Subclinical Hypercortisolism: How to Deal with It?

Subclinical hypercortisolism (SH) is a condition of mild cortisol excess, found in the 5-30% of patients with adrenal incidentalomas, defined as silent adrenal masses diagnosed throughout radiological examinations performed for unrelated diseases. Generally, the diagnosis of SH is supported by the presence of high cortisol levels after a 1-mg dexamethasone suppression test, low adrenocorticotropic hormone levels, altered cortisol circadian rhythm and 24-hour urinary free cortisol levels higher than the upper reference value. Less frequently, diagnosis is made by other tests. Unfortunately, up to now a consensus on SH diagnostic criteria is lacking. Although SH is characterized by the absence of the classical features of Cushing's syndrome by definition, it has been associated with the presence of different metabolic complications (mainly type 2 diabetes mellitus, arterial hypertension, central obesity and dyslipidemia), cardiovascular diseases, osteoporosis and vertebral fractures, altered coagulation parameters, worsening of quality of life, and increased mortality. The management of SH, as well as the improvement of metabolic parameters and other complications after surgical treatment, is still a matter of debate.