Objective: Identification of early risk factors related to obesity is critical to preventative public health efforts. In this study, we investigated links between the Hypothalamic-Pituitary-Adrenal (HPA)-axis activity (diurnal cortisol pattern), geospatially operationalized exposure to neighborhood crime, and body mass index (BMI) for a sample of 5-year-old children. Greater community crime exposure and lower HPA-axis activity were hypothesized to contribute to higher BMI, with child HPA-axis moderating the association between crime exposure and BMI.
Method: Families residing within the boundaries of the City of Seattle (N = 114) provided information concerning demographic/psychosocial risk factors, used to calculate a Cumulative Risk Index, indicating the number of contextual adversities present. Child BMI and diurnal cortisol pattern (derived from assays of saliva samples) were examined, along with neighborhood crime indices computed with publically available information, based on participants' locations.
Results: Hierarchical multiple regression analyses, adjusted for covariates (cumulative risk, age, and sex), indicated that crime proximity made a unique contribution to child BMI, in the direction signaling an increase in the risk for obesity. Consistent with our hypothesis, a significant interaction was observed, indicative of moderation by diurnal cortisol pattern. Follow-up simple slope analyses demonstrated that crime exposure was significantly related to higher BMI for children with low-flat (blunted) diurnal cortisol patterns, where community crime and BMI were not significantly associated at higher levels of cortisol.
Conclusion: Community crime exposure contributes to higher BMI as early as the preschool period, and blunted diurnal cortisol patterns may place children experiencing neighborhood adversity at greater risk for obesity.