Chronic Psychosocial Stress, Cognitive Control And Obesity Among Adolescents-A Two-year Cohort Study

BackgroudOverweight and obese adolescents is increasing recently. Rapid increases in childhood obesity portend disastrous health consequences given that excess childhood adiposity tracks into adulthood and is accompanied by elevated chronic metabolic disorders.The existing epidemiology has shown that psychological stress has been linked with weight gain in children and adolescents through a variety of mechanisms. Chronic stress invokes overeating and weight gain in part because of perturbations in physiologic mechanisms that regulate eating. Elevated glucocorticoids, including cortisol, cause the body to increase energy expenditure, which in turn signals the brain to increase caloric input necessary for the provision of glycogen and fat. On the other hand, weight gain is a product of caloric intake and energy expenditure, central regions of the brain associated with self-control ability is impaired under the chronic stress exposure. Restrictions in caloric intake and weight gain need cognitive-control ability, so this research evaluate chronic psychosocial stress predict BMI change in adolescents, and how emotional cognitive regulation mediate the association between stress and obesity. As the same time, we asses the relations between stress response-self control network and obesity by neuropsychological studyObjectivesTo clarify whether chronic psychosocial stress induce obesity and the role of cognitive control in the relationship between psychosocial stress and obesity. The objectives including:I To investigate whether chronic psychosocial stress induce BMI change in adolescents.Ⅱ To identify an underlying mechanism, cognitive emotion regulation for the stress-BMI link, and tested whether cognitive emotion regulation mediated chronic psychosocial stress and weight gain in overweight and obese adolescence.Ⅲ To test the relations between stress response-cognitive control network and obesity by neuropsychological study.MethodsIn Sep2011, the participants were from the7th and10th grade students from10urban junior and high schools in Xuzhou city, and height and weight were measured at baseline.They were instructed to self-report informations on sociodemographic data, emotional symptoms (depressive symptoms, anxiety symptoms), and life style and behavior. Chronic psychosocial stress was assessed with Multidimensional Life Events Rating Questionnaire (MLERQ). This instrument has five items that focus on the appraisal of stress of family life, school life, peer relation, sex relation and health and growth. A total of5473valid questionnaires were retained for analysis (2841males and2632female). The second follow-up measured of height and weight were carried out in Sep2013.4316valid data (2171males2145females) were collected at baseline and2-year follow-up, and the missing data were1,157. One hundred and seven overweight and obese females were selected from the7th and10th grade students at baseline. They were instructed to self-report informations on psychosocial stress, cognitive emotion regulation, as well as BMI data at baseline and follow-up survey. Chronic psychosocial stress and cognitive emotion regulation were assessed with Multidimensional Life Events Rating Questionnaire (MLERQ) and Cognitive Emotion Regulation Questionnaire (CERQ). Participants in this study were selected from grade8th, and anthropometry measurement were assessed among39girls aged12-13years. Twenty girls were obese and the19age-(±3months), height-(±3cm), class-matched girls with normal puberty and normal weight. The cortisol reactivity to Trier Social Stress Test for Children (TSST-C) and delay discounting (DD) were measured. ResultsIn females, chronic stress score was positive associated with BMI-Z score at baseline after controlling for age, tanner stage, SES, emotional symptoms and life style and behaviors. In overweight and obese females at baseline, the effect of high chronic psychosocial stress on BMI-Z gain was dependent on baseline BMI-Z (P<0.01). No corresponding effect was seen among adolescent males at baseline survey or follow-up survey.Overweight and obese adolescent females exposed to a greater level of chronic stress showed larger gains in BMI over the follow-up two years period. These gains in BMI during the period are partly accounted for by cognitive emotion regulation abilities among overweight and obese adolescents facing more chronic stress.The obese group had higher cortisol reactivity (P=0.05) and greater delay discounting (P<0.01) than normal weight group. In the obese group, greater delay disounting was associated with higher cortisol reactivity (P=-0.37, P=0.05), however, this association in the normal weight group was not statistically significant.ConclusionsHigh level of chronic psychosocial stress leads to BMI gain in overweight and obese adolescent females. In light of our results, the susceptibility of overweight and obese female individuals should also be taken into account. It is essential to understand the underlying mechanisms that link stress to weight gain suggesting that cognitive emotion regulation may also be an important component of weight-loss interventions in overweight and obese adolescents. Higher cortisol reactivity under stress was associated with greater delay discounting in obese female adolescents. The hyperactive HPA axis may lead to overeating comfort food due to loss of delay of gratification, and may induce to obesity.