Assessment of aortic perivascular and renal sinus fat in endogenous cortisol excess of different etiology.

Objective: Endogenous cortisol excess is known to affect body fat distribution. Ectopic fat is the accumulation of triglycerides in non-adipose tissue regions that normally contain little fat. The aim of study was to investigate the amount of ectopic fat in aortic perivascular and renal sinus fat of patients with endogenous cortisol excess and its relationship with their comorbitidies and laboratory findings.

Design: A total of 119 patients, including 16 patients with pituitary Cushing's disease (CD), 21 patients with adrenal Cushing's syndrome (CS), 34 patients with mild autonomous cortisol secretion (MACS), and 48 patients with nonfunctioning adrenal adenomas were enrolled in this retrospective study. Aortic perivascular fat and renal sinus fat were evaluated with magnetic resonance imaging.

Results: It was determined that the amount of aortic perivascular fat was increased in patients with CD (P = 0.01). The linear regression analysis showed that the amount of perivascular fat was associated with triglyceride levels and cortisol levels after the 1 mg dexamethasone suppression test as well as with gender (P < 0.01). Renal sinus fat measurements were similar in the groups (P > 0.05). After adjusting for age, sex, and BMI, perivascular fat was found to be higher in pituitary the CD than in the MACS and the nonfunctioning adenoma groups, and renal sinus fat was seen to be higher in pituitary the CD than in the MACS groups (P < 0.05). Patients with diabetes mellitus had an increased amount of renal sinus fat (P = 0.008).

Conclusion: The amount of perivascular and renal sinus fat may increase in patients with CD. Further studies are needed to elucidate ectopic fat distribution in patients with endogenous cortisol excess.