Race/ethnicity and age associations with hair cortisol concentrations among children studied longitudinally from early through middle childhood.

A total of 513 children were included in this secondary analysis of data from the NET-Works trial of low income children at risk for obesity. The purpose of the analysis was to examine HCC longitudinally over 5 assessments from early through middle childhood with the goal of i) determining if there were racial/ethnic differences in HCC, and if so, how early in childhood these differences could be observed; and (ii) whether racial/ethnic differences in HCC reflected structural and family-level indicators of disadvantage. The sample consisted of children from diverse racial/ethnic backgrounds: Black, including Hispanic Black (N = 156), non-Hispanic White (N = 67) and Non-Black Hispanic (N = 290) children. As the largest group, the last group was used as the reference group in analyses. Structural and family-level indicators of disadvantage, including the neighborhood child opportunity index (COI), family income, and parent perceived neighborhood safety, were collected at each assessment. The results showed higher HCC among Black children beginning as early as 2-4 years of age than non-Black Hispanic children who did not differ from non-Hispanic White children. Although family income and COI were lower for children from minoritized racial-ethnic backgrounds, entering these measures as covariates did not reduce the difference in HCC between Black children and the other two groups. The results also showed that HCC initially decreased with age and then plateaued, with no evidence that this pattern differed by race/ethnicity. Because of the potential health risks of chronically elevated cortisol concentrations, these data argue for increased attention to the myriad of factors (oppressive structures, systems, and interpersonal experiences) that likely contribute to elevated cortisol levels among Black children.