The hypothalamic-pituitary-adrenal axis in abdominal obesity

Because of its rapidly increasing incidence and of severe complications lending to high morbidity and mortality rates, obesity has become a major public health concern . Abdominal obesity, which is characterized by the predominance of fat around the viscera within the peritoneal cavity, demonstrates a higher prevalence of metabolic and cardiovascular complications. Patients with abdominal obesity show clinical features that are compatible with hypercortisolism. However no typical hyperactivity of the hypothalamic-pituitary-adrenal axis has been demonstrated in obese patients. This may be caused by the lack of sensitivity of current investigations Hypersensitivity of the adrenal cortex to ACTH action may be involved In order to assess this hypothesis we have developed an intravenous intravenous ACTH 1-24 acute challenge using a physiological dose of I mu g and evaluated the cortisol response in normal-weight subjects and inobese women, which,were in their period of genital activity. After iv administration of this dose, the increase of ACTH 1-24plasma concentration was short-lived and similar to that of endogenous ACTH 1-39 during a regular morning pulse, suggesting that such a challenge may be appropriate to evaluate adrenal sensitivity. We Sound that the cortisol response is significantly higher in abdominal than in femoral obesity or than in normal-weight subjects.