Low-income children are significantly more likely to be obese, to experience chronic stress, and to have difficulty self-regulating emotions in response to stress. Socioeconomic disparities in obesity begin in early childhood and track throughout the lifespan, but the etiology of these differences is unclear. Aberrations in the functioning of the hypothalamic-pituitary-adrenal (HPA), or 'stress' axis, as seen in response to chronic or acute stressors, have been suggested as one way that stress can 'get under the skin' and lead to adverse health outcomes, including increased risk for obesity and cardiovascular disease (CVD). Perturbations in HPA axis functioning have been linked with chronic stress, obesity, and other CVD risk factors in adults, but these associations have not been examined in young children. We propose to examine self-regulation skills, HPA axis functioning, and obesity in a sample of low-income preschoolers. Specifically, we will investigate whether cortisol reactivity to stress mediates relations between difficulties with self-regulation of emotion in response to stress and increased obesity risk among these young children at risk for poor health outcomes. The proposal will address 3 aims among 150 low-income preschool-aged children: Aim 1: To examine the association between emotion regulation and child body mass index z-score. Aim 2: To examine the association between cortisol reactivity to stress and child body mass index z-score.Aim 3: To examine cortisol reactivity to stress as a mediator of the relationship between emotion regulation and child body mass index z-score.This proposal will leverage the resources of an existing NIH-funded 'Challenge Grant' study of eating behavior, diurnal cortisol patterns, and obesity, but will contribute unique data regarding cortisol reactivity to stress and its relationship with obesity risk. This effort will provide more in-depth measures of these constructs from a younger and more low-income cohort than has ever previously been studied. We will use structural equation modeling to examine associations between self-regulation, cortisol stress reactivity, and overweight risk. Study results will have implications for understanding mechanisms of stress, cortisol, and obesity risk in young children and intervention possibilities, as well as understanding the early emergence of health disparities.
|Effective start/end date||07/01/2010 → 06/30/2012|