PILOT D: Currently, about two-thirds of American adults are overweight or obese. African Americans and Hispanic Americans have greater rates of obesity than Caucasian Americans. Thus, the health burden of obesity falls disproportionately on minority populations. The increased incidence of obesity and the low success rate of dietary weight loss programs have resulted in an increased use of surgical intervention to treat morbid obesity. Weight loss associated with bariatric surgery helps normalize metabolic profiles, so that the incidence of insulin resistance/diabetes and hypertension are reduced. This suggests that minority populations would benefit greatly from bariatric surgery. However, some studies indicate that African Americans do poorly after gastric banding bariatric surgery, losing only 11% of excess weight. Weight loss rates after bariatric surgery in Hispanic Americans have not been adequately documented. It is important to determine 'success' of surgical interventions for obesity from standpoints other than weight loss. Among obese individuals, racial/ethnic differences have been identified in fasting hormone levels and in hormonal responses to meals. Hormones associated with hunger and/or satiety may be altered as a result of bariatric surgery itself, and this may either help or hinder weight loss efforts. Whether ethnic differences in surgical outcomes are related to such physiological factors has not been documented. Similarly, perceived stress and stress tolerance may impact adherence to post-surgical diets. Because of the predominant behavioral features of obesity and the need to reduce ethnic disparities in the incidence of Type 2-diabetes, it is important to determine the psychophysiological mechanism of appetite regulation. Whether ethnic differences in weight loss after bariatric surgery are related to psychological factors needs to be established. Therefore, the overall goals of this study are twofold: 1) to compare cardiovascular, hormonal, and metabolic status of morbidly obese Caucasian, African American, and Hispanic women, prior to, six months after, and twelve months after bariatric surgery; and 2) to determine ethnic differences in relationships among psychophysiological responses to stress, eating behaviors, and hormonal and autonomic activation in obesity. The following specific aims will be tested:
Aim 1 : To test the hypothesis that ethnic differences in weight loss after laparoscopic banding surgery are associated with differences in hormonal responses to meals and in hunger perception.
Aim 2 : To test the hypothesis that ethnic differences exist in the association between appetite and the autonomic nervous system response to induced psychological stress.
Aim 3 : To test the hypothesis that ethnic differences in psychological functioning and perceived stress will impact eating behavior and weight loss after bariatric surgery.
Showing the most recent 10 out of 41 publications
