Community Violence Exposure and Stress Reactivity in African American and Non-Latino White Adolescents With Overweight/Obesity.

Adolescents who experience community violence are exposed to toxic stressors at a critical period of growth and development. The purpose of this study was to examine the relationship between community violence exposure and stress reactivity in African American and non-Latino white adolescents with overweight/obesity. Fifty-one adolescents (47% female, 55% African American; aged 14-19) participated in this study. Community violence was assessed using the Survey of Children's Exposure to Community Violence. Stress reactivity was assessed via salivary cortisol and alpha-amylase area under the curve (AUC) during a Trier Social Stress Test (TSST). Race was a significant predictor of alpha-amylase reactivity (ß = 10740±3665, p = 0.0006), with a higher alpha-amylase AUC observed in African American compared to non-Latino white adolescents. There was also a significant difference in the relationship between community violence exposure and alpha-amylase AUC by race (ß = -3561±1226, p = 0.007). At similar increases in violence exposure, African Americans demonstrated a significant decline in alpha-amylase AUC while non-Latino whites demonstrated a significant increase in alpha-amylase AUC. Neither race nor violence exposure were significant predictors of cortisol AUC and there were no significant differences in the relationship between community violence exposure and cortisol AUC by race (all p's > .05). These preliminary findings suggest exposure to community violence may act to exacerbate autonomic dysregulation in African American adolescents with overweight/obesity. Longitudinal studies are needed to confirm the mechanisms by which community violence exposure differentially impacts stress responses by race.

Stress coping strategies and stress reactivity in adolescents with overweight/obesity.

This study explored the associations between the frequency and effectiveness of habitual stress coping strategies on physiological and psychological stress responses to an acute laboratory stressor in adolescents with overweight/obesity (51 adolescents; 47% female; ages 14-19 years). Coping strategies were assessed using the Schoolager's Coping Strategies Inventory. Acute physiological stress responses were measured as salivary cortisol and α-amylase output during the Trier Social Stress Test and during a control condition. Acute psychological stress was measured using a Likert-type scale, and systolic blood pressure (SBP) and heart rate were measured at baseline. Results revealed that higher coping effectiveness was associated with lower log-based α-amylase during the stress (ß = -0.025, p = 0.018) and control (ß = -0.030, p = 0.005) conditions, but not with cortisol across either condition (all ps > 0.05). SBP moderated the association between coping effectiveness and α-amylase during the stress condition, with higher coping effectiveness associated with lower α-amylase only among individuals with lower SBP (ß = 0.002, p = 0.027). Coping frequency was not associated with cortisol responses, neither was habitual stress coping strategies associated with psychological stress (all ps > 0.05). These findings provide preliminary evidence that effective use of stress coping strategies may provide a dampening effect on sympathetic activity in an at-risk adolescent population.

Stress-Induced Suppression of Food Intake in Overweight and Obese Adolescents.

OBJECTIVE: Overweight adolescents exhibit greater cortisol reactivity in response to acute stress and are more likely to eat in response to emotional cues, which suggest an increased susceptibility to stress-induced eating. The purpose of this study was to examine the biological (cortisol and α-amylase reactivity) and behavioral (caloric intake) responses to an acute stressor in overweight adolescents. METHODS: Fifty-one adolescents ages 14 to 19 years (47% female, 55% white; body mass index, 31.2 ± 0.8 kg/m) were exposed to the Trier Social Stress Test and a control condition on separate days. Immediately after each condition, participants were provided with snacks to eat at their leisure. Reactivity was assessed via salivary cortisol and α-amylase area under the curve (AUC), and adolescents were categorized as high or low reactors. RESULTS: Cortisol AUC was higher during the stress condition (19.6 ± 0.2 µg/dl · min) compared with the control condition (11.4 ± 0.9 µg/dl · min, p < .001). α-Amylase AUC was not different during the stress condition (9999 ± 987 U/ml · min) compared with the control condition (8762 ± 865 U/ml · min, p = .145). Overall, adolescents consumed fewer calories during the stress condition (488 ± 51 kcal) compared with the control condition (637 ± 42 kcal, p = .007). High cortisol reactors decreased their calorie consumption from the control condition (716 ± 52 kcal) to the stress condition (457 ± 53 kcal, p = .001), whereas low cortisol reactors did not change their consumption (stress: 518 ± 87 kcal versus control: 561 ± 62 kcal, p = .574). CONCLUSION: High cortisol reactivity in overweight adolescents resulted in decreased calorie consumption after an acute stressor. Further research is needed to understand the mechanisms underlying stress-induced suppression of food intake in overweight adolescents.

Racial Discrimination and Low Household Education Predict Higher Body Mass Index in African American Youth.

OBJECTIVE: The purpose of this study was to examine the relationships between environmental factors, including household education, community violence exposure, racial discrimination, and cultural identity, and BMI in African American adolescents. METHODS: A community-based sample of 198 African American youth (120 girls, 78 boys; ages 11-19 years) from Washtenaw County, Michigan, were included in this analysis. Violence exposure was assessed by using the Survey of Children's Exposure to Community Violence; racial discrimination by using the Adolescent Discrimination Distress Index; cultural identity by using the Acculturation, Habits, and Interests Multicultural Scale for Adolescents; and household education by using a seven-category variable. Measured height and body weight were used to calculate BMI. RESULTS: Racial discrimination was positively associated with BMI, whereas household education was inversely associated with BMI in African American adolescents (discrimination: ß = 0.11 ± 0.04, p = 0.01; education: ß = -1.13 ± 0.47, p = 0.02). These relationships were significant when accounting for the confounding effects of stress, activity, diet, and pubertal development. Significant gender interactions were observed with racial discrimination and low household education associated with BMI in girls only (discrimination: ß = 0.16 ± 0.05, p = 0.003; education: ß = -1.12 ± 0.55, p = 0.045). There were no significant relationships between culture, community violence exposure, and BMI (all p's > 0.05). CONCLUSION: Environmental factors, including racial discrimination and low household education, predicted higher BMI in African American adolescents, particularly among girls. Longitudinal studies are needed to better understand the mechanisms by which these environmental factors increase obesity risk in African American youth.