OBJECTIVE We aimed to examine how different types of adrenal hormone excess influence body composition.

DESIGN A retrospective, cross-sectional, single-centre study.

METHODS We retrospectively enrolled 2971 consecutive adults with adrenal tumours and age-, sex-, and body mass index-matched controls at a 1:3 ratio. The area and attenuation of skeletal muscle and fat at the L3 vertebrae were measured using computed tomography-based analysis software. Prevalence ratios of cardiometabolic outcomes were calculated using the Poisson regression.

RESULTS Patients with non-functioning adenoma (n = 1354) and mild autonomous cortisol secretion (MACS; n = 786) showed similar body compositions. Patients with overt Cushing's syndrome (CS) had the highest visceral fat (VF) area to skeletal muscle area ratio (1.14), while pheochromocytoma (PHEO) patients had the lowest (0.52). Muscle attenuation was lowest in CS and highest in PHEO (32.6 vs 41.5 Hounsfield units, P < .001). Mild autonomous cortisol secretion patients had higher risks of hypertension and dyslipidaemia than non-functioning adenoma patients. Non-functioning adenoma and MACS patients had higher VF area and lower muscle/fat attenuation compared with controls, while primary aldosteronism patients had body compositions similar to controls, except for higher fat attenuation.

CONCLUSIONS Adrenal tumours are associated with altered body composition. Even patients with non-functioning adenoma and MACS had increased VF area and lower muscle and fat attenuation compared with controls, indicating potential cardiometabolic risks.