Alcohol-induced Cushing syndrome. Hypercortisolism caused by alcohol abuse

Cushing's syndrome (CS), a rare syndrome caused by overexposure to glucocorticoids, is difficult to diagnose. The underlying causes of CS include pituitary and ectopic adrenocorticotropic hormone (ACTH) producing tumours and adrenal adenomas or hyperplasia. Alcoholism, however, can cause similar symptoms, giving rise to a so-called pseudo-Cushing state, which aggravates the differential diagnostic dilemmas of CS.

To document any specific clinical or biochemical features of alcohol-induced CS.

A Medline computer-aided search was performed to identify studies that have attempted to differentiate between alcohol-induced pseudo-Cushing and CS. Only original articles, not reviews, written in English were included. A total of 62 articles were included.

Clinical and biochemical abnormalities mimicking increased hypothalamus-pituitary-adrenal (HPA) axis activity were found in the majority of the patients, although the severity of the changes varied widely. The most frequently occurring abnormalities were: insufficient suppression after low-dose dexamethasone or increased 24-hour urinary free cortisol (UFC). After alcohol withdrawal, cortisol decreased and dexamethasone-induced suppression of cortisol increased. No differences were noted between alcoholic and control subjects after an ACTH stimulation test, insulin tolerance test or metyrapone test. Differences were found after a naloxone test and hexarelin test. Studies using corticotropin-releasing hormone stimulation and tests after ethanol ingestion revealed inconclusive results.

There is no clear definition for the alcohol-induced pseudo-Cushing state, and hitherto studies fail to provide clues to differentiate between pseudo-Cushing and Cushing's syndrome. Only cessation of alcohol can normalise biochemical abnormalities and regress hypercortisolic symptoms.