Air Pollution–Associated Changes in Lung Function among Asthmatic Children in Detroit

In a longitudinal cohort study of primary-school–age children with asthma in Detroit, Michigan, we examined relationships between lung function and ambient levels of particulate matter ≤ 10 μm and ≤ 2.5 μm in diameter (PM(10) and PM(2.5)) and ozone at varying lag intervals using generalized estimating equations. Models considered effect modification by maintenance corticosteroid (CS) use and by the presence of an upper respiratory infection (URI) as recorded in a daily diary among 86 children who participated in six 2-week seasonal assessments from winter 2001 through spring 2002. Participants were predominantly African American from families with low income, and > 75% were categorized as having persistent asthma. In both single-pollutant and two-pollutant models, many regressions demonstrated associations between higher exposure to ambient pollutants and poorer lung function (increased diurnal variability and decreased lowest daily values for forced expiratory volume in 1 sec) among children using CSs but not among those not using CSs, and among children reporting URI symptoms but not among those who did not report URIs. Our findings suggest that levels of air pollutants in Detroit, which are above the current National Ambient Air Quality Standards, adversely affect lung function of susceptible asthmatic children

Influence of viral infection on the relationships between airway cytokines and lung function in asthmatic children

Abstract Background Few longitudinal studies examine inflammation and lung function in asthma. We sought to determine the cytokines that reduce airflow, and the influence of respiratory viral infections on these relationships. Methods Children underwent home collections of nasal lavage during scheduled surveillance periods and self-reported respiratory illnesses. We studied 53 children for one year, analyzing 392 surveillance samples and 203 samples from 85 respiratory illnesses. Generalized estimated equations were used to evaluate associations between nasal lavage biomarkers (7 mRNAs, 10 proteins), lung function and viral infection. Results As anticipated, viral infection was associated with increased cytokines and reduced FVC and FEV1. However, we found frequent and strong interactions between biomarkers and virus on lung function. For example, in the absence of viral infection, CXCL10 mRNA, MDA5 mRNA, CXCL10, IL-4, IL-13, CCL4, CCL5, CCL20 and CCL24 were negatively associated with FVC. In contrast, during infection, the opposite relationship was frequently found, with IL-4, IL-13, CCL5, CCL20 and CCL24 levels associated with less severe reductions in both FVC and FEV1. Conclusions In asthmatic children, airflow obstruction is driven by specific pro-inflammatory cytokines. In the absence of viral infection, higher cytokine levels are associated with decreasing lung function. However, with infection, there is a reversal in this relationship, with cytokine abundance associated with reduced lung function decline. While nasal samples may not reflect lower airway responses, these data suggest that some aspects of the inflammatory response may be protective against viral infection. This study may have ramifications for the treatment of viral-induced asthma exacerbations.https://deepblue.lib.umich.edu/bitstream/2027.42/146519/1/12931_2018_Article_922.pd

Neighbourhood socioeconomic disadvantage and fruit and vegetable consumption:a seven countries comparison

BACKGROUND: Low fruit and vegetable consumption is a risk factor for poor health. Studies have shown consumption varies across neighbourhoods, with lower intakes in disadvantaged neighbourhoods. However, findings are inconsistent, suggesting that socio-spatial inequities in diet could be context-specific, highlighting a need for international comparisons across contexts. This study examined variations in fruit and vegetable consumption among adults from neighbourhoods of varying socioeconomic status (SES) across seven countries (Australia, Canada, Netherlands, New Zealand, Portugal, Scotland, US). METHODS: Data from seven existing studies, identified through literature searches and knowledge of co-authors, which collected measures of both neighbourhood-level SES and fruit and vegetable consumption were used. Logistic regression was used to examine associations between neighbourhood-level SES and binary fruit and vegetable consumption separately, adjusting for neighbourhood clustering and age, gender and education. As much as possible, variables were treated in a consistent manner in the analysis for each study to allow the identification of patterns of association within study and to examine differences in the associations across studies. RESULTS: Adjusted analyses showed evidence of an association between neighbourhood-level SES and fruit consumption in Canada, New Zealand and Scotland, with increased odds of greater fruit intake in higher SES neighbourhoods. In Australia, Canada, New Zealand and Portugal, those residing in higher SES neighbourhoods had increased odds of greater vegetable intake. The other studies showed no evidence of a difference by neighbourhood-level SES. CONCLUSIONS: Acknowledging discrepancies across studies in terms of sampling, measures, and definitions of neighbourhoods, this opportunistic study, which treated data in a consistent manner, suggests that associations between diet and neighbourhood-level socioeconomic status vary across countries. Neighbourhood socioeconomic disadvantage may differentially impact on access to resources in which produce is available in different countries. Neighbourhood environments have the potential to influence behaviour and further research is required to examine the context in which these associations arise

Social relationships, neighbourhood poverty and cumulative biological risk: findings from a multi-racial US urban community.

Prior research has established associations between neighbourhood poverty and cumulative biological risk (CBR). CBR is conceptualized as indicative of the effects of stress on biological functioning, and is linked with increased morbidity and mortality. Studies suggest that supportive social relationships may be health protective, and may erode under conditions of poverty. This study examines whether social relationships are inversely associated with CBR and whether associations between neighbourhood poverty and CBR are mediated through social relationships. Data were from a stratified probability sample community survey (n=919) of residents of Detroit, Michigan, USA (2002-2003) and from the 2000 US Census. The outcome variable, CBR, included anthropometric and clinical measures. Independent variables included four indicators of social relationships: social support, neighbourhood satisfaction, social cohesion and neighbourhood participation. Multilevel models were used to test both research questions, with neighbourhood poverty and social relationships included at the block group level, and social relationships also included at the individual level, to disentangle individual from neighbourhood effects. Findings suggest some associations between social relationships and CBR after accounting for neighbourhood poverty and individual characteristics. In models that accounted for all indicators of social relationships, individual-level social support was associated with greater CBR (β=0.12, p=0.04), while neighbourhood-level social support was marginally significantly protective of CBR (within-neighbourhood: β=-0.36, p=0.06; between-neighbourhood: β=-0.24, p=0.06). In contrast, individual-level neighbourhood satisfaction was protective of CBR (β=-0.10, p=0.02), with no within-neighbourhood (β=0.06, p=0.54) or between-neighbourhood association (β=-0.04, p=0.38). Results indicate no significant association between either social cohesion or neighbourhood participation and CBR. Associations between neighbourhood poverty and CBR were not mediated by social relationships. These findings suggest that neighbourhood-level social support and individual-level neighbourhood satisfaction may be health protective and that neighbourhood poverty, social support and neighbourhood satisfaction are associated with CBR through independent pathways

Does Perceived Safety Modify the Effectiveness of a Walking-Group Intervention Designed to Promote Physical Activity?

PURPOSE: To examine whether perceived safety modified the effectiveness of the Walk Your Heart to Health (WYHH) intervention in promoting physical activity and reducing central adiposity in predominantly non-Latino black (henceforth black) and Latino communities. DESIGN: Generalized estimation equations were used to assess modifying effects of perceived safety on the route and perceived neighborhood safety on (1) WYHH participation at 8 weeks and 32 weeks, (2) associations between participation and physical activity, and (3) associations between physical activity and central adiposity. SETTING: Community-based and faith-based organizations in black and Latino communities. PARTICIPANTS: There were 603 adults, aged 18 years and older, who were predominantly black, Latino, and female. MEASURES: Participation and physical activity (piezoelectric pedometer) were measured at each walking session. Perceived safety on the route (questionnaire), perceived neighborhood safety (questionnaire), and waist circumference were measured at baseline, 8 weeks, and 32 weeks. ANALYSIS: Secondary analysis of repeated measures using generalized estimation equations. RESULTS: Retention was 90% at 8 weeks and 64% at 32 weeks. Perceived safety on the route, but not perceived neighborhood safety, dampened participation at 8 weeks but not 32 weeks. Consistent participation in the intervention increased physical activity and reduced central adiposity irrespective of perceived safety on the walking route or perceived neighborhood safety. CONCLUSION: Efforts to improve safety in conjunction with interventions focused on increasing physical activity can work toward improving physical activity for blacks and Latinos, leading to a myriad of improved health outcomes including reduced central adiposity

Independent and Joint Contributions of Fine Particulate Matter Exposure and Population Vulnerability to Mortality in the Detroit Metropolitan Area

Fine particulate matter is associated with adverse health outcomes. Exposure to fine particulate matter may disproportionately affect urban communities with larger numbers of vulnerable residents. We used multilevel logistic regression models to estimate the joint effects of fine particulate matter (PM2.5) and population vulnerabilities on cardiopulmonary mortality (CPM). We estimated the health benefits of reductions in PM2.5 across census tracts in the Detroit metropolitan area with varying levels of population vulnerability, using cluster-specific odds ratios scaled to reflect PM2.5-attributable cardiopulmonary risk. PM2.5 and population vulnerability were independently associated with odds of CPM. Odds of CPM and the number of deaths attributable to PM2.5 were greatest in census tracts with both high PM2.5 exposures and population vulnerability. Reducing PM2.5 in census tracts with high PM2.5 would lead to an estimated 18% annual reduction in PM2.5-attributable CPM. Between 78–79% of those reductions in CPM would occur within census tracts with high population vulnerabilities. These health benefits of reductions in PM2.5 occurred at levels below current U.S. reference concentrations. Focusing efforts to reduce PM2.5 in the Detroit metropolitan area in census tracts with currently high levels would also lead to greater benefits for residents of census tracts with high population vulnerabilities