The adipose visceral dysfunction plays an important role in diabetes in Cushing disease.

Abstract

Background: Cushing disease (CD) is associated with increased morbidity and mortality caused by cardiometabolic alterations. Visceral Adiposity Index (VAI) expresses impaired adipose distribution and function which are related to the cardiometabolic risk. Aim: To evaluate in a cohort of CD patients the correlation between VAI and other parameters, such as gender, etiology, age, cortisol values measured in the morning (8 am) and at the midnight, urinary free cortisol (24h sample of urine, average of three samples) and glucose tolerance as normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), IFG+IGT and diabetes mellitus. Materials and methods: We performed a retrospective study in 140 CD patients consecutively afferent in outpatients clinic of the Universities of Naples and Palermo. Patients were divided by VAI tertiles and trend analysis was evaluated. Results: 27 men and 113 women, mean age of 40.98±16,61 years and BMI of 30.86 ± 6.01 Kg/m2 were studied. 62.7% of patients had a metabolic syndrome, 30.7% diabetes mellitus, 5.7% IFG, 12.1% IGT and 0.7% IFG+IGT. Among all parameters evaluated, only the midnight cortisol showed a significant increasing trend according to VAI tertiles (I tertile 172.57±77.24, II tertile 168.40±73.67, III tertile 227.06±119.42; p=0.045). Significant correlations between HOMA IR increase and VAI tertiles (I tertile 2.16±1.18, II tertile 3.13±1.49, III tertile 2.81±1.37 p=0.020), HbA1c increase and VAI tertiles (I tertile 5.87±0.84%, II tertile 6.40±1.23%, III tertile 6.60±1.19% p=0.018) were found. No significant trend for HOMA-b was observed. Conclusions: CD women have a higher cardiometabolic risk than men and this risk becomes more higher more older is the patient. Therefore these patients have a condition of visceral adiposity dysfunction that contributes to decrease of insulin sensitivity, but not at a reduction in betacell function, like the typical diabetes mellitus at onset. Thus, visceral fat dysfunction seems to be a key factor not only in favouring diabetes mellitus onset but also in worsening glycaemic control in Cushing diabetic patients.