The Science of Precision Prevention: Research Opportunities and Clinical Applications to Reduce Cardiovascular Health Disparities

Precision prevention embraces personalized prevention but includes broader factors such as social determinants of health to improve cardiovascular health. The quality, quantity, precision, and diversity of data relatable to individuals and communities continue to expand. New analytical methods can be applied to these data to create tools to attribute risk, which may allow a better understanding of cardiovascular health disparities. Interventions using these analytic tools should be evaluated to establish feasibility and efficacy for addressing cardiovascular disease disparities in diverse individuals and communities. Training in these approaches is important to create the next generation of scientists and practitioners in precision prevention. This state-of-the-art review is based on a workshop convened to identify current gaps in knowledge and methods used in precision prevention intervention research, discuss opportunities to expand trials of implementation science to close the health equity gaps, and expand the education and training of a diverse precision prevention workforce.

An epigenome-wide analysis of DNA methylation, racialized and economic inequities, and air pollution

Importance

DNA methylation (DNAm) provides a plausible mechanism by which adverse exposures become embodied and contribute to health inequities, due to its role in genome regulation and responsiveness to social and biophysical exposures tied to societal context. However, scant epigenome-wide association studies (EWAS) have included structural and lifecourse measures of exposure, especially in relation to structural discrimination.

Objective

Our study tests the hypothesis that DNAm is a mechanism by which racial discrimination, economic adversity, and air pollution become biologically embodied.

Design

A series of cross-sectional EWAS, conducted in My Body My Story (MBMS, biological specimens collected 2008-2010, DNAm assayed in 2021); and the Multi Ethnic Study of Atherosclerosis (MESA; biological specimens collected 2010-2012, DNAm assayed in 2012-2013); using new georeferenced social exposure data for both studies (generated in 2022).

Setting

MBMS was recruited from four community health centers in Boston; MESA was recruited from four field sites in: Baltimore, MD; Forsyth County, NC; New York City, NY; and St. Paul, MN.

Participants

Two population-based samples of US-born Black non-Hispanic (Black NH), white non-Hispanic (white NH), and Hispanic individuals (MBMS; n=224 Black NH and 69 white NH) and (MESA; n=229 Black NH, n=555 white NH and n=191 Hispanic).

Exposures

Eight social exposures encompassing racial discrimination, economic adversity, and air pollution.

Main outcome

Genome-wide changes in DNAm, as measured using the Illumina EPIC BeadChip (MBMS; using frozen blood spots) and Illumina 450k BeadChip (MESA; using purified monocytes). Our hypothesis was formulated after data collection.

Results

We observed the strongest associations with traffic-related air pollution (measured via black carbon and nitrogen oxides exposure), with evidence from both studies suggesting that air pollution exposure may induce epigenetic changes related to inflammatory processes. We also found suggestive associations of DNAm variation with measures of structural racial discrimination (e.g., for Black NH participants, born in a Jim Crow state; adult exposure to racialized economic residential segregation) situated in genes with plausible links to effects on health.

Conclusions and Relevance

Overall, this work suggests that DNAm is a biological mechanism through which structural racism and air pollution become embodied and may lead to health inequities.

Gender differences in the association of individual and contextual socioeconomic status with hypertension in 230 Latin American cities from the SALURBAL study: a multilevel analysis

BACKGROUND

Despite global interest in gender disparities and social determinants of hypertension, research in urban areas and regions with a high prevalence of hypertension, such as Latin America, is very limited. The objective of this study was to examine associations of individual- and area-level socioeconomic status with hypertension in adults living in 230 cities in eight Latin America countries.

METHODS

In this cross-sectional study, we used harmonized data from 109,184 adults (aged 18-97 years) from the SALURBAL (Salud Urbana en America Latina/Urban Health in Latin America) project. Hypertension was assessed by self-report. Individual-, sub-city- and city-level education were used as proxies of socioeconomic status. All models were stratified by gender.

RESULTS

Higher individual-level education was associated with lower odds of hypertension among women (university education or higher versus lower than primary: odds ratio [OR] = 0.67, 95% confidence interval [CI] = 0.61-0.74) but higher odds among men (OR = 1.65; 95%CI 1.47-1.86), although in men an inverse association emerged when measured blood pressure was used (OR = 0.86; 95%CI 0.76-0.97). For both genders, living in sub-city areas with higher educational achievement was associated with higher odds of hypertension (OR per standard deviation [SD] = 1.07, 95%CI = 1.02-1.12; OR = 1.11 per SD, 95%CI = 1.05-1.18, for women and men, respectively). The association of city-level education with hypertension varied across countries. In Peru, there was an inverse association (higher city level education was associated with lower odds of hypertension) in women and men, but in other countries no association was observed. In addition, the inverse association of individual-level education with hypertension became stronger (in women) or emerged (in men) as city or sub-city education increased.

CONCLUSION

The social patterning of hypertension differs by gender and by the level of analysis highlighting the importance of context- and gender-sensitive approaches and policies to reduce the prevalence of hypertension in Latin America.

Effects of an urban cable car intervention on physical activity: the TrUST natural experiment in Bogotá, Colombia

BACKGROUND

Cable cars are part of the transport system in several cities in Latin America, but no evaluations of their effects on physical activity are available. TransMiCable is the first cable car in Bogotá, Colombia, and the wider intervention includes renovated parks and playgrounds. We assessed the effects of TransMiCable and the wider intervention on physical activity.

METHODS

The Urban Transformations and Health natural experiment was a prospective quasi-experimental study conducted from Feb 1, 2018, to Dec 18, 2018 (baseline, pre-intervention) and from July 2, 2019, to March 15, 2020 (post-intervention follow-up) in the TransMiCable intervention area (Ciudad Bolívar settlement) and a control area without TransMiCable (San Cristóbal settlement). A multistage strategy was used to sample households in each area, with one adult (aged ≥18 years) per household invited to participate. Eligible participants had lived in the intervention or control areas for at least 2 years and were not planning to move within the next 2 years. Physical activity was assessed among participants in the intervention and control areas before and after the inauguration of TransMiCable in Ciudad Bolívar with the International Physical Activity Questionnaire (long form) and with wearable accelerometers. Complete cases (those with baseline and follow-up data) were included in analyses. Respondents were classed as being physically active if they met 2020 WHO guidelines (≥150 min per week of moderate activity, ≥75 min per week of vigorous activity, or equivalent combinations); and accelerometery data were classified with the Freedson cut-points for adults. Data were also gathered in zonal parks (area ≥10 000 m2) and neighbourhood parks (area <10 000 m2) in the intervention and control areas by direct observation with the System for Observing Play and Recreation in Communities, to assess levels of physical activity before and after the TransMiCable intervention. Multilevel regression models were used to assess changes in physical activity associated with the TransMiCable intervention.

FINDINGS

Physical activity questionnaires were completed by 2052 adult participants (1289 [62·8%] women and 763 [37·2%] men; mean age 43·5 years [SD 17·7]) before the inauguration of TransMiCable. After the inauguration, the follow-up (final) questionnaire sample comprised 825 adults in the intervention group and 854 in the control group, including 357 adults in the intervention group and 334 in the control group with valid accelerometery data. 334 (40·5%) of 825 participants in the intervention group reported levels of physical activity that met the 2020 WHO guidelines during walking for transport before the intervention, and 426 (51·6%) afterwards (change 11·1 percentage points [95% CI 6·4 to 15·9]). A similar change was observed in the control group (change 8·0 percentage points [3·4 to 12·5]; adjusted odds ratio [OR] for the time-by-group interaction, intervention vs control group: 1·1 [95% CI 0·8 to 1·5], p=0·38). Time spent doing moderate-to-vigorous physical activity, measured with accelerometers, did not change in the intervention group after the inauguration of TransMiCable (change -0·8 min per day [-4·6 to 3·0]) and did not change compared with the control group (adjusted β for the time-by-group interaction: 1·4 min per day [95% CI -2·0 to 4·9], p=0·41). Moderate-to-vigorous physical activity was 52·1 min per day (SD 24·7) before and 59·4 min per day (35·2) after the inauguration of TransMiCable in new regular users who reported using TransMiCable during mandatory trips for work or education (n=32; change 7·3 min per day [-22·5 to 7·9]). After the intervention, an increase in the proportion of male individuals engaging in moderate or vigorous physical activity was observed in a renovated zonal park (adjusted OR for the time-by-group interaction, intervention vs control park: 2·7 [1·1 to 6·8], p=0·033). Female users of a renovated neighbourhood park were less likely to become engaged in moderate or vigorous physical activity than female users of the control area neighbourhood park (adjusted OR for the time-by-group interaction: 0·4 [0·1 to 0·6], p=0·019).

INTERPRETATION

It is encouraging that walking for transport remained high in the TransMiCable intervention area when the use of private motorised transport had increased elsewhere in Bogotá. In low-income urban areas, where transport-related walking is a necessity, transport interventions should be focused on efforts to maintain participation in active travel while improving conditions under which it occurs.

FUNDING

Wellcome Trust (as part of the Urban Health in Latin America project); Bogotá Urban Planning Department; Ministry of Science, Technology, and Innovation of Colombia; Universidad de Los Andes; Fundación Santa Fe de Bogotá; and Universidad del Norte.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Variation in youth and young adult homicide rates and their association with city characteristics in Latin America: the SALURBAL study

BACKGROUND

Latin America and the Caribbean (LAC) is one of the most urbanized and violent regions worldwide. Homicides in youth (15-24 years old, yo) and young adults (25-39yo) are an especially pressing public health problem. Yet there is little research on how city characteristics relate to homicide rates in youth and young adults. We aimed to describe homicide rates among youth and young adults, as well as their association with socioeconomic and built environment factors across 315 cities in eight LAC countries.

METHODS

This is an ecological study. We estimated homicide rates in youth and young adults for the period 2010-2016. We investigated associations of homicide rates with sub-city education and GDP, Gini, density, landscape isolation, population and population growth using sex-stratified negative binomial models with city and sub-city level random intercepts, and country-level fixed effects.

FINDINGS

The mean sub-city homicide rate per 100,000 in persons aged 15-24 was 76.9 (SD = 95.9) in male and 6.7 (SD = 8.5) in female, and in persons aged 25-39 was 69.4 (SD = 68.9) in male and 6.0 (SD = 6.7) in female. Rates were higher in Brazil, Colombia, Mexico and El Salvador than in Argentina, Chile, Panama and Peru. There was significant variation in rates across cities and sub-cities, even after accounting for the country. In fully adjusted models, higher sub-city education scores and higher city GDP were associated with a lower homicide rate among male and female (rate ratios (RR) per SD higher value in male and female, respectively, 0.87 (CI 0.84-0.90) and 0.90 (CI 0.86-0.93) for education and 0.87 (CI 0.81-0.92) and 0.92 (CI 0.87-0.97) for GDP). A higher city Gini index was associated with higher homicide rates (RR 1.28 (CI 1.10-1.48) and 1.21 (CI 1.07-1.36) in male and female, respectively). Greater isolation da was also associated with higher homicide rates (RR 1.13 (CI 1.07-1.21) and 1.07 (CI 1.02-1.12) in male and female, respectively).

INTERPRETATION

City and sub-city factors are associated with homicide rates. Improvements to education, social conditions and inequality and physical integration of cities may contribute to the reduction of homicides in the region.

FUNDING

The Wellcome Trust [205177/Z/16/Z].

Commuter's personal exposure to air pollutants after the implementation of a cable car for public transport: Results of the natural experiment TrUST

Commuters in urban settlements are frequently exposed to high concentrations of air pollutants due to their proximity to mobile sources, making exposure to traffic-related air pollutants an important public health issue. Recent trends in urban transport towards zero- and low-tailpipe emission alternatives will likely result in decreased exposure to air pollutants. The TrUST (Urban transformations and health) study offers a unique opportunity to understand the impacts of a new cable car (TransMiCable) in underserved communities within Bogotá, Colombia. The aims of this study are to assess the personal exposure to fine particulate matter (PM_2.5), equivalent Black Carbon (eBC), and Carbon Monoxide (CO) in transport micro-environments and to estimate the inhaled dose per trip during mandatory multimodal trips before and after the implementation of the TransMiCable. We collected personal exposure data for Bus-Rapid-Transit (BRT) feeder buses, regular buses, informal transport, pedestrians, and TransMiCable. TransMiCable showed lower exposure concentration compared to BRT feeder and regular buses (PM_2.5: 23.6 vs. 87.0 μg m^-3 (P ≤ 0.001) and eBC: 5.2 vs. 28.2 μg m^-3 (P ≤ 0.001), respectively). The mean concentration of PM_2.5 and eBC inside the TransMiCable cabins were 62 % and 82 % lower than the mean concentrations in buses. Furthermore, using a Monte Carlo simulation model, we found that including the TransMiCable as a feeder is related to a 54.4 μg/trip reduction in PM_2.5 inhaled dose and 35.8 μg/trip in eBC per trip. Those changes represent a 27 % and 34 % reduction in an inhaled dose per trip, respectively. Our results show that PM_2.5, eBC, and CO inhaled dose for TransMiCable users is reduced due to lower exposure concentration inside its cabins and shorter travel time. The implementation of a cable car in Bogotá is likely to reduce air pollution exposure in transport micro-environments used by vulnerable populations living in semi-informal settlements.

Measures of Food Inadequacy and Cardiovascular Disease Risk in Black Individuals in the US From the Jackson Heart Study

Importance

Food insecurity disproportionately affects Black individuals in the US. Its association with coronary heart disease (CHD), heart failure (HF), and stroke is unclear.

Objective

To evaluate the associations of economic food insecurity and proximity with unhealthy food options with risk of incident CHD, HF, and stroke and the role of diet quality and stress.

Design, Setting, and Participants

This cohort study was a time-to-event analysis of 3024 Black adult participants in the Jackson Heart Study (JHS) without prevalent cardiovascular disease (CVD) at visit 1 (2000-2004). Data analysis was conducted from September 1, 2020, to November 30, 2021.

Exposures

Economic food insecurity, defined as receiving food stamps or self-reported not enough money for groceries, and high frequency of unfavorable food stores (>2.5 unfavorable food stores [fast food restaurants, convenience stores] within 1 mile).

Main Outcomes and Measures

The main outcomes were incident CVD including incident CHD, stroke, and HF with preserved ejection fraction and with reduced ejection fraction (HFrEF). During a median follow-up of 13.8 (IQR, 12.8-14.6) years, the associations of measures of food inadequacy with incident CVD (CHD, stroke, and HF) were assessed using multivariable Cox proportional hazards regression models.

Results

Among the 3024 study participants, the mean (SD) age was 54 (12) years, 1987 (66%) were women, 630 (21%) were economically food insecure, and 50% (by definition) had more than 2.5 unfavorable food stores within 1 mile. In analyses adjusted for cardiovascular risk and socioeconomic factors, economic food insecurity was associated with higher risk of incident CHD (hazard ratio [HR], 1.76; 95% CI, 1.06-2.91) and incident HFrEF (HR, 2.07; 95% CI, 1.16-3.70), but not stroke. These associations persisted after further adjustment for diet quality and perceived stress. In addition, economic food insecurity was associated with higher high-sensitivity C-reactive protein and renin concentrations. High frequency of unfavorable food stores was not associated with CHD, HF, or stroke.

Conclusions and Relevance

The findings of this cohort study suggest that economic food insecurity, but not proximity to unhealthy food options, was associated with risk of incident CHD and HFrEF independent of socioeconomic factors, traditional cardiovascular risk factors, diet quality, perceived stress, and other health behaviors. Economic food insecurity was also associated with markers of inflammation and neurohormonal activation. Economic food insecurity may be a promising potential target for the prevention of CVD.

Modification of temperature-related human mortality by area-level socioeconomic and demographic characteristics in Latin American cities

BACKGROUND

In Latin America, where climate change and rapid urbanization converge, non-optimal ambient temperatures contribute to excess mortality. However, little is known about area-level characteristics that confer vulnerability to temperature-related mortality.

OBJECTIVES

Explore city-level socioeconomic and demographic characteristics associated with temperature-related mortality in Latin American cities.

METHODS

The dependent variables quantify city-specific associations between temperature and mortality: heat- and cold-related excess death fractions (EDF, or percentages of total deaths attributed to cold/hot temperatures), and the relative mortality risk (RR) associated with 1 °C difference in temperature in 325 cities during 2002-2015. Random effects meta-regressions were used to investigate whether EDFs and RRs associated with heat and cold varied by city-level characteristics, including population size, population density, built-up area, age-standardized mortality rate, poverty, living conditions, educational attainment, income inequality, and residential segregation by education level.

RESULTS

We find limited effect modification of cold-related mortality by city-level demographic and socioeconomic characteristics and several unexpected associations for heat-related mortality. For example, cities in the highest compared to the lowest tertile of income inequality have all-age cold-related excess mortality that is, on average, 3.45 percentage points higher (95% CI: 0.33, 6.56). Higher poverty and higher segregation were also associated with higher cold EDF among those 65 and older. Large, densely populated cities, and cities with high levels of poverty and income inequality experience smaller heat EDFs compared to smaller and less densely populated cities, and cities with little poverty and income inequality.

DISCUSSION

Evidence of effect modification of cold-related mortality in Latin American cities was limited, and unexpected patterns of modification of heat-related mortality were observed. Socioeconomic deprivation may impact cold-related mortality, particularly among the elderly. The findings of higher levels of poverty and income inequality associated with lower heat-related mortality deserve further investigation given the increasing importance of urban adaptation to climate change.

Comparing effects of Euclidean buffers and network buffers on associations between built environment and transport walking: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Transport walking has drawn growing interest due to its potential to increase levels of physical activities and reduce reliance on vehicles. While existing studies have compared built environment-health associations between Euclidean buffers and network buffers, no studies have systematically quantified the extent of bias in health effect estimates when exposures are measured in different buffers. Further, prior studies have done the comparisons focusing on only one or two geographic regions, limiting generalizability and restricting ability to test whether direction or magnitude of bias are different by context. This study aimed to quantify the degree of bias in associations between built environment exposures and transport walking when exposures were operationalized using Euclidean buffers rather than network buffers in diverse contexts.

METHODS

We performed a simulations study to systematically evaluate the degree of bias in associations between built environment exposures in Euclidean buffers and network buffers and transport walking, assuming network buffers more accurately captured true exposures. Additionally, we used empirical data from a multi-ethnic, multi-site cohort to compare associations between built environment amenities and walking for transport where built environment exposures were derived using Euclidean buffers versus network buffers.

RESULTS

Simulation results found that the bias induced by using Euclidean buffer models was consistently negative across the six study sites (ranging from -80% to -20%), suggesting built environment exposures measured using Euclidean buffers underestimate health effects on transport walking. Percent bias was uniformly smaller for the larger 5 km scale than the 1 km and 0.25 km spatial scales, independent of site or built environment categories. Empirical findings aligned with the simulation results: built environment-health associations were stronger for built environment exposures operationalized using network buffers than using Euclidean buffers.

CONCLUSION

This study is the first to quantify the extent of bias in the magnitude of the associations between built environment exposures and transport walking when the former are measured in Euclidean buffers vs. network buffers, informing future research to carefully conceptualize appropriate distance-based buffer metrics in order to better approximate real geographic contexts. It also helps contextualize existing research in the field that used Euclidean buffers when that were the only option. Further, this study provides an example of the uncertain geographic context problem.

Racial and Ethnic Differences in All-Cause and Cardiovascular Disease Mortality: The MESA Study

BACKGROUND

Despite improvements in population health, marked racial and ethnic disparities in longevity and cardiovascular disease (CVD) mortality persist. This study aimed to describe risks for all-cause and CVD mortality by race and ethnicity, before and after accounting for socioeconomic status (SES) and other factors, in the MESA study (Multi-Ethnic Study of Atherosclerosis).

METHODS

MESA recruited 6814 US adults, 45 to 84 years of age, free of clinical CVD at baseline, including Black, White, Hispanic, and Chinese individuals (2000-2002). Using Cox proportional hazards modeling with time-updated covariates, we evaluated the association of self-reported race and ethnicity with all-cause and adjudicated CVD mortality, with progressive adjustments for age and sex, SES (neighborhood SES, income, education, and health insurance), lifestyle and psychosocial risk factors, clinical risk factors, and immigration history.

RESULTS

During a median of 15.8 years of follow-up, 22.8% of participants (n=1552) died, of which 5.3% (n=364) died of CVD. After adjusting for age and sex, Black participants had a 34% higher mortality hazard (hazard ratio [HR], 1.34 [95% CI, 1.19-1.51]), Chinese participants had a 21% lower mortality hazard (HR, 0.79 [95% CI, 0.66-0.95]), and there was no mortality difference in Hispanic participants (HR, 0.99 [95% CI, 0.86-1.14]) compared with White participants. After adjusting for SES, the mortality HR for Black participants compared with White participants was reduced (HR, 1.16 [95% CI, 1.01-1.34]) but still statistically significant. With adjustment for SES, the mortality hazards for Chinese and Hispanic participants also decreased in comparison with White participants. After further adjustment for additional risk factors and immigration history, Hispanic participants (HR, 0.77 [95% CI, 0.63-0.94]) had a lower mortality risk than White participants, and hazard ratios for Black participants (HR, 1.08 [95% CI, 0.92-1.26]) and Chinese participants (HR, 0.81 [95% CI, 0.60-1.08]) were not significantly different from those of White participants. Similar trends were seen for CVD mortality, although the age- and sex-adjusted HR for CVD mortality for Black participants compared with White participants was greater than all-cause mortality (HR, 1.72 [95% CI, 1.34-2.21] compared with HR, 1.34 [95% CI, 1.19-1.51]).

CONCLUSIONS

These results highlight persistent racial and ethnic differences in overall and CVD mortality, largely attributable to social determinants of health, and support the need to identify and act on systemic factors that shape differences in health across racial and ethnic groups.

Educational inequalities, urbanicity and levels of non-communicable diseases risk factors: evaluating trends in Argentina (2005-2013)

BACKGROUND

We investigated a) whether urbanicity is associated with individual-level non-communicable diseases (NCD) risk factors and whether urbanicity modifies trends over time in risk factors; and (b) whether educational inequalities in NCD risk factors change over time or are modified by province urbanicity.

METHODS

We used data from three large national surveys on NCD risk factors (Encuesta Nacional de Factores de Riesgo; ENFR2005-2009-2013) conducted in urban areas of Argentina (n = 108,489). We used gender-stratified logistic random-intercept models (individuals nested within provinces) to determine adjusted associations of self-reported individual NCD risk factors (hypertension, diabetes, obesity, and current smoking) with education and urbanicity.

RESULTS

In both men and women, the prevalence of obesity and diabetes increased over time but smoking decreased. Hypertension prevalence increased over time in men. Higher urbanicity was associated with higher odds of smoking and lower odds of hypertension in women but was not associated with NCD risk factors in men. Obesity increased more over time in more compared to less urbanized provinces (in men) while smoking decreased more over time in less urbanized provinces. All risk factors had a higher prevalence in persons with lower education (stronger in women than in men), except for diabetes in men and smoking in women. Educational inequalities in obesity (in men) and hypertension (in men and women) became stronger over time, while an initial inverse social gradient in smoking for women reverted and became similar to other risk factors over time. In general, the inverse associations of education with the risk factors became stronger with increasing levels of province urbanicity.

CONCLUSION

Increasing prevalence of diabetes and obesity over time and growing inequities by education highlight the need for policies aimed at reducing NCD risk factors among lower socioeconomic populations in urban environments in Argentina.

Climate Trends and Consumption of Foods and Beverages by Processing Level in Mexican Cities

Background: Little is known about the potential impact of climate change on food systems and diet. We aimed to estimate the association of changes in rainfall and temperatures with consumption of unprocessed and processed foods among residents of Mexican cities by climate region.

Methods: We analyzed 3,312 participants of the 2012 Mexican National Health and Nutrition Survey with dietary intake and sociodemographic information linked to historical rainfall and temperature data collected by the Mexican National Weather Service. We classified foods as unprocessed, processed, or ultra-processed. We performed multilevel linear regression to estimate the association of annual change in rainfalls (for each 0.5 mm decrease) and temperatures (for each 0.1°C increase) at municipality level over the past 5 years with consumption of processed and unprocessed foods measured as the contribution to total energy intake. We investigated whether associations differed by climate region (tropical, temperate, and arid).

Results: Each 0.5 mm annual decrease in precipitation was associated with lower consumption of unprocessed foods and higher consumption of ultra-processed foods [mean differences in percent contribution to total energy intake −0.009% (95% CI: −0.019, < −0.001) and 0.011% (95% CI: 0.001, 0.021), respectively]. Each 0.1 degree Celsius annual increase in temperature was also associated with lower consumption of unprocessed and higher consumption of ultra-processed foods [mean differences in percent contribution to total energy intake was −0.03 (95% CI: −0.05, −0.01) and 0.03% (95% CI: <0.01, 0.05)]. When stratified by climate region these associations were only observed in tropical regions.

Conclusions: Decreases in rainfalls and increases in temperature were associated with lower consumption of unprocessed foods but higher consumption of ultra-processed foods, especially in tropical regions. Previous studies have established how food production affects the climate, our study suggests that climate change could, in turn, reinforce modern food production, closing a vicious circle with clear negative implications for planetary health.

Ambient fine particulate matter in Latin American cities: Levels, population exposure, and associated urban factors

BACKGROUND

Exposure to particulate matter (PM_2.5) is a major risk factor for morbidity and mortality. Yet few studies have examined patterns of population exposure and investigated the predictors of PM_2.5 across the rapidly growing cities in lower- and middle-income countries.

OBJECTIVES

Characterize PM_2.5 levels, describe patterns of population exposure, and investigate urban factors as predictors of PM_2.5 levels.

METHODS

We used data from the Salud Urbana en America Latina/Urban Health in Latin America (SALURBAL) study, a multi-country assessment of the determinants of urban health in Latin America, to characterize PM_2.5 levels in 366 cities comprising over 100,000 residents using satellite-derived estimates. Factors related to urban form and transportation were explored.

RESULTS

We found that about 172 million or 58% of the population studied lived in areas with air pollution levels above the defined WHO-AQG of 10 μg/m³ annual average. We also found that larger cities, cities with higher GDP, higher motorization rate and higher congestion tended to have higher PM_2.5. In contrast cities with higher population density had lower levels of PM_2.5. In addition, at the sub-city level, higher intersection density was associated with higher PM_2.5 and more green space was associated with lower PM_2.5. When all exposures were examined adjusted for each other, higher city per capita GDP and higher sub-city intersection density remained associated with higher PM_2.5 levels, while higher city population density remained associated with lower levels. The presence of mass transit was also associated with lower PM_2.5 after adjustment. The motorization rate also remained associated with PM_2.5 and its inclusion attenuated the effect of population density.

DISCUSSION

These results show that PM_2.5 exposures remain a major health risk in Latin American cities and suggest that urban planning and transportation policies could have a major impact on ambient levels.

Urban social environment and low birth weight in 360 Latin American cities

OBJECTIVE

Using data compiled by the SALURBAL project (Urban Health in Latin America; 'Salud Urbana en América Latina') we quantified variability in low birth weight (LBW) across cities in Latin America, and evaluated the associations of socio-economic characteristics at various levels (maternal, sub-city and city) with the prevalence of LBW.

METHODS

The sample included 8 countries, 360 cities, 1321 administrative areas within cities (sub-city units) and birth registers of more than 4.5 million births for the year 2014. We linked maternal education from birth registers to data on socioeconomic characteristics of sub-cities and cities using the closest available national population census in each country. We applied linear and Poisson random-intercept multilevel models for aggregated data.

RESULTS

The median prevalence of city LBW by country ranged from a high of 13% in Guatemala to a low of 5% in Peru (median across all cities was 7.8%). Most of the LBW variability across sub-cities was between countries, but there were also significant proportions between cities within a country, and within cities. Low maternal education was associated with higher prevalence of LBW (Prevalence rate ratios (PRR) for less than primary vs. completed secondary or more 1.12 95% CI 1.10, 1.13) in the fully adjusted model. In contrast, higher sub-city education and a better city social environment index were independently associated with higher LBW prevalence after adjustment for maternal education and age, city population size and city gross domestic product (PRR 1.04 95% CI 1.03, 1.04 per SD higher sub-city education and PRR 1.02 95% CI 1.00, 1.04 per SD higher SEI). Larger city size was associated with a higher prevalence of LBW (PRR 1.06; 95% CI 1.01, 1.12).

CONCLUSION

Our findings highlight the presence of heterogeneity in the distribution of LBW and the importance of maternal education, local and broader social environments in shaping LBW in urban settings of Latin America. Implementing context-sensitive interventions guided to improve women's education is recommended to tackle LBW in the region.

Primary Care Accessibility Effects on Health Care Utilization Among Urban Children

OBJECTIVE

Evidence suggests that spatial accessibility to primary care is a contributing factor to appropriate health care utilization, with limited primary care access resulting in avoidable hospitalizations and emergency department visits which are burdensome on individuals and our health care system. Limited research, however, has examined the effects on children.

METHODS

We evaluated associations of spatial accessibility to primary care on health care utilization among a sample of 16,709 children aged 0 to 3 years in Philadelphia who were primarily non-White and publicly insured. Log-Poisson models with generalized estimating equations were used to estimate incidence rate ratios (RR) and 95% confidence intervals (CI), while accounting for 3 levels of clustering (within individual, within primary care practice, within neighborhood).

RESULTS

In age-adjusted models, the lowest level of spatial accessibility was associated with 7% fewer primary care visits (RR 0.93, 95% CI 0.91, 0.95), 15% more emergency department visits (RR 1.15, 95% CI 1.09, 1.22), and 18% more avoidable hospitalizations (RR 1.18, 95% CI 1.01, 1.37). After adjustment for individual- (race/ethnicity, sex, number of chronic conditions, insurance status) and neighborhood-level (racial composition and proportion of housing units with no vehicle), spatial accessibility was not significantly associated with rate of health care utilization.

CONCLUSIONS

Individual-level predisposing factors, such as age, race, and need, attenuate the association between accessibility to primary care and use of primary care, emergency department visits, and avoidable hospitalization. Given the possibility of modifying access to primary care unlike immutable individual factors, a focus on spatial accessibility to primary care may promote appropriate health care utilization.

Sex and ethnicity modify the associations between individual and contextual socioeconomic indicators and ideal cardiovascular health: MESA study

BACKGROUND

Low socioeconomic status (SES) is associated with cardiovascular disease (CVD) risk, but its association with different markers of SES may be heterogeneous by sex and race/ethnicity.

METHODS

We have examined the relationships of four SES markers (education, family income, occupation and neighborhood SES) to ideal cardiovascular health (ICH), an index formed by seven variables. A total of 6792 cohort participants from six regions in the USA: Baltimore City and Baltimore County, MD; Chicago, IL; Forsyth County, NC; Los Angeles County, CA; New York, NY; and St. Paul, MN of the Multi-Ethnic Study of Atherosclerosis (MESA) (52.8% women) were recruited at baseline (2000-2) and included in the present analysis.

RESULTS

ICH was classified as poor, intermediate or ideal. Level of education was significantly and inversely associated with ICH in non-Hispanic White men and women, in Chinese-American and Hispanic American men and African-American women. Family income was inversely and significantly associated with poor ICH in African-American men only.

CONCLUSIONS

We conclude that the strength of the associations between some SES markers and ICH differ between sexes and race/ethnic groups.

Social regulation of inflammation related gene expression in the multi-ethnic study of atherosclerosis

BACKGROUND

Exposure to adverse social factors has been associated with an altered inflammatory profile, a risk factor for several acute and chronic diseases. Differential gene expression may be a biological mediator in the relationship. In this study, associations between a range of social factors and expression of inflammation-related genes were investigated.

METHODS

Social factor and gene expression data were collected from 1,264 individuals in the Multi-Ethnic Study of Atherosclerosis (MESA). Inflammation-related genes were identified from the Gene Ontology database. The associations between social factors and gene expression were first assessed using the Global Analysis of Covariance (Global ANCOVA) gene set enrichment test. When the global test was significant, linear regression and elastic net penalized regression were employed to identify the individual gene transcripts within each gene set associated with the social factor.

RESULTS

Loneliness (p = 0.003), chronic burden (p = 0.002), and major or lifetime discrimination (p = 0.045) were significantly associated with global expression of the chronic inflammatory gene set. Of the 20 transcripts that comprise this gene set, elastic net selected 12 transcripts for loneliness, 8 for chronic burden, and 3 for major or lifetime discrimination. Major or lifetime discrimination was also associated with the inflammatory response (p = 0.029), regulation of the inflammatory response (p = 0.041), and immune response (p = 0.025) gene sets in global analyses, and 53, 136, and 26 transcripts were selected via elastic net for these gene sets respectively. There were no significant associations in linear regression analyses after adjustment for multiple testing.

CONCLUSIONS

This study highlights gene expression as a biological mechanism through which social factors may affect inflammation.

Negative Affect and Risk of Atrial Fibrillation: MESA

Background

Current literature examining the prospective relationship between depression and other measures of negative affect with atrial fibrillation (AF) are limited. We determined the relationships of depression, anger, anxiety, and chronic stress with incident AF in a multiethnic cohort of middle‐ and older‐aged adults.

Methods and Results

This analysis included 6644 MESA (Multi‐Ethnic Study of Atherosclerosis) study participants who were free of AF at baseline. Depressive symptoms were assessed at baseline and defined as either a 20‐item Center for Epidemiologic Studies Depression Scale score ≥16 or use of antidepressant medications. The Spielberger Trait Anger Scale, Spielberger Trait Anxiety Scale, and Chronic Burden Scale were also administered at baseline to assess anger, anxiety, and chronic stress, respectively. The primary outcome was incident AF, identified by follow‐up study visit ECGs, hospital discharge diagnoses, or Medicare claims data. A total of 875 (13%) incident AF cases were detected over a median follow‐up of nearly 13 years. A Center for Epidemiologic Studies Depression Scale score ≥16 (referent, Center for Epidemiologic Studies Depression Scale score <2) and antidepressant use were associated with a 34% and 36% higher risk of AF, respectively, in separate adjusted Cox proportional hazards analyses (hazard ratio, 1.34; 95% CI 1.04–1.74 for Center for Epidemiologic Studies Depression Scale ≥16; hazard ratio, 1.36; 95% CI, 1.04–1.77 for antidepressant use). No significant associations were observed for anger, anxiety, or chronic stress with development of AF.

Conclusions

Depressive symptoms are associated with an increased risk of incident AF. Further study into whether improving depressive symptoms reduces AF incidence is important.

Life Course Socioeconomic Status and Hypertension in African American Adults: The Jackson Heart Study

BACKGROUND

Limited research has examined the association of life-course socioeconomic status (SES) with hypertension prevalence and incidence in a large cohort of African Americans.

METHODS

Among 4,761 participants from the Jackson Heart Study (JHS), we examined the association of SES indicators with prevalent and incident hypertension. We used multivariable Poisson regression to estimate prevalence ratios (PR, 95% confidence interval-CI) of baseline (2000-2004) hypertension by adult (education, income, occupation, wealth) and childhood (mother's education) SES. Cox proportional hazards regression was used to estimate hazard ratios (HR, 95% CI) of incident hypertension by adult and childhood SES (2005-2013; 7.21 median years of follow-up). We also examined the association of childhood-to-adult SES mobility (parent-to-adult education) with prevalent and incident hypertension. Model 1 adjusted for age and sex. Model 2 added waist circumference, behaviors (smoking, alcohol, physical activity, diet), and diabetes prevalence.

RESULTS

High (vs. low) adult SES measures were associated with a lower prevalence of hypertension, with the exception of having a college degree and upper-middle income (PR: 1.04, 95% CI: 1.01, 1.07; PR: 1.05, 95% CI: 1.01, 1.09, respectively). Higher childhood SES was associated with a lower prevalence and risk of hypertension (PR: 0.83, 95%: CI 0.75, 0.91; HR: 0.76, 95% CI: 0.65, 0.89, respectively). Upward mobility and consistent high SES (vs. consistent low SES) from childhood to adulthood was associated with a greater prevalence, but lower incidence of hypertension.

CONCLUSION

Efforts to prevent hypertension among African Americans should consider childhood and current SES status.

Inequalities in life expectancy in six large Latin American cities from the SALURBAL study: an ecological analysis

BACKGROUND

Latin America is one of the most unequal regions in the world, but evidence is lacking on the magnitude of health inequalities in urban areas of the region. Our objective was to examine inequalities in life expectancy in six large Latin American cities and its association with a measure of area-level socioeconomic status.

METHODS

In this ecological analysis, we used data from the Salud Urbana en America Latina (SALURBAL) study on six large cities in Latin America (Buenos Aires, Argentina; Belo Horizonte, Brazil; Santiago, Chile; San José, Costa Rica; Mexico City, Mexico; and Panama City, Panama), comprising 266 subcity units, for the period 2011-15 (expect for Panama city, which was for 2012-16). We calculated average life expectancy at birth by sex and subcity unit with life tables using age-specific mortality rates estimated from a Bayesian model, and calculated the difference between the ninth and first decile of life expectancy at birth (P90-P10 gap) across subcity units in cities. We also analysed the association between life expectancy at birth and socioeconomic status at the subcity-unit level, using education as a proxy for socioeconomic status, and whether any geographical patterns existed in cities between subcity units.

FINDINGS

We found large spatial differences in average life expectancy at birth in Latin American cities, with the largest P90-P10 gaps observed in Panama City (15·0 years for men and 14·7 years for women), Santiago (8·9 years for men and 17·7 years for women), and Mexico City (10·9 years for men and 9·4 years for women), and the narrowest in Buenos Aires (4·4 years for men and 5·8 years for women), Belo Horizonte (4·0 years for men and 6·5 years for women), and San José (3·9 years for men and 3·0 years for women). Higher area-level socioeconomic status was associated with higher life expectancy, especially in Santiago (change in life expectancy per P90-P10 change unit-level of educational attainment 8·0 years [95% CI 5·8-10·3] for men and 11·8 years [7·1-16·4] for women) and Panama City (7·3 years [2·6-12·1] for men and 9·0 years [2·4-15·5] for women). We saw an increase in life expectancy at birth from east to west in Panama City and from north to south in core Mexico City, and a core-periphery divide in Buenos Aires and Santiago. Whereas for San José the central part of the city had the lowest life expectancy and in Belo Horizonte the central part of the city had the highest life expectancy.

INTERPRETATION

Large spatial differences in life expectancy in Latin American cities and their association with social factors highlight the importance of area-based approaches and policies that address social inequalities in improving health in cities of the region.

FUNDING

Wellcome Trust.

Association Between Long-term Exposure to Ambient Air Pollution and Change in Quantitatively Assessed Emphysema and Lung Function

IMPORTANCE

While air pollutants at historical levels have been associated with cardiovascular and respiratory diseases, it is not known whether exposure to contemporary air pollutant concentrations is associated with progression of emphysema.

OBJECTIVE

To assess the longitudinal association of ambient ozone (O3), fine particulate matter (PM2.5), oxides of nitrogen (NOx), and black carbon exposure with change in percent emphysema assessed via computed tomographic (CT) imaging and lung function.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included participants from the Multi-Ethnic Study of Atherosclerosis (MESA) Air and Lung Studies conducted in 6 metropolitan regions of the United States, which included 6814 adults aged 45 to 84 years recruited between July 2000 and August 2002, and an additional 257 participants recruited from February 2005 to May 2007, with follow-up through November 2018.

EXPOSURES

Residence-specific air pollutant concentrations (O3, PM2.5, NOx, and black carbon) were estimated by validated spatiotemporal models incorporating cohort-specific monitoring, determined from 1999 through the end of follow-up.

MAIN OUTCOMES AND MEASURES

Percent emphysema, defined as the percent of lung pixels less than -950 Hounsfield units, was assessed up to 5 times per participant via cardiac CT scan (2000-2007) and equivalent regions on lung CT scans (2010-2018). Spirometry was performed up to 3 times per participant (2004-2018).

RESULTS

Among 7071 study participants (mean [range] age at recruitment, 60 [45-84] years; 3330 [47.1%] were men), 5780 were assigned outdoor residential air pollution concentrations in the year of their baseline examination and during the follow-up period and had at least 1 follow-up CT scan, and 2772 had at least 1 follow-up spirometric assessment, over a median of 10 years. Median percent emphysema was 3% at baseline and increased a mean of 0.58 percentage points per 10 years. Mean ambient concentrations of PM2.5 and NOx, but not O3, decreased substantially during follow-up. Ambient concentrations of O3, PM2.5, NOx, and black carbon at study baseline were significantly associated with greater increases in percent emphysema per 10 years (O3: 0.13 per 3 parts per billion [95% CI, 0.03-0.24]; PM2.5: 0.11 per 2 μg/m3 [95% CI, 0.03-0.19]; NOx: 0.06 per 10 parts per billion [95% CI, 0.01-0.12]; black carbon: 0.10 per 0.2 μg/m3 [95% CI, 0.01-0.18]). Ambient O3 and NOx concentrations, but not PM2.5 concentrations, during follow-up were also significantly associated with greater increases in percent emphysema. Ambient O3 concentrations, but not other pollutants, at baseline and during follow-up were significantly associated with a greater decline in forced expiratory volume in 1 second per 10 years (baseline: 13.41 mL per 3 parts per billion [95% CI, 0.7-26.1]; follow-up: 18.15 mL per 3 parts per billion [95% CI, 1.59-34.71]).

CONCLUSIONS AND RELEVANCE

In this cohort study conducted between 2000 and 2018 in 6 US metropolitan regions, long-term exposure to ambient air pollutants was significantly associated with increasing emphysema assessed quantitatively using CT imaging and lung function.

Obstructive sleep apnea, nighttime arousals, and leukocyte telomere length: the Multi-Ethnic Study of Atherosclerosis

STUDY OBJECTIVES

Sleep disturbances and sleep apnea are associated with increased vulnerability to age-related disease, altering molecular pathways affecting biological aging. Telomere length captures one component of biological aging. We evaluated whether objectively assessed sleep and sleep apnea relate to leukocyte telomere length (LTL) in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

Men and women aged 44-84 years (n = 672) from the MESA Stress and MESA Sleep studies underwent polysomnography and 7 day actigraphy (at Exam 5) and assessment of LTL (at baseline [Exam 1] and about 10 years later [Exam 5]).

RESULTS

General linear models adjusting for age, sex, race/ethnicity, BMI, physical activity, and smoking found that severe obstructive sleep apnea (OSA; apnea-hypopnea index > 30) was cross-sectionally associated with shorter LTL (p = 0.007). Modest associations of shorter LTL with less rapid eye movement sleep, more stage 1 sleep, wake after sleep onset >30 min, and long sleep duration were found, but these effects were diminished after adjusting for lifestyle and OSA. Exploratory analyses found that higher arousal index at Exam 5 was associated with greater LTL decline over the prior 10 years (p = 0.004).

CONCLUSIONS

OSA was associated with shorter LTL. Individuals with high-arousal frequency had greater leukocyte telomere attrition over the prior decade. These findings suggest that sleep apnea and sleep fragmentation are associated with accelerated biological aging.

Expression of socially sensitive genes: The multi-ethnic study of atherosclerosis

BACKGROUND

Gene expression may be an important biological mediator in associations between social factors and health. However, previous studies were limited by small sample sizes and use of differing cell types with heterogeneous expression patterns. We use a large population-based cohort with gene expression measured solely in monocytes to investigate associations between seven social factors and expression of genes previously found to be sensitive to social factors.

METHODS

We employ three methodological approaches: 1) omnibus test for the entire gene set (Global ANCOVA), 2) assessment of each association individually (linear regression), and 3) machine learning method that performs variable selection with correlated predictors (elastic net).

RESULTS

In global analyses, significant associations with the a priori defined socially sensitive gene set were detected for major or lifetime discrimination and chronic burden (p = 0.019 and p = 0.047, respectively). Marginally significant associations were detected for loneliness and adult socioeconomic status (p = 0.066, p = 0.093, respectively). No associations were significant in linear regression analyses after accounting for multiple testing. However, a small percentage of gene expressions (up to 11%) were associated with at least one social factor using elastic net.

CONCLUSION

The Global ANCOVA and elastic net findings suggest that a small percentage of genes may be "socially sensitive," (i.e. demonstrate differential expression by social factor), yet single gene approaches such as linear regression may be ill powered to capture this relationship. Future research should further investigate the biological mechanisms through which social factors act to influence gene expression and how systemic changes in gene expression affect overall health.

The Epidemiology of Coping in African American Adults in the Jackson Heart Study (JHS)

Differences in coping within the African American population are not well understood, yet these differences may be critical to reducing stress, improving health, and reducing racial health disparities. Using a descriptive, exploratory analysis of the Jackson Heart Study (N = 5301), we examine correlations between coping responses and associations between coping and demographic, socioeconomic, psychosocial, and neighborhood factors. Overall, coping responses were not strongly correlated and patterns of associations between covariates and coping responses were largely inconsistent. The results suggest that coping varies substantially within this African American population and is driven mainly by psychosocial factors such as spirituality and interpersonal support. Understanding these complex relationships may inform strategies by which to intervene in the stress process to mitigate the effects of stress on health and to identify vulnerable subgroups of African Americans that might need targeted interventions to reduce exposure to stressors and improve coping capacities.

Neighborhood Environments and Diabetes Risk and Control

PURPOSE OF REVIEW

The objective of this review is to highlight the evidence on the association between contextual characteristics of residential environments and type 2 diabetes, to provide an overview of the methodological challenges and to outline potential topics for future research in this field.

RECENT FINDINGS

The link between neighborhood socioeconomic status or deprivation and diabetes prevalence, incidence, and control is robust and has been replicated in numerous settings, including in experimental and quasi-experimental studies. The association between characteristics of the built environment that affect physical activity, other aspects of the built environment, and diabetes risk is robust. There is also evidence for an association between food environments and diabetes risk, but some conflicting results have emerged in this area. While the evidence base on the association of neighborhood socioeconomic status and built and physical environments and diabetes is large and robust, challenges remain related to confounding due to neighborhood selection. Moreover, we also outline five paths forward for future research on the role of neighborhood environments on diabetes.

Neighborhood-based physical activity differences: Evaluation of the effect of health promotion program

Introduction

The practice of physical activity is an important factor in the prevention of health problems. However, a small portion of the population is physically active. Recent reviews show that physical activity classes in community settings have the potential to increase population levels of physical activity and reduce health inequalities.

Objective

To evaluate the effect of the Academias da Cidade Program in Belo Horizonte on the practice of physical activity in leisure time (PALT) by non-users living near the program centers.

Methods

We conducted a home-based health survey in Belo Horizonte (2008–2009) with 1,581 adults who were non-users of the program and who lived within a 1,500-meter radius of one active program center (exposed group) and two nonoperational centers with sites reserved for their construction (unexposed group). We collected data on PALT levels (≥150 minutes/week), which was measured with the Physical Activity International Questionnaire and analyzed with binary logistic regression using the Generalized Estimating Equations method. The propensity score was used as an adjustment variable to control the potential confusion in the measures of effect of exposure studied.

Results

The overall prevalence of the PALT was 26.5% in the exposed group and 22.7% in the unexposed group. The exposed group was more likely to be active in leisure time (OR = 1.05; CI 95%: 1.01–1.10). When considering the interaction between exposed group and distance, individuals in the exposed group who lived less than 500 meters from the program center were more likely to be active in leisure time (OR = 1.18, CI 95%: 1.03–1.35) compared to their counterparts.

Conclusion

Promoting physical activity in the community can favorably affect PALT levels among residents, especially those living closest to intervention centers. We believe the Academias da Cidade Program is a promising strategy to facilitate the access to appropriate spaces for the practice of physical activity and contribute to increase the levels physical activity within populations.

Neighborhood social and physical environments and type 2 diabetes mellitus in African Americans: The Jackson Heart Study

Using data from Jackson Heart Study, we investigated the associations of neighborhood social and physical environments with prevalence and incidence of type 2 diabetes mellitus (T2DM) in African Americans (AA). Among non-diabetic participants at baseline (n=3670), 521 (14.2%) developed T2DM during a median follow-up of 7.3 years. Measures of neighborhood social environments, and food and physical activity resources were derived using survey-and GIS-based methods. Prevalence ratios (PR) and Hazard ratios (HR) were estimated using generalized estimating equations and Cox proportional hazards models. Higher neighborhood social cohesion was associated with a 22% lower incidence of T2DM while higher density of unfavorable food stores was associated with a 34% higher incidence of T2DM after adjusting for individual-level risk factors (HR=0.78 [95% CI:0.62, 0.99] and HR=1.34 [1.12, 1.60], respectively). In addition, neighborhood problems was also associated with prevalence of T2DM (PR=1.12 [1.03, 1.21]) independent of individual-level risk factors. Our findings suggest that efforts to strengthen community ties or to attract healthy food retail outlets might be important strategies to consider for prevention of T2DM in AA.

Neighborhood Disadvantage, Poor Social Conditions, and Cardiovascular Disease Incidence Among African American Adults in the Jackson Heart Study

OBJECTIVES

To examine the impact of neighborhood conditions resulting from racial residential segregation on cardiovascular disease (CVD) risk in a socioeconomically diverse African American sample.

METHODS

The study included 4096 African American women (n = 2652) and men (n = 1444) aged 21 to 93 years from the Jackson Heart Study (Jackson, Mississippi; 2000-2011). We assessed neighborhood disadvantage with a composite measure of 8 indicators from the 2000 US Census. We assessed neighborhood-level social conditions, including social cohesion, violence, and disorder, with self-reported, validated scales.

RESULTS

Among African American women, each standard deviation increase in neighborhood disadvantage was associated with a 25% increased risk of CVD after covariate adjustment (hazard ratio = 1.25; 95% confidence interval = 1.05, 1.49). Risk also increased as levels of neighborhood violence and physical disorder increased after covariate adjustment. We observed no statistically significant associations among African American men in adjusted models.

CONCLUSIONS

Worse neighborhood economic and social conditions may contribute to increased risk of CVD among African American women. Policies directly addressing these issues may alleviate the burden of CVD in this group.

Adults’ Daily Walking for Travel and Leisure: Interaction Between Attitude Toward Walking and the Neighborhood Environment

Purpose:

Studies on how the interaction of psychological and environmental characteristics influences walking are limited, and the results are inconsistent. Our aim is to examine how the attitude toward walking and neighborhood environments interacts to influence walking.

Design:

Cross-sectional phone and mail survey.

Setting:

Participants randomly sampled from 6 study sites including Los Angeles, Chicago, Baltimore, Minneapolis, Manhattan, and Bronx Counties in New York City, and Forsyth and Davidson Counties in North Carolina.

Participants:

The final sample consisted of 2621 persons from 2011 to 2012.

Measures:

Total minutes of walking for travel or leisure, attitude toward walking, and perceptions of the neighborhood environments were self-reported. Street Smart (SS) Walk Score (a measure of walkability derived from a variety of geographic data) was obtained for each residential location.

Analysis:

Linear regression models adjusting for age, gender, race/ethnicity, education, and income.

Results:

Attitude toward walking was positively associated with walking for both purposes. Walking for travel was significantly associated with SS Walk Score, whereas walking for leisure was not. The SS Walk Score and selected perceived environment characteristics were associated with walking in people with a very positive attitude toward walking but were not associated with walking in people with a less positive attitude.

Conclusion:

Attitudes toward walking and neighborhood environments interact to affect walking behavior.

Spatially Modelling the Association Between Access to Recreational Facilities and Exercise: The 'Multi-Ethnic Study of Atherosclerosis'

Numerous studies have investigated the relationship between the built environment and physical activity. However these studies assume that these relationships are invariant over space. In this study, we introduce a novel method to analyze the association between access to recreational facilities and exercise allowing for spatial heterogeneity. In addition, this association is studied before and after controlling for crime, a variable that could explain spatial heterogeneity of associations. We use data from the Chicago site of the Multi-Ethnic Study of Atherosclerosis of 781 adults aged 46 years and over. A spatially varying coefficient Tobit regression model is implemented in the Bayesian setting to allow for the association of interest to vary over space. The relationship is shown to vary over Chicago, being positive in the south but negative or null in the north. Controlling for crime weakens the association in the south with little change observed in northern Chicago. The results of this study indicate that spatial heterogeneity in associations of environmental factors with health may vary over space and deserve further exploration.

Applying Novel Methods for Assessing Individual- and Neighborhood-Level Social and Psychosocial Environment Interactions with Genetic Factors in the Prediction of Depressive Symptoms in the Multi-Ethnic Study of Atherosclerosis

Complex illnesses, like depression, are thought to arise from the interplay between psychosocial stressors and genetic predispositions. Approaches that take into account both personal and neighborhood factors and that consider gene regions as well as individual SNPs may be necessary to capture these interactions across race and ethnic groups. We used novel gene-region based analysis methods [Sequence Kernel Association Test (SKAT) and meta-analysis (MetaSKAT), gene-environment set association test (GESAT)], as well as traditional linear models to identify gene region and SNP × psychosocial factor interactions at the individual- and neighborhood-level, across multiple race/ethnicities. Multiple regions identified in SKAT analyses showed evidence of a significant gene-region association with averaged depressive symptom scores across race/ethnicity (MetaSKAT p values <0.001). One region × neighborhood-environment interaction was significantly associated with averaged depressive symptom score across race/ethnicity after multiple testing correction (chr 18:21454070-21494070, Fisher's combined p value = 0.001). The examination of gene regions jointly with environmental factors measured at multiple levels (individuals and their contexts) may shed light on the etiology of depressive illness across race/ethnicities.

Psychosocial Factors and Risk of Incident Heart Failure: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Heart failure (HF) is a major source of morbidity and mortality in the United States. Psychosocial factors have frequently been studied as risk factors for coronary heart disease but not for HF.

METHODS AND RESULTS

We examined the relationship between psychological status and incident HF among 6782 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA). Anger, anxiety, chronic stress, depressive symptoms, and hostility were measured using validated scales, and physician reviewers adjudicated incident HF events. Cox proportional hazards models were used to adjust for relevant demographic, behavioral, and physiological covariates. Interactions by age, race, sex, and self-reported health were examined in exploratory analyses. During a mean follow-up of 9.3 years, 242 participants developed incident HF. There was no association between psychosocial factors and HF hazard ratios (95% confidence interval) for the highest versus lowest quartile: anger=1.14 (0.81-1.60), anxiety=0.74 (0.51-1.07), chronic stress=1.25 (0.90-1.72), depressive symptoms=1.19 (0.76-1.85), and hostility=0.95 (0.62-1.42). In exploratory analysis, among the participants reporting fair/poor health at baseline, those reporting high versus low levels of anxiety, chronic stress, and depressive symptoms had 2-fold higher risk of incident HF, but there was no association for those with good/very good/excellent self-reported health.

CONCLUSIONS

Overall, these psychosocial factors were not significantly associated with incident HF. However, for participants reporting poor health at baseline, there was evidence that anxiety, chronic stress, and depressive symptoms were associated with increased risk of HF. Future research with greater statistical power is necessary to replicate these findings and seek explanations.

Ambient air pollution and racial/ethnic differences in carotid intima-media thickness in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

In the USA, ethnic disparities in atherosclerosis persist after accounting for known risk factors. Ambient air pollution is associated with increased levels of atherosclerosis and differs in the USA by race/ethnicity. We estimated the influence of ambient air pollution exposure to ethnic differences in common carotid intima-media thickness (IMT).

METHODS

We cross-sectionally studied 6347 Caucasian-American, African-American, Hispanic and Chinese adults across 6 US cities in 2000-2002. Annual ambient air pollution concentrations (fine particulate matter [PM2.5] and oxides of nitrogen [NOX]) were estimated at each participant's residence. IMT was assessed by ultrasound.

RESULTS

The mean IMT was 19.4 and 37.6 μm smaller for Hispanic women and men, 53.6 and 7.1 μm smaller for Chinese women and men, and 23.4 and 38.7 μm higher for African-American women and men compared with Caucasian-American women and men. After adjustment for PM2.5, the differences in IMT remained similar for Hispanic and African-American participants but was even more negative for Chinese participants (mean IMT difference of -58.4 μm for women and -15.7 μm for men) compared with Caucasian-American participants. The IMT difference in Chinese participants compared with Caucasian-American participants related to their higher PM2.5 exposures was 4.8 μm (95% CI 0.2 to 10.8) for women and 8.6 μm (95% CI 3.4 to 15.3) for men. NOX was not related to ethnic differences in IMT.

CONCLUSIONS

The smaller carotid IMT levels in Chinese participants were even smaller after accounting for higher PM2.5 concentrations in Chinese participants compared with Caucasian-American participants. Air pollution was not related to IMT differences in African-American and Hispanic participants compared with Caucasian-American participants.

Job Strain, Occupational Category, Systolic Blood Pressure, and Hypertension Prevalence: The Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To assess associations of occupational categories and job characteristics with prevalent hypertension.

METHODS

We analyzed 2517 Multi-Ethnic Study of Atherosclerosis participants, working 20+ hours per week, in 2002 to 2004.

RESULTS

Higher job decision latitude was associated with a lower prevalence of hypertension, prevalence ratio = 0.78 (95% confidence interval 0.66 to 0.91) for the top versus bottom quartile of job decision latitude. Associations, however, differed by occupation: decision latitude was associated with a higher prevalence of hypertension in health care support occupations (interaction P = 0.02). Occupation modified associations of sex with hypertension: a higher prevalence of hypertension in women (vs men) was observed in health care support and in blue-collar occupations (interaction P = 0.03).

CONCLUSIONS

Lower job decision latitude is associated with hypertension prevalence in many occupations. Further research is needed to determine reasons for differential impact of decision latitude and sex on hypertension across occupations.

Perceived discrimination is associated with health behaviours among African-Americans in the Jackson Heart Study

BACKGROUND

Using Jackson Heart Study data, we examined associations of multiple measures of perceived discrimination with health behaviours among African-Americans (AA).

METHODS

The cross-sectional associations of everyday, lifetime and burden of discrimination with odds of smoking and mean differences in physical activity, dietary fat and sleep were examined among 4925 participants aged 35-84 years after adjustment for age and socioeconomic status (SES).

RESULTS

Men reported slightly higher levels of everyday and lifetime discrimination than women and similar levels of burden of discrimination as women. After adjustment for age and SES, everyday discrimination was associated with more smoking and a greater percentage of dietary fat in men and women (OR for smoking: 1.13, 95% CI 1.00 to 1.28 and 1.19, 95% CI 1.05 to 1.34; mean difference in dietary fat: 0.37, p<0.05 and 0.43, p<0.01, in men and women, respectively). Everyday and lifetime discrimination were associated with fewer hours of sleep in men and women (mean difference for everyday discrimination: -0.08, p<0.05 and -0.18, p<0.001, respectively; and mean difference for lifetime discrimination: -0.08, p<0.05 and -0.24, p<0.001, respectively). Burden of discrimination was associated with more smoking and fewer hours of sleep in women only.

CONCLUSIONS

Higher levels of perceived discrimination were associated with select health behaviours among men and women. Health behaviours offer a potential mechanism through which perceived discrimination affects health in AA.

Association of neighborhood characteristics with cardiovascular health in the multi-ethnic study of atherosclerosis

BACKGROUND

The concept of cardiovascular health (CVH) was introduced as a global measure of one's burden of cardiovsacular risk factors. Previous studies established the relationship between neighborhood characteristics and individual cardiovascular risk factors. However, the relationship between neighborhood environment and overall CVH remains unknown.

METHODS AND RESULTS

We analyzed data from the Multi-Ethnic Study of Atherosclerosis baseline examination (2000–2002). Mean age was 61.6 years, and 52% were women. Ideal, intermediate, and poor categories of cholesterol, body mass index, diet, physical activity, fasting glucose, blood pressure, and smoking were defined according to the American Heart Association 2020 Strategic Goals, assigned an individual score, and summed to create an overall score. CVH scores were categorized into ideal (11–14 points), intermediate (9–10), and poor (0–8). Neighborhood exposures included favorable food store and physical activity resources densities (by 1-mile buffer), reported healthy food availability,walking/physical activity environment, safety, and social cohesion (by census tract). Multinomial logistic regression was used to determine the association of each characteristic with ideal and intermediate CVH, adjusted for demographics and neighborhood socioeconomic status. Over 20% of Multi-Ethnic Study of Atherosclerosis participants had an ideal CVH score at baseline. In fully adjusted models, favorable food stores (odds ratio=1.22; 1.06–1.40), physical activity resources(odds ratio=1.19; 1.08–1.31), walking/physical activity environment (odds ratio=1.20; 1.05–1.37), and neighborhood socioeconomic status (odds ratio=1.22; 1.11–1.33) were associated with higher odds of having an ideal CVH score.

CONCLUSIONS

Neighborhood environment including favorable food stores, physical activity resources, walking/physical activity environment, and neighborhood socioeconomic status are associated with ideal CVH. Further research is needed to investigate the longitudinal associations between neighborhood environment and CVH.

A common spatial factor analysis model for measured neighborhood-level characteristics: The Multi-Ethnic Study of Atherosclerosis

The purpose of this study was to reduce the dimensionality of a set of neighborhood-level variables collected on participants in the Multi-Ethnic Study of Atherosclerosis (MESA) while appropriately accounting for the spatial structure of the data. A common spatial factor analysis model in the Bayesian setting was utilized in order to properly characterize dependencies in the data. Results suggest that use of the spatial factor model can result in more precise estimation of factor scores, improved insight into the spatial patterns in the data, and the ability to more accurately assess associations between the neighborhood environment and health outcomes.

Assessing the need for a new nationally representative household panel survey in the United States

We introduce this special issue on the critical matter of whether the existing household panel surveys in the U.S. are adequate to address the important emerging social science and policy questions of the next few decades. We summarize the conference papers which address this issue in different domains. The papers detail many new and important emerging research questions but also identify key limitations in existing panels in addressing those questions. To address these limitations, we consider the advantages and disadvantages of initiating a new, general-purpose omnibus household panel in the U.S. We also discuss the particular benefits of starting new panels that have specific targeted domains such as child development, population health and health care. We also develop a list of valuable enhancements to existing panels which could address many of their limitations.

Examining the cross-sectional and longitudinal association between diurnal cortisol and neighborhood characteristics: Evidence from the multi-ethnic study of atherosclerosis

We examined cross-sectional and longitudinal associations between neighborhood socioeconomic status, social cohesion and safety and features of the diurnal cortisol curve including: area under the curve (AUC), wake-to-bed slope, wake-up, cortisol awakening response (CAR, wake-up to 30 min post-awakening), early decline (30 min to 2 h post-awakening) and late decline (2 h post-awakening to bed time). In cross-sectional analyses, higher neighborhood poverty was associated with a flatter early decline and a flatter wake-to-bed slope. Higher social cohesion and safety were associated with higher wake-up cortisol, steeper early decline and steeper wake-to-bed slope. Over 5 years, wake-up cortisol increased, CAR, early decline, late decline and wake-to-bed slope became flatter and AUC became larger. Higher poverty was associated with less pronounced increases in wake-up and AUC, while higher social cohesion was associated with greater increases in wake-up and AUC. Adverse neighborhood environments were cross-sectionally associated with flatter cortisol profiles, but associations with changes in cortisol were weak and not in the expected direction.

Geographic variations in cardiovascular health in the United States: contributions of state- and individual-level factors

Background

Improving cardiovascular health (CVH) of all Americans by 2020 is a strategic goal of the American Heart Association. Understanding the sources of variation and identifying contextual factors associated with poor CVH may suggest important avenues for prevention.

Methods and Results

Cross-sectional data from the Behavioral Risk Factor Surveillance System for the year 2011 were linked to state-level coronary heart disease and stroke mortality data from the National Vital Statistics System and to state-level measures of median household income, income inequality, taxes on soda drinks and cigarettes, and food and physical activity environments from various administrative sources. Poor CVH was defined according to the American Heart Association definition using 7 self-reported CVH metrics (current smoking, physical inactivity, obesity, poor diet, hypertension, diabetes, and high cholesterol). Linked micromap plots and multilevel logistic models were used to examine state variation in poor CVH and to investigate the contributions of individual- and state-level factors to this variation. We found significant state-level variation in the prevalence of poor CVH (median odds ratio 1.32, P<0.001). Higher rates of poor CVH and cardiovascular disease mortality were clustered in the southern states. Minority and low socioeconomic groups were strongly associated with poor CVH and explained 51% of the state-level variation in poor CVH; state-level factors explained an additional 28%. State-level median household income (odds ratio 0.89; 95% CI 0.84–0.94), taxes on soda drinks (odds ratio 0.94; 95% CI 0.89–0.99), farmers markets (odds ratio 0.91; 95% CI 0.85–0.98), and convenience stores (odds ratio 1.09; 95% CI 1.01–1.17) were predictive of poor CVH even after accounting for individual-level factors.

Conclusions

There is significant state-level variation in poor CVH that is partly explained by individual- and state-level factors. Additional longitudinal research is warranted to examine the influence of state-level policies and food and physical activity environments on poor CVH.

Modeling spatial segregation and travel cost influences on utilitarian walking: Towards policy intervention

We develop an agent-based model of utilitarian walking and use the model to explore spatial and socioeconomic factors affecting adult utilitarian walking and how travel costs as well as various educational interventions aimed at changing attitudes can alter the prevalence of walking and income differentials in walking. The model is validated against US national data. We contrast realistic and extreme parameter values in our model and test effects of changing these parameters across various segregation and pricing scenarios while allowing for interactions between travel choice and place and for behavioral feedbacks. Results suggest that in addition to income differences in the perceived cost of time, the concentration of mixed land use (differential density of residences and businesses) are important determinants of income differences in walking (high income walk less), whereas safety from crime and income segregation on their own do not have large influences on income differences in walking. We also show the difficulty in altering walking behaviors for higher income groups who are insensitive to price and how adding to the cost of driving could increase the income differential in walking particularly in the context of segregation by income and land use. We show that strategies to decrease positive attitudes towards driving can interact synergistically with shifting cost structures to favor walking in increasing the percent of walking trips. Agent-based models, with their ability to capture dynamic processes and incorporate empirical data, are powerful tools to explore the influence on health behavior from multiple factors and test policy interventions.

Long-term exposure to air pollution and type 2 diabetes mellitus in a multiethnic cohort

Although air pollution has been suggested as a possible risk factor for type 2 diabetes mellitus (DM), results from existing epidemiologic studies have been inconsistent. We investigated the associations of prevalence and incidence of DM with long-term exposure to air pollution as estimated using annual average concentrations of particulate matter with an aerodynamic diameter of 2.5 μm or less (PM₂.₅) and nitrogen oxides at baseline (2000) in the Multi-Ethnic Study of Atherosclerosis. All participants were aged 45-84 years at baseline and were recruited from 6 US sites. There were 5,839 participants included in the study of prevalent DM and 5,135 participants without DM at baseline in whom we studied incident DM. After adjustment for potential confounders, we found significant associations of prevalent DM with PM₂.₅ (odds ratio (OR) = 1.09, 95% confidence interval (CI): 1.00, 1.17) and nitrogen oxides (OR = 1.18, 95% CI: 1.01, 1.38) per each interquartile-range increase (2.43 µg/m(3) and 47.1 ppb, respectively). Larger but nonsignificant associations were observed after further adjustment for study site (for PM₂.₅, OR = 1.16, 95% CI: 0.94, 1.42; for nitrogen oxides, OR = 1.29, 95% CI: 0.94, 1.76). No air pollution measures were significantly associated with incident DM over the course of the 9-year follow-up period. Results were partly consistent with a link between long-term exposure to air pollution and the risk of type 2 DM. Additional studies with a longer follow-up time and a greater range of air pollution exposures, including high levels, are warranted to evaluate the hypothesized association.

Reducing health disparities: the role of sleep deficiency and sleep disorders

Decrements in sleep health, including insufficient sleep duration, irregular timing of sleep, poor sleep quality, and sleep/circadian disorders, are widespread in modern society and are associated with an array of disease risks and outcomes, including those contributing to health disparities (eg, cardiovascular disease, obesity and diabetes, psychiatric illness, and cancer). Recent findings have uncovered racial/ethnic and socioeconomic position differences in sleep health; however, the contribution of sleep deficiency to health disparities remains largely unexplored, and understanding the underlying causes of disparities in sleep health is only beginning to emerge. In 2011, the National Heart, Lung, and Blood Institute (NHLBI) convened a workshop, bringing together sleep and health disparities investigators, to identify research gaps and opportunities to advance sleep and health disparities science. This article provides a brief background and rationale for the workshop, and it disseminates the research recommendations and priorities resulting from the working group discussions.

Air pollution and percent emphysema identified by computed tomography in the Multi-Ethnic study of Atherosclerosis

BACKGROUND

Air pollution is linked to low lung function and to respiratory events, yet little is known of associations with lung structure.

OBJECTIVES

We examined associations of particulate matter (PM2.5, PM10) and nitrogen oxides (NOx) with percent emphysema-like lung on computed tomography (CT).

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) recruited participants (45-84 years of age) in six U.S. states. Percent emphysema was defined as lung regions < -910 Hounsfield Units on cardiac CT scans acquired following a highly standardized protocol. Spirometry was also conducted on a subset. Individual-level 1- and 20-year average air pollution exposures were estimated using spatiotemporal models that included cohort-specific measurements. Multivariable regression was conducted to adjust for traditional risk factors and study location.

RESULTS

Among 6,515 participants, we found evidence of an association between percent emphysema and long-term pollution concentrations in an analysis leveraging between-city exposure contrasts. Higher concentrations of PM2.5 (5 μg/m3) and NOx (25 ppb) over the previous year were associated with 0.6 (95% CI: 0.1, 1.2%) and 0.5 (95% CI: 0.1, 0.9%) higher average percent emphysema, respectively. However, after adjustment for study site the associations were -0.6% (95% CI: -1.5, 0.3%) for PM2.5 and -0.5% (95% CI: -1.1, 0.02%) for NOx. Lower lung function measures (FEV1 and FVC) were associated with higher PM2.5 and NOx levels in 3,791 participants before and after adjustment for study site, though most associations were not statistically significant.

CONCLUSIONS

Associations between ambient air pollution and percentage of emphysema-like lung were inconclusive in this cross-sectional study, thus longitudinal analyses may better clarify these associations with percent emphysema.

Testing departure from additivity in Tukey's model using shrinkage: application to a longitudinal setting

While there has been extensive research developing gene-environment interaction (GEI) methods in case-control studies, little attention has been given to sparse and efficient modeling of GEI in longitudinal studies. In a two-way table for GEI with rows and columns as categorical variables, a conventional saturated interaction model involves estimation of a specific parameter for each cell, with constraints ensuring identifiability. The estimates are unbiased but are potentially inefficient because the number of parameters to be estimated can grow quickly with increasing categories of row/column factors. On the other hand, Tukey's one-degree-of-freedom model for non-additivity treats the interaction term as a scaled product of row and column main effects. Because of the parsimonious form of interaction, the interaction estimate leads to enhanced efficiency, and the corresponding test could lead to increased power. Unfortunately, Tukey's model gives biased estimates and low power if the model is misspecified. When screening multiple GEIs where each genetic and environmental marker may exhibit a distinct interaction pattern, a robust estimator for interaction is important for GEI detection. We propose a shrinkage estimator for interaction effects that combines estimates from both Tukey's and saturated interaction models and use the corresponding Wald test for testing interaction in a longitudinal setting. The proposed estimator is robust to misspecification of interaction structure. We illustrate the proposed methods using two longitudinal studies-the Normative Aging Study and the Multi-ethnic Study of Atherosclerosis.

Race/ethnicity, residential segregation, and exposure to ambient air pollution: the Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVES

We described the associations of ambient air pollution exposure with race/ethnicity and racial residential segregation.

METHODS

We studied 5921 White, Black, Hispanic, and Chinese adults across 6 US cities between 2000 and 2002. Household-level fine particulate matter (PM2.5) and nitrogen oxides (NOX) were estimated for 2000. Neighborhood racial composition and residential segregation were estimated using US census tract data for 2000.

RESULTS

Participants in neighborhoods with more than 60% Hispanic populations were exposed to 8% higher PM2.5 and 31% higher NOX concentrations compared with those in neighborhoods with less than 25% Hispanic populations. Participants in neighborhoods with more than 60% White populations were exposed to 5% lower PM2.5 and 18% lower NOX concentrations compared with those in neighborhoods with less than 25% of the population identifying as White. Neighborhoods with Whites underrepresented or with Hispanics overrepresented were exposed to higher PM2.5 and NOX concentrations. No differences were observed for other racial/ethnic groups.

CONCLUSIONS

Living in majority White neighborhoods was associated with lower air pollution exposures, and living in majority Hispanic neighborhoods was associated with higher air pollution exposures. This new information highlighted the importance of measuring neighborhood-level segregation in the environmental justice literature.

A multilevel model of postmenopausal breast cancer incidence

BACKGROUND

Breast cancer has a complex etiology that includes genetic, biologic, behavioral, environmental, and social factors. Etiologic factors are frequently studied in isolation with adjustment for confounding, mediating, and moderating effects of other factors. A complex systems model approach may present a more comprehensive picture of the multifactorial etiology of breast cancer.

METHODS

We took a transdisciplinary approach with experts from relevant fields to develop a conceptual model of the etiology of postmenopausal breast cancer. The model incorporated evidence of both the strength of association and the quality of the evidence. We operationalized this conceptual model through a mathematical simulation model with a subset of variables, namely, age, race/ethnicity, age at menarche, age at first birth, age at menopause, obesity, alcohol consumption, income, tobacco use, use of hormone therapy (HT), and BRCA1/2 genotype.

RESULTS

In simulating incidence for California in 2000, the separate impact of individual variables was modest, but reduction in HT, increase in the age at menarche, and to a lesser extent reduction in excess BMI >30 kg/m(2) were more substantial.

CONCLUSIONS

Complex systems models can yield new insights on the etiologic factors involved in postmenopausal breast cancer. Modification of factors at a population level may only modestly affect risk estimates, while still having an important impact on the absolute number of women affected.

IMPACT

This novel effort highlighted the complexity of breast cancer etiology, revealed areas of challenge in the methodology of developing complex systems models, and suggested additional areas for further study.