Internalizing and externalizing problems in obese children and adolescents: associations with daily salivary cortisol concentrations

OBJECTIVE: Pediatric obesity commonly co-exists with emotional and behavioral disorders, while disturbed cortisol concentrations have been reported in both obese and chronically stressed individuals with anxiety and/or depression. We investigated the prevalence of internalizing and externalizing problems, reported by both parents and children, in a clinical population of obese children (OC) compared to normal-weight children. We examined the role of cortisol as a potential mediator between obesity and such problems. DESIGN: We compared 110 obese with 31 normal-weight children. The Greek version of the child behavior checklist (CBCL) and the youth self-report (YSR) were used and salivary cortisol was determined serially five times a day. RESULTS: T-scores of internalizing problems (anxiety/depression, social withdrawal, somatic complains) reported by both children (49.3 +/- 12.3 vs. 43.2 +/- 9.1) and mothers (60.6 +/- 11.3 vs. 50.6 +/- 10.4) were significantly higher (p=0.03 and p<0.001, respectively) in the obese than in the lean children. Externalizing problems (delinquency, rule-breaking behaviors) reported only by mothers were significantly higher in the OC (57.2 +/- 10.5 vs. 48.2 +/- 13.3, p=0.003). The cortisol area under the curve (AUC) was significantly smaller (p=0.03) in the OC than in the controls; however, a cortisol correlation with internalizing/externalizing symptoms was not observed. CONCLUSIONS: There is a high prevalence of internalizing and externalizing problems in a clinical population of OC. A mediation effect of cortisol in the relation between internalizing/externalizing problems and obesity could not be supported.