Psychological and metabolic correlates of obesity in african-americans and caucasions /

by Oates, Christie S

Title of Thesis: Psychological and Metabolic Correlates of Obesity in African-Americans and Caucasians Christie S. Oates, Master of Science, 2006 Thesis directed by: Martha M. Faraday, Ph.D. Assistant Professor Department of Medical and Clinical Psychology The purpose of the present study was to identify whether there are unique biological, behavioral, psychological, and environmental factors specific to African- Americans that may promote the development of obesity. Chronic stress levels and the hormonal and metabolic responses of 63 Caucasian and African-American men and women to two metabolically-relevant events — a metabolic load (standardized meal) and a metabolic demand (standardized exercise) were assessed. The hormonal and metabolic responses included hypothalamic-pituitary-adrenal axis hormones (i.e., adrenocorticotropin hormone and cortisol) and insulin responses to a meal. African- Americans reported higher levels of perceived chronic stress, but had lower plasma levels of the stress hormone cortisol than did Caucasians at baseline and throughout both testing sessions. Acute insulin responses and total insulin production to a meal were significantly higher among African-Americans compared to Caucasians. Striking ethnic differences emerged in the psychological factors that mediate responses to stress and predict health behaviors, such that African-Americans reported less social support, less rest/sleep, and more negative appraisal than Caucasians. Overall, the biological (i.e., acute insulin responses and total insulin production in response to a meal) and psychological findings (i.e., higher chronic stress, less social support, less rest/sleep, and iv more negative appraisal) in overweight but otherwise healthy African-Americans compared to healthy, overweight Caucasians suggest a high vulnerability for the early onset of metabolic disorders such as obesity. v Psychological and Metabolic Correlates of Obesity in African-Americans and Caucasians by Christie S. Oates Master’s Thesis submitted to the Faculty of the Department of Medical and Clinical Psychology Graduate Program of the Uniformed Services University of the Health Sciences in partial fulfillment of the requirements for the degree of Master of Science 2006 vi