Subclinical hypercortisolism among outpatients referred for osteoporosis

It is well known that hypercortisolism causes osteoporosis. Aim of the study is to evaluate the prevalence of subclinical hypercortisolism in 219 consecutive out-patients 44 to 72 years of age with suspected idiopathic osteoporosis.These individuals had no known secondary cause of osteoporosis, had not received drugs known to influence bone or cortisol, and had no apparent signs or symptoms of overt Cushing syndrome. Hypercortisolism was screened with serum cortisol level after an overnight dexamethasone suppression test, and confirmed by 24-h urinary free cortisol levels, midnight plasma cortisol measurement , and the 2 mg , 2-day dexamethasone test. Overall, 3.3% of 212 patients who completed the study had abnormal responses to these tests, and were considered to have subclinical hypercortisolism. Among the 65 patients with BMD T-score < 2.5 and with vertebral fractures, the prevalence of subclinical hypercortisolism increased to 10.8% . Hypercortisolism was due to mono- or bilateral hypersecreting adrenal masses in 6 patients, and to a pituitary ACTHoma In one patient. In conclusion subclinical hypercortisolism may be much more common than is generally recognized in patients with osteoporosis and fractures, in whom other secondary causes of osteoporosis have been excluded.