks for asthma prevention need to recognise and integrate aspects related to childhood adversity. Further investigation into specific time periods of exposure would provide meaningful inferences for interventions.

Role of financial and social hardships in asthma racial disparities

BACKGROUND AND OBJECTIVES

Health care reform offers a new opportunity to address child health disparities. This study sought to characterize racial differences in pediatric asthma readmissions with a focus on the potential explanatory role of hardships that might be addressed in future patient care models.

METHODS

We enrolled 774 children, aged 1 to 16 years, admitted for asthma or bronchodilator-responsive wheezing in a population-based prospective observational cohort. The outcome was time to readmission. Child race, socioeconomic status (measured by lower income and caregiver educational attainment), and hardship (caregivers looking for work, having no one to borrow money from, not owning a car or home, and being single/never married) were recorded. Analyses used Cox proportional hazards.

RESULTS

The cohort was 57% African American, 33% white, and 10% multiracial/other; 19% were readmitted within 12 months. After adjustment for asthma severity classification, African Americans were twice as likely to be readmitted as whites (hazard ratio: 1.98; 95% confidence interval: 1.42 to 2.77). Compared with whites, African American caregivers were significantly more likely to report lower income and educational attainment, difficulty finding work, having no one to borrow money from, not owning a car or home, and being single/never married (all P ≤ .01). Hardships explained 41% of the observed racial disparity in readmission; jointly, socioeconomic status and hardship explained 49%.

CONCLUSIONS

African American children were twice as likely to be readmitted as white children; hardships explained >40% of this disparity. Additional factors (eg, pollution, tobacco exposure, housing quality) may explain residual disparities. Targeted interventions could help achieve greater child health equity.

Prenatal environmental factors influencing IgE levels, atopy and early asthma

PURPOSE OF REVIEW

There is increasing evidence that the prenatal window represents a critical period in which the developing immune system may be primed toward an allergic phenotype. Studies have investigated the role of a number of maternal environmental exposures on subsequent allergic disorders in the offspring. We summarize findings from recent studies on prenatal environmental factors influencing IgE levels, atopy, and early asthma.

RECENT FINDINGS

A building literature supports the influence of maternal exposure to environmental pollutants, such as allergens, traffic-related air pollution, tobacco smoke, and organochlorine compounds and social factors on allergic outcomes. More novel associations have been investigated, such as the effect of prenatal exposures to phthalates, bisphenol A, and magnetic fields. There is also rising interest in epigenetics as a pathway of action by which maternal exposure affect immune health.

SUMMARY

Emerging research highlights the challenges of investigating in-utero exposures and of relating exposures to such a heterogeneous and complex outcome as allergic disease. Further research is needed on the mechanisms by which prenatal exposure influences allergic response in childhood and how postnatal, familial and social factors, and sex can modify disease outcomes. Epigenetics is a promising new frontier, and likely one of several explanatory factors.

Parental psychological distress during pregnancy and wheezing in preschool children: the Generation R Study

BACKGROUND

Maternal psychological distress during pregnancy might affect fetal lung development and subsequently predispose children to childhood asthma.

OBJECTIVE

We sought to assess the associations of maternal psychological distress during pregnancy with early childhood wheezing.

METHODS

We performed a population-based prospective cohort study among 4848 children. We assessed maternal and paternal psychological distress at the second trimester of gestation and 3 years after delivery and maternal psychological distress at 2 and 6 months after delivery by using the Brief Symptom Inventory questionnaire. Wheezing in the children was annually examined by using questionnaires from 1 to 4 years. Physician-diagnosed ever asthma was reported at 6 years.

RESULTS

Mothers with psychological distress during pregnancy had increased odds of wheezing in their children from 1 to 4 years of life (overall distress: odds ratio [OR], 1.60 [95% CI, 1.32-1.93]; depression: OR, 1.46 [95% CI, 1.20-1.77]; and anxiety: OR, 1.39 [95% CI, 1.15-1.67]). We observed similar positive associations with the number of wheezing episodes, wheezing patterns, and physician-diagnosed asthma at 6 years. Paternal distress during pregnancy and maternal and paternal distress after delivery did not affect these results and were not associated with childhood wheezing.

CONCLUSION

Maternal psychological distress during pregnancy is associated with increased odds of wheezing in their children during the first 6 years of life independent of paternal psychological distress during pregnancy and maternal and paternal psychological distress after delivery. These results suggest a possible intrauterine programming effect of maternal psychological distress leading to respiratory morbidity.

The observed association between maternal anxiety and adolescent asthma: children of twin design suggest familial effects

Background

Previous studies indicate that maternal anxiety is associated with asthma in the adolescent child, but mechanisms are unclear.

Objective

To investigate the association between maternal anxiety and maternal, self- and register-based report of asthma in the adolescent child, and whether the association remains after control of familial confounding (shared environmental and genetic factors).

Method

From the Twin and Offspring Study of Sweden, 1691 mothers (1058 twins) and their adolescent child were included. The association between maternal self-reported anxiety (Beck Anxiety Inventory (BAI) and Karolinska Scales of Personality (KSP) somatic or psychic anxiety) and asthma based on subjective (maternal or child report) or objective (register-based diagnosis and medication) measures were analysed using logistic regression. The children-of-twins design was used to explore whether genes or environment contribute to the association.

Results

Maternal BAI anxiety (OR 2.02, CI 1.15–3.55) was significantly associated with adolescent asthma reported by the mother. Maternal KSP somatic anxiety (OR 1.74, CI 1.04–2.91) and psychic anxiety (OR 1.74, CI 1.05–2.86) was significantly associated with breathlessness reported by the adolescent child. In contrast, maternal anxiety was not associated with increased risk for the register-based outcomes of asthma diagnosis or medication. The results remained also after adjusting for covariates and the children-of-twins analyses which indicate that the association was due to familial confounding.

Conclusions

We found some associations between maternal anxiety and subjectively reported offspring asthma or breathlessness which may be due to familial effects. A likely candidate for explaining this familial confounding is heritable personality traits associated with both anxiety and subjective measures of asthma.

Effects of glucocorticoid treatment given in early or late gestation on growth and development in sheep

Antenatal corticosteroids are used to augment fetal lung maturity in human pregnancy. Dexamethasone (DEX) is also used to treat congenital adrenal hyperplasia of the fetus in early pregnancy. We previously reported effects of synthetic corticosteroids given to sheep in early or late gestation on pregnancy length and fetal cortisol levels and glucocorticoids alter plasma insulin-like growth factor (IGF) and insulin-like growth factor binding protein (IGFBP) concentrations in late pregnancy and reduce fetal weight. The effects of administering DEX in early pregnancy on fetal organ weights and betamethasone (BET) given in late gestation on weights of fetal brain regions or organ development have not been reported. We hypothesized that BET or DEX administration at either stage of pregnancy would have deleterious effects on fetal development and associated hormones. In early pregnancy, DEX was administered as four injections at 12-hourly intervals over 48 h commencing at 40–42 days of gestation (dG). There was no consistent effect on fetal weight, or individual fetal organ weights, except in females at 7 months postnatal age. When BET was administered at 104, 111 and 118 dG, the previously reported reduction in total fetal weight was associated with significant reductions in weights of fetal brain, cerebellum, heart, kidney and liver. Fetal plasma insulin, leptin and triiodothyronine were also reduced at different times in fetal and postnatal life. We conclude that at the amounts given, the sheep fetus is sensitive to maternal administration of synthetic glucocorticoid in late gestation, with effects on growth and metabolic hormones that may persist into postnatal life.

DNA methylation program during development

DNA methylation is a key epigenetic mark when occurring in the promoter and enhancer regions regulates the accessibility of the binding protein and gene transcription. DNA methylation is inheritable and can be de novo-synthesized, erased and reinstated, making it arguably one of the most dynamic upstream regulators for gene expression and the most influential pacer for development. Recent progress has demonstrated that two forms of cytosine methylation and two pathways for demethylation constitute ample complexity for an instructional program for orchestrated gene expression and development. The forum of the current discussion and review are whether there is such a program, if so what the DNA methylation program entails, and what environment can change the DNA methylation program. The translational implication of the DNA methylation program is also proposed.

Geomedicine: area-based socioeconomic measures for assessing risk of hospital reutilization among children admitted for asthma

OBJECTIVES

We assessed whether geographic information available at the time of asthma admission predicts time to reutilization (readmission or emergency department revisit).

METHODS

For a prospective cohort of children hospitalized with asthma in 2008 and 2009 in Cincinnati, Ohio, we constructed a geographic social risk index from geocoded home addresses linked to census tract extreme poverty and high school graduation rates and median home values. We examined geographic risk associations with reutilization and caregiver report of hardship.

RESULTS

Thirty-nine percent of patients reutilized within 12 months. Compared with those in the lowest geographic risk stratum, those at medium and high risk had 1.3 (95% confidence interval [CI] = 0.9, 1.9) and 1.8 (95% CI = 1.4, 2.4) the risk of reutilization, respectively. Caregivers of children at highest geographic risk were 5 times as likely to report more than 2 financial hardships (P < .001) and 3 times as likely to report psychological distress (P = .001).

CONCLUSIONS

A geographic social risk index may help identify asthmatic children likely to return to the hospital. Targeting social risk assessments and interventions through geographic information may help to improve outcomes and reduce disparities.

Allostatic load biomarkers and asthma in adolescents

RATIONALE

Allostatic load (AL), a novel measure of the physiologically dysregulated response of the body to stress, represents a biomarker of chronic stress exposure.

OBJECTIVES

To determine whether preadolescent children with high AL are more susceptible to asthma as adolescents.

METHODS

This was a prospective evaluation of children recruited at 7 to 10 years of age in the nested case-control arm of the Study of Asthma, Genes and Environment and followed until 11 to 14 years of age. AL was measured using eight biomarkers: fasting glucose, total cholesterol, high-density lipoprotein cholesterol, dehydroepiandrosterone sulfate, cortisol, systolic and diastolic blood pressure, and waist-to-hip ratio. AL, created from the sum of biomarkers in a high-risk quartile, was related to prevalence and incidence of asthma using logistic regression.

MEASUREMENTS AND MAIN RESULTS

Among 352 participants followed until 11 to 14 years of age, prevalent asthma was four times more likely in boys with high (>3) versus low (≤2) AL after adjusting for current asthma/atopy, age, ethnicity, parental history of asthma, and overweight status. Similar results were observed in the analysis of new-onset asthma in boys (adjusted odds ratio, 4.35; 95% confidence interval, 1.19-15.9). In girls, there were no associations between AL and asthma. In the analysis of a subset of biomarkers, combinations of total cholesterol, glucose, and cortisol were associated with similar or greater risk of asthma prevalence or onset in boys.

CONCLUSIONS

AL and its biomarkers are associated with an increased likelihood of asthma in adolescent boys. The observed association between AL and asthma may be attributable to a combined subset of AL biomarkers.

Psychosocial stress and asthma morbidity

PURPOSE OF REVIEW

The objective of this review is to provide an overview and discussion of recent epidemiologic and mechanistic studies of stress in relation to asthma incidence and morbidity.

RECENT FINDINGS

Recent findings suggest that stress, whether at the individual (i.e. epigenetics, perceived stress), family (i.e. prenatal maternal stress, early-life exposure, or intimate partner violence) or community (i.e. neighborhood violence; neighborhood disadvantage) level, influences asthma and asthma morbidity. Key recent findings regarding how psychosocial stress may influence asthma through Posttraumatic Stress Disorder, prenatal and postnatal maternal/caregiver stress, and community violence and deprivation are highlighted.

SUMMARY

New research illustrates the need to further examine, characterize, and address the influence of social and environmental factors (i.e. psychological stress) on asthma. Further, research and innovative methodologies are needed to characterize the relationship and pathways associated with stress at multiple levels to more fully understand and address asthma morbidity, and to design potential interventions, especially to address persistent disparities in asthma in ethnic minorities and economically disadvantaged communities.

Family functioning style and health: opportunities for health prevention in primary care

BACKGROUND

The relationship between family and health has not been studied in detail in primary care.

AIM

To evaluate the association between family functioning style and health problems among families receiving primary care.

DESIGN AND SETTING

Cross-sectional study in an underserved primary care clinic in Santiago, Chile.

METHOD

Families registered at the Juan Pablo II Primary Care Clinic in Santiago, Chile from 2006 to 2010 formed the study sample. Each family selected an adult family member to answer a questionnaire to provide data on: family sociodemographics; health problems among family members; and the family functioning style, as assessed with the Family Functioning Style Scale (FFSS). The t-test was used to assess differences in family functioning styles between families with and without health problems, and analysis of variance was used to study the relationship between the family functioning style and the number of health problems present.

RESULTS

A total of 6202 families, comprising 25 037 people, were assessed. The following diseases and conditions were examined: in children--asthma or recurrent bronchitis, delayed development, enuresis or encopresis, behavioural problems, overweight; in adolescents and adults--teenage pregnancy, asthma or chronic obstructive pulmonary disease, smoking, hypertension, type 2 diabetes, major depression, alcohol or drug abuse, and frailty. Families with health problems had a significantly lower FFSS score than families without health conditions. Mental health diseases had the strongest association with family functioning style. An inverse relationship between the number of health problems and the FFSS score was also observed.

CONCLUSION

A better family functioning style was associated with a lower prevalence of health problems in families. Bases for further research considering the family as a target for clinical interventions are provided.

Environmental chemical exposures and human epigenetics

Every year more than 13 million deaths worldwide are due to environmental pollutants, and approximately 24% of diseases are caused by environmental exposures that might be averted through preventive measures. Rapidly growing evidence has linked environmental pollutants with epigenetic variations, including changes in DNA methylation, histone modifications and microRNAs. Environ mental chemicals and epigenetic changes All of these mechanisms are likely to play important roles in disease aetiology, and their modifications due to environmental pollutants might provide further understanding of disease aetiology, as well as biomarkers reflecting exposures to environmental pollutants and/or predicting the risk of future disease. We summarize the findings on epigenetic alterations related to environmental chemical exposures, and propose mechanisms of action by means of which the exposures may cause such epigenetic changes. We discuss opportunities, challenges and future directions for future epidemiology research in environmental epigenomics. Future investigations are needed to solve methodological and practical challenges, including uncertainties about stability over time of epigenomic changes induced by the environment, tissue specificity of epigenetic alterations, validation of laboratory methods, and adaptation of bioinformatic and biostatistical methods to high-throughput epigenomics. In addition, there are numerous reports of epigenetic modifications arising following exposure to environmental toxicants, but most have not been directly linked to disease endpoints. To complete our discussion, we also briefly summarize the diseases that have been linked to environmental chemicals-related epigenetic changes.

Child asthma and change in elevated depressive symptoms among mothers of children of a birth cohort from Quebec

The authors examined the association between maternal reports of child asthma attacks since birth and occurrence of elevated maternal depressive symptoms at seventeen months postpartum in the present study. The modifying role of poverty in this association was also examined. Data from n = 1,696 mother-child dyads from the Quebec Longitudinal Study of Child Development, a birth cohort of children born in 1998, were used. Maternal depressive symptoms were measured with an abridged and validated twelve-item version of the Center for Epidemiologic Studies Depression Scale. Maternal reports of child asthma attacks since birth in relation to the occurrence of maternal depressive symptoms at 17 months postpartum and the potential modifying role of poverty were tested using multiple logistic regression models. When mothers reported child asthma attacks, those without elevated depressive symptoms at 5 months postpartum had lower odds of elevated depressive symptoms one year later (OR = 0.2, 95% CI: 0.1-0.7). Poverty was associated with increased odds of elevated maternal depressive symptoms (OR = 2.4, 95% CI: 1.5-3.9), without interacting with child asthma. Through this study, the authors suggest that in mothers without elevated symptoms at 5 months, reported child asthma attacks since birth did not contribute one year later to new occurrence of depressive symptoms.

Early life exposures: impact on asthma and allergic disease

PURPOSE OF REVIEW

To identify and discuss recent studies relating prenatal and early-life environmental exposures to the development of asthma and allergic disease.

RECENT FINDINGS

New studies show that prenatal and early-life stress can alter infant immune profiles, increasing risk for asthma and allergy. Mounting evidence implicates indoor and outdoor air pollution in the origins of allergic disease, while Vitamin D intake and a Mediterranean diet may be protective. The role of early-life fever and infection remain controversial, with recent studies yielding conflicting results and new evidence indicating that previous studies may have been confounded. New studies are increasingly focused on environmental 'imprinting' of the infant gut microbiota, which is a critical determinant of immune system development. Early exposures impacting the intestinal microbiota include mode of delivery, infant diet, and use of antibiotics - factors that are also associated with childhood asthma and allergic disease.

SUMMARY

This overview highlights environmental exposures during the in-utero and ex-utero time periods that are potential stimuli for the early programming of asthma and allergy. Special consideration is given for the potential role of intestinal microbiota. Future studies in this field promise to inform health policy and intervention strategies for the prevention of asthma and allergic disease.

Maternal educational level, parental preventive behavior, risk behavior, social support and medical care consumption in 8-month-old children in Malmö, Sweden

Background

The social environment in which children grow up is closely associated with their health. The aim of this study was to investigate the relationship between maternal educational level, parental preventive behavior, parental risk behavior, social support, and use of medical care in small children in Malmö, Sweden. We also wanted to investigate whether potential differences in child medical care consumption could be explained by differences in parental behavior and social support.

Methods

This study was population-based and cross-sectional. The study population was 8 month-old children in Malmö, visiting the Child Health Care centers during 2003-2007 for their 8-months check-up, and whose parents answered a self-administered questionnaire (n = 9,289 children).

Results

Exclusive breast feeding ≥4 months was more common among mothers with higher educational level. Smoking during pregnancy was five times more common among less-educated mothers. Presence of secondhand tobacco smoke during the first four weeks of life was also much more common among children with less-educated mothers. Less-educated mothers more often experienced low emotional support and low practical support than mothers with higher levels of education (>12 years of education). Increased exposure to unfavorable parental behavioral factors (maternal smoking during pregnancy, secondhand tobacco smoke and exclusive breastfeeding <4 months) was associated with increased odds of in-hospital care and having sought care from a doctor during the last 8 months. The odds were doubled when exposed to all three risk factors. Furthermore, children of less-educated mothers had increased odds of in-hospital care (OR = 1.34 (95% CI: 1.08, 1.66)) and having sought care from a doctor during the last 8 months (OR = 1.28 (95% CI: 1.09, 1.50)), which were reduced and turned statistically non-significant after adjustment for unfavorable parental behavioral factors.

Conclusion

Children of less-educated mothers were exposed to more health risks, fewer health-promoting factors, worse social support, and had higher medical care consumption than children with higher educated mothers. After adjustment for parental behavioral factors the excess odds of doctor's visits and in-hospital care among children with less-educated mothers were reduced. Improving children's health calls for policies targeting parents' health-related behaviors and social support.