Suppression and recovery of adrenal response after short-term, high-dose glucocorticoid treatment

Background Suppression of the adrenal response is an unpredictable conseque nce of glucocorticoid treatment. To investigate the kinetics of the adrenal response after shortterm, high-dose glucocorticoid treatment, we measured the adrenal response to the low-dose (1 mu g) corticotropin stimulation tes t. Methods We studied 75 patients who received the equivalent of at least 25 m g prednisone daily for between 5 days and 30 days. After discontinuation of glucocorticoid treatment, 1 mu g corticotropin was administered intravenou sly, and stimulated plasma cortisol concentrations were measured 30 min lat er. In patients with a suppressed response to 1 mu g corticotropin, the tes t was repeated until stimulated plasma cortisol concentrations reached the normal range. Findings The adrenal response to 1 mu g corticotropin was suppressed in 34 patients and normal in 41. Subsequent low-dose corticotropin tests showed a steady recovery of the adrenal response within 14 days. In two patients, t he adrenal response remained suppressed for several months. There was no co rrelation between plasma cortisol concentrations and the duration or dose o f glucocorticoid treatment. Interpretation Suppression of the adrenal response is common after short-te rm, high-dose glucocorticoid treatment. The low-dose corticotropin test is a sensitive and simple test to assess the adrenal response after such treat ment.