Katherine King

Cognitive function in the community setting: the neighbourhood as a source of ‘cognitive reserve’?

Background Existing research has found a positive association between cognitive function and residence in a socioeconomically advantaged neighbourhood. Yet, the mechanisms underlying this relationship have not been empirically investigated. Objective To test the hypothesis that neighbourhood socioeconomic structure is related to cognitive function partly through the availability of neighbourhood physical and social resources (eg, recreational facilities, community centres and libraries), which promote cognitively beneficial activities such as exercise and social integration. Methods Using data from a representative survey of community-dwelling adults in the city of Chicago (N=949 adults aged 50 and over), cognitive function was assessed with a modified version of the Telephone Interview for Cognitive Status instrument. Neighbourhood socioeconomic structure was derived from US census indicators. Systematic social observation was used to directly document the presence of neighbourhood resources on the blocks surrounding each respondents residence. Results Using multilevel linear regression, residence in an affluent neighbourhood had a net positive effect on cognitive function after adjusting for individual risk factors. For white respondents, the effects of neighbourhood affluence operated in part through a greater density of institutional resources (eg, community centres) that promote cognitively beneficial activities such as physical activity. Stable residence in an elderly neighbourhood was associated with higher cognitive function (potentially due to greater opportunities for social interaction with peers), but long term exposure to such neighbourhoods was negatively related to cognition. Conclusions Neighbourhood resources have the potential to promote ‘cognitive reserve’ for adults who are ageing in place in an urban setting.

Epigenetic regulation of Newborns’ imprinted genes related to gestational growth: patterning by parental race/ethnicity and maternal socioeconomic status

Background Children born to parents with lower income and education are at risk for obesity and later-life risk of common chronic diseases, and epigenetics has been hypothesised to link these associations. However, epigenetic targets are unknown. We focus on a cluster of well-characterised genomically imprinted genes because their monoallelic expression is regulated by DNA methylation at differentially methylated regions (DMRs), are critical in fetal growth, and DNA methylation patterns at birth have been associated with increased risk of birth weight extremes and overweight status or obesity in early childhood. Methods We measured DNA methylation at DMRs regulating genomically imprinted domains (IGF2/H19, DLK1/MEG3, NNAT and PLAGL1) using umbilical cord blood leucocytes from 619 infants recruited in Durham, North Carolina in 2010–2011. We examined differences in DNA methylation levels by race/ethnicity of both parents, and the role that maternal socioeconomic status (SES) may play in the association between race/ethnic epigenetic differences. Results Unadjusted race/ethnic differences only were evident for DMRs regulating MEG3 and IGF2; race/ethnic differences persisted in IGF2/H19 and NNAT after accounting for income and education. Conclusions Results suggest that parental factors may not only influence DNA methylation, but also do so in ways that vary by DMR. Findings support the hypothesis that epigenetics may link the observed lower SES during the prenatal period and poor outcomes such as low birth weight; lower birth weight has previously been associated with adult-onset chronic diseases and conditions that include cardiovascular diseases, diabetes, obesity and some cancers.

A Disadvantaged Advantage in Walkability: Findings From Socioeconomic and Geographical Analysis of National Built Environment Data in the United States

Urban form-the structure of the built environment-can influence physical activity, yet little is known about how walkable design differs according to neighborhood sociodemographic composition. We studied how walkable urban form varies by neighborhood sociodemographic composition, region, and urbanicity across the United States. Using linear regression models and 2000-2001 US Census data, we investigated the relationship between 5 neighborhood census characteristics (income, education, racial/ethnic composition, age distribution, and sex) and 5 walkability indicators in almost 65,000 census tracts in 48 states and the District of Columbia. Data on the built environment were obtained from the RAND Corporations (Santa Monica, California) Center for Population Health and Health Disparities (median block length, street segment, and node density) and the US Geological Surveys National Land Cover Database (proportion open space and proportion highly developed). Disadvantaged neighborhoods and those with more educated residents were more walkable (i.e., shorter block length, greater street node density, more developed land use, and higher density of street segments). However, tracts with a higher proportion of children and older adults were less walkable (fewer street nodes and lower density of street segments), after adjustment for region and level of urbanicity. Research and policy on the walkability-health link should give nuanced attention to the gap between persons living in walkable areas and those for whom walkability has the most to offer.

Jane Jacobs and ‘The Need for Aged Buildings’: Neighbourhood Historical Development Pace and Community Social Relations

Jacobs argued that grand planning schemes intending to redevelop large swaths of a city according to a central theoretical framework fail because planners do not understand that healthy cities are organic, spontaneous, messy, complex systems that result from evolutionary processes. She argued that a gradual pace of redevelopment would facilitate maintenance of existing interpersonal ties. This paper operationalises the concept of pace of development within a cross-sectional framework as the ‘age diversity of housing’. Analysis of a population-based multilevel community survey of Chicago linked with census housing data predicts individual perceptions of neighbourhood social relations (cohesion, control, intergenerational closure and reciprocal exchange). A gradual pace of redevelopment resulting in historical diversity of housing significantly predicts social relations, lending support to Jacobs’s claims.

Negative Life Events Vary by Neighborhood and Mediate the Relation between Neighborhood Context and Psychological Well-Being

Researchers have speculated that negative life events are more common in troubled neighborhoods, amplifying adverse effects on health. Using a clustered representative sample of Chicago residents (2001–03; n = 3,105) from the Chicago Community Adult Health Survey, we provide the first documentation that negative life events are highly geographically clustered compared to health outcomes. Associations between neighborhood context and negative life events were also found to vary by event type. We then demonstrate the power of a contextualized approach by testing path models in which life events mediate the relation between neighborhood characteristics and health outcomes, including self-rated health, anxiety, and depression. The indirect paths between neighborhood conditions and health through negative life event exposure are highly significant and large compared to the direct paths from neighborhood conditions to health. Our results indicate that neighborhood conditions can have acute as well as chronic effects on health, and that negative life events are a powerful mechanism by which context may influence health.

Neighborhood Walkable Urban Form and C-Reactive Protein

BACKGROUND Walkable urban form predicts physical activity and lower body mass index, which lower C-reactive protein (CRP). However, urban form is also related to pollution, noise, social and health behavior, crowding, and other stressors, which may complement or contravene walkability effects. PURPOSE This paper assesses within-neighborhood correlation of CRP, and whether three features of walkable urban form (residential density, street connectivity, and land use mix) are associated with CRP levels. METHODS CRP measures (n=610) and sociodemographic data come from the 2001-3 Chicago Community Adult Health Study, linked with objective built environment data. RESULTS Within-neighborhood correlations of CRP are greater than those of related health measures. A one standard deviation increase in residential density predicts significantly higher log CRP (e.g. β=0.11, p<.01) in Chicago, while a one standard deviation increase in land use mix predicts significantly lower CRP (e.g. β=-0. 19, p<0.01). Street connectivity is unrelated to CRP in this highly walkable city. DISCUSSION Results suggest that residential density may be a risk factor for inflammation, while greater walkability of mixed land use areas may be protective. It may be that negative aspects of density overcome the inflammatory benefits of walking.

The Association of Health and Income in the Elderly: Experience from a Southern State of Brazil

Objectives In high income, developed countries, health status tends to improve as income increases, but primarily through the 50th-66th percentile of income. It is unclear whether the same limitation holds in middle income countries, and for both general assessments of health and specific conditions. Methods Data were obtained from Brazil, a middle income country. In-person interviews with a representative sample of community residents age ≥60 (N=6963), in the southern state of Rio Grande do Sul, obtained information on demographic characteristics including household income and number of persons supported, general health status (self-rated health, functional status), depression, and seven physician-diagnosed, self-reported health conditions. Analyses used household income (adjusted for number supported and economies of scale) together with higher order income terms, and controlled for demographics and comorbidities, to ascertain nonlinearity between income and general and specific health measures. Results In fully controlled analyses income was associated with general measures of health (linearly with self-rated health, nonlinearly with functional status). For specific health measures there was a consistent linear association with depression, pulmonary disorders, renal disorders, and sensory impairment. For musculoskeletal, cardiovascular (negative association), and gastrointestinal disorders this association no longer held when comorbidities were controlled. There was no association with diabetes. Conclusion Contrary to findings in high income countries, the association of household-size-adjusted income with health was generally linear, sometimes negative, and sometimes absent when comorbidities were controlled.

Aggravating conditions: Cynical hostility and neighborhood ambient stressors

This study is the first to investigate neighborhood clustering of a personality trait--cynical hostility (a sense of mistrust of others amplified by suspicious antagonism.) Cynical hostility increases physiological reactivity by influencing appraisal and coping when stressful events occur and that has been well established as a predictor of cardiovascular disease, inflammation, and all-cause mortality. The analysis examines the associations of a variety of neighborhood physical and social conditions (especially ambient stressors) with individual cynical hostility, controlling for individual sociodemographics. Data are from the Chicago Community Adult Health Survey, a clustered population-based study of 3105 adults. Variation by neighborhood in cynical hostility is larger than variation of other selected health outcomes, which are commonly studied using ecological methods or for other personality measures. Controlling for neighborhood context reduces the black/white cynical hostility disparity by one-third. A measure of neighborhood ambient stressors (notably noise) significantly predicts cynical hostility, even after individual characteristics are controlled, and the effect size is larger than for other contextual predictors. Health-related psychosocial and personality traits may both cluster in and be influenced by contemporaneous neighborhoods rather than mere exogenous results of genes or early life conditions. Health-relevant psychosocial characteristics may also mediate effects of neighborhood deleterious physical conditions, thereby influencing downstream health outcomes and social disparities therein. Because residential location and neighborhood physical conditions are both modifiable, research on how ambient stressors influence health psychology may be particularly fruitful for health policy and practice.

Interpersonal discrimination and depressive symptomatology: Examination of several personality-related characteristics as potential confounders in a racial/ethnic heterogeneous adult sample

BackgroundResearch suggests that reports of interpersonal discrimination result in poor mental health. Because personality characteristics may either confound or mediate the link between these reports and mental health, there is a need to disentangle its role in order to better understand the nature of discrimination-mental health association. We examined whether hostility, anger repression and expression, pessimism, optimism, and self-esteem served as confounders in the association between perceived interpersonal discrimination and CESD-based depressive symptoms in a race/ethnic heterogeneous probability-based sample of community-dwelling adults.MethodsWe employed a series of ordinary least squares regression analyses to examine the potential confounding effect of hostility, anger repression and expression, pessimism, optimism, and self-esteem between interpersonal discrimination and depressive symptoms.ResultsHostility, anger repression, pessimism and self-esteem were significant as possible confounders of the relationship between interpersonal discrimination and depressive symptoms, together accounting for approximately 38% of the total association (beta: 0.1892, p < 0.001). However, interpersonal discrimination remained a positive predictor of depressive symptoms (beta: 0.1176, p < 0.001).ConclusionAs one of the first empirical attempts to examine the potential confounding role of personality characteristics in the association between reports of interpersonal discrimination and mental health, our results suggest that personality-related characteristics may serve as potential confounders. Nevertheless, our results also suggest that, net of these characteristics, reports of interpersonal discrimination are associated with poor mental health.

A Cumulative Deficit Laboratory Test–based Frailty Index: Personal and Neighborhood Associations

To explore the association between a newly developed cumulative laboratory‐based frailty index (FI) and intrinsic (personal) and extrinsic (social, environmental) characteristics.