Impact of hypercortisolism on skeletal muscle mass and adipose tissue mass in patients with adrenal adenomas

Context: Abdominal visceral adiposity and central sarcopenia are markers of increased cardiovascular risk and mortality. Objective: To assess whether central sarcopenia and adiposity can serve as a marker of disease severity in patients with adrenal adenomas and glucocorticoid secretory autonomy. Design: Retrospective cohort study. Patients: Twenty-five patients with overt Cushing's syndrome (CS), 48 patients with mild autonomous cortisol excess (MACE) and 32 patients with a nonfunctioning adrenal tumour (NFAT) were included. Methods: Medical records were reviewed, and body composition measurements (visceral fat [VAT], subcutaneous fat [SAT], visceral/total fat [V/T], visceral/subcutaneous [V/S] and total abdominal muscle mass) were calculated based on abdominal computed tomography (CT). Results: In patients with overt CS, when compared to patients with NFAT, the V/T fat and the V/S ratio were increased by 0.08 (P < .001) and by 0.3 (P < .001); however, these measurements were decreased by 0.04 (P = .007) and 0.2 (P = .01), respectively, in patients with MACE. Total muscle mass was decreased by -10 cm(2) (P = .02) in patients with overt CS compared to patients with NFAT. Correlation with morning serum cortisol concentrations after dexamethasone suppression testing revealed that for every 28 nmol/L cortisol increase there was a 0.008 increase in V/T (P < .001), 0.02 increase in the V/S fat ratio (P < .001) and a 1.2 cm(2) decrease in mean total muscle mass (P = .002). Conclusions: The severity of hypercortisolism was correlated with lower muscle mass and higher visceral adiposity. These CT-based markers may allow for a more reliable and objective assessment of glucocorticoid-related disease severity in patients with adrenal adenomas.