[Subclinical Cushing's syndrome in populations at risk]

Based on autopsy studies, adrenal masses are among the most common tumors in humans. Endogenous Cushing's syndrome (CS) is unusual and adrenal adenomas account for 10% of all cases of CS. Patients with subclinical CS (SCS) present abnormal cortisol dynamics without obvious manifestations. The prevalence of hypercortisolism in clinically inapparent adrenal masses has been reported as 9%. Data from several small series of patients indicate that fewer than 20% develop hormone overproduction when followed for up to 10 years. Follow-up of patients with subclinical CS suggests that rarely masses increase in size or progress to overt CS. Adrenal incidentalomas and subclinical CS are related to metabolic disorders, in special to type-2 diabetes. The scarce available data suggest that treatment of hypercortisolism correct the metabolic abnormalities and blood pressure. Some studies evaluating the prevalence of subclinical CS in overweight type-2 diabetes patients suggest that it is considerably higher in populations at risk than in the general population.