Demystifying “Steroid Withdrawal” During Remission in Cushing's Disease: Is Mineralocorticoid Replacement the Answer?

OBJECTIVE: To study renin-angiotensin-aldosterone axis status (RAAS) in patients of Cushing's disease (CD) at baseline and 6 weeks after curative trans-sphenoidal surgery and evaluate the role of mineralocorticoid replacement in the resolution of “steroid withdrawal syndrome” (SWS). Postoperative RAAS status had not been evaluated in previous studies, although aldosterone levels have been shown to be suppressed during medical therapy with pasireotide and cabergoline. MATERIALS AND METHODS: This was a prospective, single-center study. Patients with CD, aged between 15–75 years, undergoing curative pituitary surgery were recruited. An 8 am and 11 pm cortisol and adrenocorticotropic hormone (ACTH) were measured at baseline. An 8 am cortisol was measured 6 weeks after surgery to demonstrate remission. Plasma-renin activity and plasma-aldosterone concentration were measured at baseline and 6 weeks after curative surgery. RESULTS: A total of 14 patients (11 female, 3 male) were recruited initially, of these 8 patients completed the study. The plasma-renin activity was not suppressed at baseline and did not rise significantly after surgery (P = 0.717). However, plasma-aldosterone concentration was in the low-normal range at baseline and had risen significantly 6 weeks after surgery (P = 0.013). No difference was noted in subgroups with or without hypertension. CONCLUSION: Curative pituitary surgery leads to normalization of plasma-aldosterone concentration in patients with CD just 6 weeks after surgery. Hence, mineralocorticoid replacement may not prove beneficial in alleviating the “SWS” in postsurgical CD patients who have achieved remission.