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ACTH following overnight dexamethasone suppression can be used in the verification of autonomous cortisol secretion in patients with adrenal incidentalomas
Author(s) -
Puvaneswaralingam Shobitha,
Kjellbom Albin,
Lindgren Ola,
Löndahl Magnus,
Olsen Henrik
Publication year - 2021
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/cen.14357
Subject(s) - medicine , endocrinology , dexamethasone , hydrocortisone , adrenocorticotropic hormone , basal (medicine) , acth secretion , glucocorticoid , corticosteroid , cortisol awakening response , dexamethasone suppression test , acth receptor , area under the curve , hormone , insulin
Objective During the investigation of adrenal incidentalomas, it is important to accurately diagnose autonomous cortisol secretion (ACS) but the specificity of cortisol ≥50 nmol/L after overnight dexamethasone suppression (cortisol ONDST ) is low. Therefore, ACTH following overnight dexamethasone suppression (ACTH ONDST ) and cortisol following a 2‐day dexamethasone suppression test (cortisol 2‐DAYDST ) were examined as markers of HPA axis suppression during ONDST. Design This cross‐sectional study examined patients with adrenal incidentalomas and basal ACTH ≥ 2.0 pmol/L who underwent ONDST. Measurements ACTH ONDST /ACTH ratio (ACTH ratio) was calculated for all patients. To define cut‐off levels for ACTH ONDST and ACTH ratio as markers of HPA axis suppression, ROC curves were used to separate patients with cortisol ONDST <50 and ≥50 nmol/L. Results Cortisol ONDST was ≥50 nmol/L in 140 out of 373 patients. In patients with cortisol ONDST <50 nmol/L, ACTH ONDST was 0.28 pmol/L (<0.23–2.7). DHEAS was positively correlated to ACTH ONDST , demonstrating a 9% increase with a doubling in ACTH ONDST , p = 0.02. The best cut‐off levels for ACTH ONDST and ACTH ratio to detect cortisol ONDST ≥50 nmol/L were ≥0.6 pmol/L and ≥18% respectively. These cut‐off levels were tested on patients with cortisol ONDST <50 nmol/L, considered to have adequate suppression ( n = 233), and patients with reduction of ≥50 nmol/L from cortisol ONDST to cortisol 2‐DAYDST , who were considered to have inadequate suppression ( n = 16). ACTH ONDST ≥0.6 pmol/L and ACTH ratio ≥18% had a sensitivity of 75% and 81% respectively, and a specificity of 78% and 85% respectively, for detecting patients with inadequate suppression. Conclusions ACTH ONDST and ACTH ratio can be markers of HPA axis suppression in the investigation of adrenal incidentalomas. Cortisol ONDST ≥50 nmol/L with ACTH ONDST <0.6 pmol/L or ACTH ratio <18% should lead to the suspicion of ACS.