Neighborhood Socioeconomic Environment and Risk of Type 2 Diabetes: Associations and Mediation Through Food Environment Pathways in Three Independent Study Samples
RESEARCH DESIGN AND METHODS. As part of the Diabetes Location, Environmental Attributes, and Disparities (LEAD) 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) 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 new-onset T2D cases with matched controls 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 percentage of: (1) restaurants that are fast-food, 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, rural).
RESULTS. Across studies, worse NSEE was associated with higher T2D risk. In VADR, relative availability of fast-food restaurants and supermarkets were 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.