The Relationship of Disordered Eating Attitudes with Stress Level, Bone Turnover Markers, and Bone Mineral Density in Obese Adolescents

OBJECTIVE To investigate the effect of stress caused by disordered eating attitudes on bone health in obese adolescents. METHODS A cross-sectional study comprising 80 obese adolescents was performed from November 2013 to September 2014. Twenty-four-hour urinary free cortisol levels were measured as a biological marker of stress. Bone turnover was evaluated using bone-specific alkaline phosphatase, serum osteocalcin, and urinary N-telopeptide concentrations. Bone mineral density was measured using dual-energy X-ray absorptiometry. The Eating Disorder Examination Questionnaire, Dutch Eating Behavior Questionnaire, Children's Depression Inventory, and the State-Trait Anxiety Inventory for Children were used to assess eating disorders, depression, and anxiety. Psychiatric examinations were performed for binge eating disorders. RESULTS In the Pearson's correlation test, a positive correlation was found between the 24-hour urinary cortisol level and Dutch Eating Behavior Questionnaire total and restrained eating subscale scores (p<0.05 for both). In linear regression analyses, the Dutch Eating Behavior Questionnaire total and restrained eating subscale scores were found to be significant contributors for urinary cortisol level (β=1.008, p=0.035; β=2.296, p=0.014, respectively). The femoral neck areal bone mineral density was found to be significantly higher in subjects who had binge eating disorder compared with those without binge eating disorder (p=0.049). CONCLUSION Despite the lack of apparent effects on bone turnover and bone mineral density in our obese adolescents at the time of the study, our results suggest that disordered eating attitudes, and especially restrained eating attitudes, might be a source of stress. Therefore, studies in this area should continue.