ONTOGENY AND MAINTENANCE OF REGIONAL FAT DISTRIBUTION

肥胖及其伴随的疾病影响了多达25%的美国人

Obesity, and its attendant morbidities affect as many as 25% of the adult and pediatric population of the United States and represent incalculable costs in terms of health care and monies spent on fat diets and other means of weight reduction. Epidemiologic studies have demonstrated that the distribution of fat in central (abdominal) versus peripheral (gluteal) depots is as, or more, important than absolute fatness as an indicator of the risk of adiposity-related morbidities such as diabetes, hypertension, hyperlipidemia, myocardial infarction, and cerebrovascular disease. Studies in this laboratory and elsewhere have reported that the individual adult somatotype tends to persist over wide fluctuations in body weight. Studies of regional adipose tissue samples have shown that abdominal fat is significantly more responsive to beta-adrenergic (lipolytic) stimuli while gluteal fat is strikingly more responsive to alpha-adrenergic (anti-lipolytic) stimuli and that these regional differences in adrenoreceptor status are not present in pre-pubertal children. Since the adult body habitus persist over time, it is highly desirable to further delineate those processes which are involved in the ontogeny and maintenance of the individual somatotype. The regional adrenoreceptor status differences noted above would tend to favor a more central or "male" type adipose tissue distribution. This study proposes to examine abdominal and gluteal subcutaneous adipose tissue samples from children at various pubertal stages and from adults to determine at what point the "adult type" regional adrenoreceptor status differences become evident and to examine subcellular mechanisms which are likely mediators of these differences. In addition, anthropometric data will be collected on a large population of children and adults exposed to pre- and post-natal states of hypo- and hyper- androgenism to determine whether there is a point at which exposure to androgens results in "imprinting" on fat depots which affects the adult somatotype.