Type 2 Diabetes, Obesity and Cortisol Excess

Mild and asymptomatic hypercortisolism has been described to be associated with increased prevalence of chronic complications of cortisol excess, such as osteoporosis, hypertension, type 2 diabetes (T2D) and obesity and with increased mortality. In patients with osteoporosis, hypertension, T2D or obesity, this form of hypercortisolism may remain occult (hidden hypercortisolism, HidHyCo), until its presence is suspected on the basis of particular characteristics of the underlying diseases. The HidHyCo prevalence in the general population is estimated to be 0.2-2%, but it has been suggested to be even higher (up to 10%) in some specific populations as for example in patients T2D. Data regarding the prevalence of HidHyCo in obese populations are limited, Therefore, the issue of which diabetic or obese patient has to be screened for HidHyCo has recently become a widely debated topic. Therefore, the aims of the present study protocol are to assess: i) the HidHyCo prevalence in a sample of T2D patients and the clinical characteristics more frequently associated with the HidHyCo presence; ii) the HidHyCo prevalence in an adequate sample of obese patients without T2D and the clinical characteristics more frequently associated with the HidHyCo presence.

All T2D and obese-without T2D patients between 18 and 75 years of age, consecutively referred to the out-patient clinics for Diabetes and Obesity of our center will be assessed for possible inclusion. At the enrolment in all patients anthropometric e biochemical variables will be recorded. At the enrolment we will evaluate cortisol levels after dexamethasone suppression test (F-1mgDST) in all T2D and obese-without T2D patients, who have been included in the study and who have given the informed consent to participate in the study. In all subjects with F-1mgDST \>1.8 μg/dL, cortisol levels after two-day low dose (2 mg/day) dexamethasone suppression test (F-2mgx2dDST) will be performed. Patients with F-2mgx2dDST above \>1.8 μg/dL will be considered affected with possible HidHyCo and will be studied following the available guidelines for the diagnosis of hypercortisolism.