7122 Obesity is associated with lower basal state cortisol, and diminished cortisol response to the low dose 1ug ACTH: time to depart from the obesity/pseudo-Cushing myth

Disclosure: Y. Sofer: None. E. Osher: None. Y. Greenman: None. K.M. Tordjman: None. G. Shenkerman: None. M. Yaron: None. Y. Marcus-Perlman: None. Y. Moshe: None. S. Shaklai: None. R. Limor: None. S. abiri: None. D. Cantrell: None. N. Stern: None. Objective: Some clinical resemblance may exist between obesity, particularly abdominal obesity, and Cushing’s syndrome. This has stimulated ongoing interest in the role of cortisol's secretion pattern, control and metabolism in obesity. Goals: To compare basal and dynamic cortisol response to an intravenous bolus dose of 1 ug ACTH in healthy obese versus lean controlsDesign: Total, free and salivary cortisol were tested at the basal state and after a standard challenge with 1 ug ACTH in 60 healthy obese subjects (mean BMI= 39 kg/m2) and 54 healthy lean controls (mean BMI=23 kg/m2). Results: Basal total cortisol was significantly lower in obese as compared to lean subjects [361.56+/-132 vs 414+/- 121 nmol/L; p=0.019]. Additionally, baseline total cortisol and salivary cortisol were inversely related to BMI (r=-0.24, r=-0.27; p<0.05 for both). Baseline total and salivery cortisol were also negatively correlated with waist circumference (r=-0.27, r= -0.34; p<0.05 for both). Upon challenge with ACTH, total and salivary cortisol response were significantly lower in obese than in lean subjects [665.16+/-151.8 vs. 728.64+/- 124.2 nmol/L, p<0.05; 31.66 (19-38.64) vs. 40.05 (31.46-46.64) nmol/L, p<0.05]. Conclusion: Basal as well as peak stimulated cortisol and integrated post-1ug ACTH-stimulated total serum cortisol levels were significantly lower in obese subjects. Obesity is not associated with enhanced basal cortisol or ACTH-stimulated cortisol reserve. Hence, increased serum or salivary cortisol is atypical for uncomplicated obesity. Presentation: 6/1/2024