Low incidence of adrenal insufficiency after transsphenoidal surgery in patients with acromegaly: A long-term follow-up study

Abstract

Context: The long-term prevalence of adrenal insufficiency after transsphenoidal surgery for GH-secreting pituitary adenomas is unknown. However, recently a single study reported a high prevalence of adrenal insufficiency in acromegalic patients after surgical and/or medical treatment without postoperative radiotherapy. Objective: The objective of the study was to assess the prevalence and incidence rates of adrenal insufficiency in consecutive patients during long-term follow-up after successful transsphenoidal surgery for acromegaly. Design: In 91 consecutive patients in remission after transsphenoidal surgery only, we retrospectively reviewed insulin tolerance tests, CRH stimulation tests, metyrapone tests, and ACTH stimulation tests used to assess corticotrope function. Results: Early postoperatively, insufficient adrenal function was observed in 16 patients (18%), whichwastransient in eightandirreversible in eight other patients in the first year of postoperative follow-up. Therefore, after the first year, the prevalence of adrenal insufficiency was 9%. Late, new-onset adrenal insufficiency developed in only three patients 13, 18, and 24 yr after surgery. The incidence rate of late adrenal insufficiency after successful surgery was 2/1000 person-years. After long-term follow-up, a median of 8.1 (1-31 yr), the prevalence of secondary adrenal insufficiency was 12% in patients in remission after surgery for acromegaly. Conclusion: The prevalence of adrenal insufficiency 1 yr after surgery was 9%, whereas during prolonged follow-up, the incidence rate of adrenal insufficiency was only 2/1000 person-years in patients in remission after surgery. Therefore, development of late-onset adrenal insufficiency is a very infrequent complication in patients with acromegaly in remission after transsphenoidal surgery only. Copyright © 2011 by The Endocrine Society.