Dissociation between cortisol and adrenal androgen secretion in patients receiving alternate day prednisone therapy

To evaluate the hypothesis that chronic, low dose, alternate day prednisone treatment may suppress adrenal androgen secretion without causing long term suppression of the hypothalamic-pituitary-adrenal axis we studied seven patients with systemic lupus erythematosus who had been taking low dose (5-20 mg), alternate day prednisone therapy for at least 1 yr. Basal and ovine CRH (oCRH)-stimulated plasma ACTH, cortisol, and adrenal androgen levels were measured 12 h (day on) and 36 h (day off) after the most recent dose of prednisone, and the results were compared to those in seven age- and sex-matched normal subjects. The patients' basal ACTH and cortisol levels did not differ significantly from those in the normal subjects on either the day on or the day off prednisone treatment. By contrast, their basal adrenal androgen levels were significantly decreased compared to those in normal subjects on both the day on and the day off prednisone (P less than 0.05). The patients' oCRH-stimulated ACTH and cortisol levels on the day off prednisone did not differ from normal levels, but were significantly blunted during the day on prednisone (P less than 0.05). In contrast, the patient's oCRH-stimulated adrenal androgen levels were significantly decreased during both the day off and the day on prednisone (P less than 0.05). These findings are consistent with the hypothesis that chronic alternate day prednisone therapy, at doses close to or below replacement, suppresses adrenal androgen levels without long term suppression of the hypothalamic-pituitary-adrenal axis. Based upon these findings, we postulate that an alternate day regimen of prednisone might maintain the benefits while reducing the risks of glucocorticoid therapy of adrenal hyperandrogenism.