Testosterone concentrations in men on chronic glucocorticosteroid therapy.

To determine whether free (or active) testosterone concentrations are reduced in men receiving glucocorticosteroids for chronic inflammatory diseases, 17 men (mean age 55.5 years) receiving a mean daily dose of 16.3 mg prednisolone, and 13 control patients (mean age 52.2 years) receiving no prednisolone, were studied. Serum testosterone and the testosterone/sex hormone binding globulin (SHBG) ratio were measured. The testosterone/SHBG ratio (a measure of free (active) testosterone) was significantly reduced in patients treated with prednisolone (p = 0.026), thus showing that glucocorticosteroids reduce free testosterone in male patients. This may be an important cause of glucocorticosteroid-induced osteoporosis, and suggests an additional approach to bone prophylaxis and treatment.