SUN-LB062 The Impact of Autonomous Cortisol Secretion on Body Composition

Objective: Visceral fat and sarcopenia are two independent factors of increased cardiovascular risk. Limited data exist in performance of these markers in patients with adrenal tumors and autonomous cortisol excretion. Methods: Patients were prospectively enrolled from the adrenal clinics between 2014 and 2018. Inclusion criteria were adults discovered with adrenocortical adenoma on abdominal computed tomography (CT) imaging and diagnosed with nonfunctioning adrenal tumor (NFAT), mild autonomous cortisol excess (MACE) and Cushing syndrome (CS). Exclusion criteria were malignancy, exogenous steroid use, and BMI<18 kg/m(2). MACE was diagnosed based on DST cortisol (cortisol after overnight 1 mg dexamethasone) >1.8 mcg/dl. Age, sex and BMI 1:1 matched healthy controls were recruited from local population. Body composition measurements (visceral adipose tissue [V], subcutaneous adipose tissue [S], visceral/total fat [V/T], and total abdominal muscle mass [M],) were calculated from CT imaging analysis. Results: Of 227 patients with adrenal adenomas, 20 patients were diagnosed with CS, 76 with MACE and 131 with NFAT. Median age of patients was 56 years (range, 18-89), and 67% were women. Median BMI was 31 kg/m(2) (range, 18-58). Median size of the adrenal tumour was 2.4 (range, 0.5-13 cm) and median HU 6 (range, -27 to 36). Adrenalectomy was performed in 52 (23%) patients. Prevalence of hypertension, diabetes mellitus type 2, and obesity was similar among patients with CS, MACE and NFAT, however, higher prevalence of osteoporosis and osteopenia was noted in patients with CS compared to MACE and NFAT ( 55% vs 32% vs 16%, P<0.001). No difference in total fat was found in MACE vs NFAT, however, the proportion of visceral fat (V/T) was higher in MACE (0.43 vs 0.37 in NFAT, P=0.005). After adjusting for age, sex and BMI, both mean M (P=0.03) as well as M to total fat ratio (P=0.02) were independently and inversely correlated with DST cortisol in patients with adrenal adenomas. When compared to age, sex and BMI-matched healthy controls, patients with adenomas demonstrated significant differences in muscle mass (30%, 25% and 20% lower in CS, MACE and NFAT when compared to controls, respectively, P<0.0001 for all). Similarly, V/M ratio was 117%, 77% and 51% higher in CS, MACE and NFAT, respectively, when compared to controls (P<0.0001 for all). Conclusion: DST cortisol is positively correlated with visceral fat and negatively correlated with muscle mass. Patients with adenomas present with lower muscle mass and higher proportion of visceral fat when compared to controls, including patients with so called “nonfunctioning” adenomas. Even a subtle abnormality in cortisol secretion, not detectable by current standard of care testing may play a detrimental role in body composition of patients with adenomas. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.