THU606 Cognitive Impairment In Patients With Mild Autonomous Cortisol Secretion: A Cross-sectional Study

Disclosure: J. Saini: None. R. Nathani: None. S. Singh: None. K. Thangamuthu: None. M. Suresh: None. C. Zhang: None. A.L. Ebbehøj: None. M. Thomas: None. V. Fell: None. E. Atkinson: None. S. Achenbach: None. N. Stricker: None. I. Bancos: None. Introduction: While patients with overt Cushing syndrome are reported to have impaired cognition, the impact of milder, long-standing hypercortisolism on cognition is incompletely characterized. Objective: To determine the impact of MACS on cognition as compared to age, sex, and education-matched referent subjects. Methods: We conducted a single-center cross-sectional study of adults with MACS and referent subjects. MACS was defined as serum cortisol>1.8 mcg/dL after 1 mg dexamethasone suppression test (DST) in patients with adrenal incidentalomas. Referent subjects were included if they had abdominal imaging and had no adrenal disorders. Exclusion criteria were malignancy and exogenous glucocorticoid use within 1 year. All participants underwent a cognitive evaluation using the NIH Toolbox Cognition Battery between 1/2019 to 7/2022. NIH Toolbox assesses 8 cognitive domains using 7 tests and yields 3 composite scores: fluid cognition (executive function, episodic memory, cognitive flexibility, working memory, and processing speed), crystallized cognition (language and vocabulary), and total composite cognition (composite of all). Results are given in fully corrected T scores (adjusted for age, sex, race, and education) with an average of 50 and a standard deviation (SD) of 10. A subgroup analysis was performed based on DST cortisol. The Kruskal-Wallis test was used to compare scores between groups. Results: A total of 94 patients with MACS (median age 57.2 years, IQR 47.8-66.5, 70% women) and 94 referent subjects (median age 58 years, IQR 49.1-66.4, 70% women) were included. The median post-DST cortisol in patients with MACS was 3.3 mcg/dL (IQR, 2.4-6.2). The mean (SD) total composite T-score was lower in patients with MACS vs referent subjects (51 (9.1) vs 56.3 (9.3), P<0.001). Patients with MACS demonstrated lower mean fluid composite T-score when compared to referent subjects (49.5 (10.4) vs 56.9 (9.7), P<0.001). However, mean crystallized composite T-scores were similar in patients with MACS and referent subjects (52.3 (8.1) vs 53.9 (9.6), P=0.342). A subgroup analysis of patients with post-DST cortisol <3 mcg/dL (n=40) vs patients with post-DST cortisol >3 mcg/dL (n=54) did not show any differences in the total, fluid, or crystalized composite scores. Conclusion: Patients with MACS demonstrate lower cognitive performances than a referent group suggesting MACS has a subtle impact on cognitive functioning. The pattern of cognitive impairment in patients with MACS is similar to that seen with normal cognitive aging: impaired fluid cognitions and unaffected crystallized cognition). Cognitive performance did not differ based on the degree of MACS suggesting that in the absence of overt features of hypercortisolism, the degree of MACS is less important than the presence of MACS. Presentation: Thursday, June 15, 2023