Pediatric chronic pain is common and predicts risk for psychological and pain problems into adulthood. Biopsychosocial risk factors for the development of chronic pediatric pain have been examined, but the key health behavior of caloric consumption has not been explored. Adult and animal data suggest that caloric intake is positively related to chronic pain, and that adiposity and stress-related biological factors may serve as potential mediators. This study predicted that among children: 1) adiposity, flattened diurnal cortisol slopes, and caloric consumption are related to chronic pain, and 2) the caloric consumption—pain relation is mediated by elevated adiposity and/or flattened diurnal cortisol slopes. Methods: Twin children (N = 733) were drawn from the Arizona Twin Project sample. Measures included caregiver-reported caloric intake via five daily food diaries (Age-8); adiposity (composite of waist circumference, body mass index, body fat percentage) and diurnal cortisol slopes via three days of salivary cortisol sampling (Age-9); and caregiver-reported monthly chronic pain (Age-10). Results: Multilevel models (accounting for clustering within families) with sex, age, socioeconomic status, puberty, race/ethnicity as covariates, showed that caloric intake predicted greater waist circumference, which in turn predicted elevated chronic pain. However, adiposity, waist circumference, and diurnal cortisol slopes did not mediate the caloric intake-chronic pain relation. Discussion: Consistent with the literature, caloric intake predicted adiposity, and adiposity predicted pain in a diverse sample of children. More comprehensive assessment of behavioral (sleep, diet quality) and biopsychosocial factors (e.g. inflammation, cortisol; injury; catastrophizing) may aid efforts to prevent pediatric chronic pain.

Latinos make up the fastest growing ethnic minority group in the United States and are at higher risk for the developmental of internalizing symptoms in adolescence than other ethnic groups (Merikangas et al., 2010). Rumination has been identified as a transdiagnostic risk factor associated with several internalizing disorders such as depression, anxiety, and comorbidities of the two (McLaughlin & Nolen-Hoeksema, 2011; Nolen-Hoeksema et al., 2008). Further, indicators of the hypothalamic-pituitary-adrenal (HPA) axis (i.e., flatter diurnal cortisol slopes [DCS] and greater cortisol awakening responses [CAR]) are associated with greater risk of internalizing disorders and chronic stress (Adam et al., 2010; Adam et al., 2017). Notably, no studies have examined the association between rumination and the diurnal cortisol slope in Latino populations, and literature on the relation of rumination and the CAR is mixed (Cropley et al., 2015; Hilt et al., 2017; Zoccola et al., 2011). Leveraging self-reported rumination as well as gold-standard salivary cortisol collection procedures (Stalder et al., 2016), the current study sought to elucidate associations between daily rumination and diurnal cortisol in an adolescent Latino sample by examining gender differences and bicultural competence as potential moderators of this association. Results indicated a significant but small association between night-before rumination on problems/stress and next-day DCS. Further, gender differences were detected in the effects of same-day rumination and the CAR. Greater rumination on feelings was associated with a smaller CAR the same day in males, while greater rumination on problems/stress was linked with a greater CAR the same day in females. In addition, there were no buffering effects of bicultural competence. Findings inform future research regarding potential bidirectional relations of daily rumination and the CAR, as well was how different kinds of daily rumination may have differing associations with the CAR of males and females.