Access to quality health resources and environmental toxins affect the relationship between brain structure and BMI in a sample of pre and early adolescents.

BACKGROUND

Environmental resources are related to childhood obesity risk and altered brain development, but whether these relationships are stable or if they have sustained impact is unknown. Here, we utilized a multidimensional index of childhood neighborhood conditions to compare the influence of various social and environmental disparities (SED) on body mass index (BMI)-brain relationships over a 2-year period in early adolescence.

METHODS

Data were gathered the Adolescent Brain Cognitive Development Study ( = 2,970, 49.8% female, 69.1% White, no siblings). Structure magnetic resonance imaging (sMRI), anthropometrics, and demographic information were collected at baseline (9/10-years-old) and the 2-year-follow-up (11/12-years-old). Region of interest (ROIs; 68 cortical, 18 subcortical) estimates of cortical thickness and subcortical volume were extracted from sMRI Tw images using the Desikan atlas. Residential addresses at baseline were used to obtain geocoded estimates of SEDs from 3 domains of childhood opportunity index (COI): healthy environment (COI), social/economic (COI), and education (COI). Nested, random-effects mixed models were conducted to evaluate relationships of BMI with (1) ROI COI and (2) ROI COI Time. Models controlled for sex, race, ethnicity, puberty, and the other two COI domains of non-interest, allowing us to estimate the unique variance explained by each domain and its interaction with ROI and time.

RESULTS

Youth living in areas with lower COI and COI scores were heavier at the 2-year follow-up than baseline and exhibited greater thinning in the bilateral occipital cortex between visits. Lower COI scores corresponded with larger volume of the bilateral caudate and greater BMI at the 2-year follow-up. COI scores showed the greatest associations ( = 20 ROIs) with brain-BMI relationships: youth living in areas with lower COI had thinner cortices in prefrontal regions and larger volumes of the left pallidum and Ventral DC. Time did not moderate the COI x ROI interaction for any brain region during the examined 2-year period. Findings were independent of family income (i.e., income-to-needs).

CONCLUSION

Collectively our findings demonstrate that neighborhood SEDs for health-promoting resources play a particularly important role in moderating relationships between brain and BMI in early adolescence regardless of family-level financial resources.