Symptoms of stress and depression effect percentage of body fat and insulin resistance in healthy youth: LOOK longitudinal study

OBJECTIVE: This study examined the longitudinal and cross-sectional effects of both psychosocial stress and depressive symptoms on insulin resistance and percentage body fat in a cohort of healthy Australian children, following them from childhood into adolescence. METHOD: Participants were 791 healthy, initially Grade 2 children (7-8 years; 394 girls), selected from the general community. Psychosocial stress was assessed using the Children's Stress Questionnaire, while depressive symptoms were assessed using the Children's Depression Inventory. Fasting blood samples for serum insulin and plasma glucose were collected to calculate the homeostasis model assessment-insulin resistance (HOMA-IR). Other measurements were height, weight, percentage body fat (dual energy x-ray absorptiometry), physical activity (pedometers), and pubertal maturation (Tanner score). RESULTS: Boys who reported more symptoms of depression had higher insulin resistance, irrespective of adiposity (p = .016); and longitudinally, we found a trend for boys who developed more depressive symptoms to develop higher insulin resistance (p = .073). These findings did not extend to girls. Furthermore, boys and girls with higher depressive symptoms had a higher percentage of body fat (p = .011 and .020, respectively); and longitudinally, boys whose depressive symptoms increased became fatter (p = .046). CONCLUSION: Our data provide evidence that early symptoms of depression increase insulin resistance, independent of adiposity. Our evidence that early symptoms of depression may lead to overweight, and obesity provides further reason to suggest that early attention to children with depression, even in preclinical stages, may reduce risk of chronic disease in later life.