Mediation of an association between neighborhood socioeconomic environment and type 2 diabetes through the leisure-time physical activity environment in an analysis of three independent samples.

INTRODUCTION: Inequitable access to leisure-time physical activity (LTPA) resources may explain geographic disparities in type 2 diabetes (T2D). We evaluated whether the neighborhood socioeconomic environment (NSEE) affects T2D through the LTPA environment. RESEARCH DESIGN AND METHODS: We conducted analyses in three study samples: the national Veterans Administration Diabetes Risk (VADR) cohort comprising electronic health records (EHR) of 4.1 million T2D-free veterans, the national prospective cohort REasons for Geographic and Racial Differences in Stroke (REGARDS) (11 208 T2D free), and a case-control study of Geisinger EHR in Pennsylvania (15 888 T2D cases). New-onset T2D was defined using diagnoses, laboratory and medication data. We harmonized neighborhood-level variables, including exposure, confounders, and effect modifiers. We measured NSEE with a summary index of six census tract indicators. The LTPA environment was measured by physical activity (PA) facility (gyms and other commercial facilities) density within street network buffers and population-weighted distance to parks. We estimated natural direct and indirect effects for each mediator stratified by community type. RESULTS: The magnitudes of the indirect effects were generally small, and the direction of the indirect effects differed by community type and study sample. The most consistent findings were for mediation via PA facility density in rural communities, where we observed positive indirect effects (differences in T2D incidence rates (95% CI) comparing the highest versus lowest quartiles of NSEE, multiplied by 100) of 1.53 (0.25, 3.05) in REGARDS and 0.0066 (0.0038, 0.0099) in VADR. No mediation was evident in Geisinger. CONCLUSIONS: PA facility density and distance to parks did not substantially mediate the relation between NSEE and T2D. Our heterogeneous results suggest that approaches to reduce T2D through changes to the LTPA environment require local tailoring.

Neighborhood Socioeconomic Environment and Risk of Type 2 Diabetes: Associations and Mediation Through Food Environment Pathways in Three Independent Study Samples.

OBJECTIVE: We examined whether relative availability of fast-food restaurants and supermarkets mediates the association between worse neighborhood socioeconomic conditions and risk of developing type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: As part of the Diabetes Location, Environmental Attributes, and Disparities Network, three academic institutions used harmonized environmental data sources and analytic methods in three distinct study samples: 1) the Veterans Administration Diabetes Risk (VADR) cohort, a national administrative cohort of 4.1 million diabetes-free veterans developed using electronic health records (EHRs); 2) Reasons for Geographic and Racial Differences in Stroke (REGARDS), a longitudinal, epidemiologic cohort with Stroke Belt region oversampling (N = 11,208); and 3) Geisinger/Johns Hopkins University (G/JHU), an EHR-based, nested case-control study of 15,888 patients with new-onset T2D and of matched control participants in Pennsylvania. A census tract-level measure of neighborhood socioeconomic environment (NSEE) was developed as a community type-specific z-score sum. Baseline food-environment mediators included percentages of 1) fast-food restaurants and 2) food retail establishments that are supermarkets. Natural direct and indirect mediating effects were modeled; results were stratified across four community types: higher-density urban, lower-density urban, suburban/small town, and rural. RESULTS: Across studies, worse NSEE was associated with higher T2D risk. In VADR, relative availability of fast-food restaurants and supermarkets was positively and negatively associated with T2D, respectively, whereas associations in REGARDS and G/JHU geographies were mixed. Mediation results suggested that little to none of the NSEE-diabetes associations were mediated through food-environment pathways. CONCLUSIONS: Worse neighborhood socioeconomic conditions were associated with higher T2D risk, yet associations are likely not mediated through food-environment pathways.

Residential instability, neighborhood deprivation, and pediatric asthma outcomes.

INTRODUCTION: Limited work has directly compared the role of different neighborhood factors or examined their interactive effects on pediatric asthma outcomes. Our objective was to quantify the main and interactive effects of neighborhood deprivation and residential instability (RI) on pediatric asthma outcomes. METHODS: We conducted a retrospective cross-sectional study of patients with a primary diagnosis of asthma hospitalized at a tertiary care pediatric hospital. Residential addresses at the index hospitalization were linked to the state area deprivation index (ADI). RI was coded as the number of residences in the past 4 years. Logistic and ordinal regression and Cox regression survival analyses were used to estimate the effect on the primary outcomes of chronic asthma severity (intermittent, mild persistent, moderate persistent, severe persistent/other) as defined by the National Heart, Lung, and Blood Institute, severe hospitalization (requiring continuous albuterol or intensive care unit care), and time to emergency department (ED) readmission and rehospitalization within 365 days of the index visit, respectively. RESULTS: In the sample (N = 664), 21% had severe persistent/other asthma, 22% had severe hospitalization, 37% were readmitted to the ED, and 19% were rehospitalized. Increasing RI was independently associated with more severe chronic asthma (odds ratio = 1.18, 95% confidence interval [CI] = 1.05, 1.32, P = .004), greater risk of 365-day ED readmission (hazard ratio [HR] = 1.10, 95% CI = 1.05, 1.15, P < .0001), and greater risk of 365-day rehospitalization (HR = 1.09, 95% CI = 1.03, 1.14, P = .002). There were no significant associations between ADI and these outcomes. Further, we did not find significant evidence of interactive effects. CONCLUSIONS: RI appears to be modestly associated with pediatric asthma outcomes, independent of current neighborhood deprivation.

Area Deprivation as a Risk Factor for Methicillin-resistant Staphylococcus aureus Infection in Pediatric Cystic Fibrosis.

BACKGROUND: In US cystic fibrosis (CF) patients, methicillin-resistant Staphylococcus aureus (MRSA) rates have tripled in the past 2 decades. Known clinical risk factors include exposure to a healthcare setting, Pseudomonas aeruginosa and CF-related diabetes. Area-level socio-environmental exposures have not been evaluated. We explored the association of area-level deprivation with MRSA prevalence in a pediatric CF Center in the Southeastern United States. METHODS: Patients' residential addresses were geocoded and linked to a composite Area Deprivation Index and Rural-Urban Commuting Area scores. The association of MRSA with Area Deprivation Index and Rural-Urban Commuting Area scores was evaluated using logistic regression with robust standard errors adjusted for sociodemographic covariates (age, sex, race, mother's and father's education and household income), clinical risk factors (P. aeruginosa, CF-related diabetes, hospitalizations and number of clinic visits) and clustering. RESULTS: The study included all pediatric patients (N = 231; mean age 12) at a single CF Center. MRSA was present in 44% of subjects. Higher area-level deprivation was correlated with rural residence, lack of parental college education and lower household income (P < 0.001 for each). In a multiple regression model fully adjusted for patient-level sociodemographic covariates, clinical risk factors and clustering, neighborhood deprivation was associated with more than 2-fold increase in the odds of having MRSA [OR 2.26 (1.14-4.45), P < 0.05]. CONCLUSIONS: Neighborhood deprivation is a risk factor for MRSA in pediatric CF, doubling the odds of infection. Community-level socioeconomic risk factors should be considered when developing prevention strategies and treatment plans for MRSA infection in pediatric patients with CF.

The Role of Perceived Discrimination in Obesity Among African Americans.

INTRODUCTION: African Americans, especially those in the South, suffer a disproportionate burden of obesity and are at high risk for perceived discrimination (PD). This study investigates the association between PD and weight status among African Americans and clarifies the role of perceived stress and health behaviors in this relationship. METHODS: Data came from the Jackson Heart Study, Examination 1 (2000-2004; analyses conducted in 2016 using Stata, version 14). African Americans from Jackson, Mississippi, aged 21-95 years were recruited (N=5,301). Weight status was measured using anthropometric data with BMI; waist circumference (in centimeters); and obesity class (I, II, III). Survey instruments were used to measure PD, perceived global stress, and health behaviors. Multivariate regression was used to model weight status outcomes as a function of PD, perceived stress, and health behaviors. RESULTS: After controlling for sociodemographic factors and health status, perceived everyday discrimination was associated with higher BMI (b=0.33, p<0.01); higher waist circumference (b=0.70, p<0.01); and higher relative risk of Class III obesity versus non-obesity (relative risk ratio, 1.18; p<0.001). Global perceived stress was linked to higher BMI (b=0.42, p<0.05) and higher waist circumference (b=1.18; p<0.01) and partially mediated the relationships between PD and these weight status outcomes. Health behaviors led to suppression rather than mediation between PD and weight status and between stress and weight status. CONCLUSIONS: PD and perceived stress are potential risk factors for higher weight status. They should be considered as a part of a comprehensive approach to reduce obesity among African Americans.