Epidemiology and mortality of Cushing's syndrome.

Endogenous Cushing's syndrome (CS) is a rare endocrine disorder characterised by excess cortisol secretion due to either ACTH-dependent conditions [commonly an ACTH-producing pituitary adenoma (Cushing's disease)] or ACTH-independent causes (with most common aetiology being a benign adrenal adenoma). Overall, the annual incidence of CS ranges between 1.8 and 3.2 cases per million population. Mortality in active CS is elevated compared to the general population, and a number of studies support the view that survival is also compromised even after apparent successful treatment. The main cause of death is cardiovascular disease highlighting the negative impact of cortisol excess on cardiovascular risk factors. Early diagnosis and prompt treatment of the cortisol excess, as well as vigilant monitoring and stringent control of cardiovascular risk factors are key elements for the long-term prognosis of these patients.