Suppressed ACTH Is Frequently Unrelated to Autonomous Cortisol Secretion in Patients With Adrenal Incidentalomas

Abstract

This study identifies a previously unrecognized group of patients defined by suppressed ACTH despite normal cortisolONDST. This suppression of ACTH by a factor other than ACS may explain the limitation of suppressed ACTH as a marker for ACS. We suggest increased cortisol secretion in response to ACTH by the AI to be an additional factor.