Endocrine Abstracts

Cushing disease (CD) is a rare affection due to an ACTH secreting pituitary adenoma with a hypercorticism as main consequence.

The aim of this study was to assess glucose tolerance anomalies in CD.

Patients: Twenty-one patients with a diagnosed CD were included; The majority of them (77.3%; n=17) were female. Mean age was 34.2 (19–54 years) and mean BMI 31.9 kg/m² (25.9–43.7). Mean progression period of CD was 21.8 months (5–72).

Catabolic signs and hypertension were present in respectively 85.7% (n=18) and 68% (n=15) of cases. Mean average of basal plasmatic cortisol, cortisol after low-dose dexamethasone-suppressing test and basal ACTH were respectively 851 nmol/l (287–2373), 529 nmol/l (169–1515 nmol/l), and 119 pg/ml (59–328). Pituitary lesion on MRI was a microadenoma (diameter <1 cm) in 54.4% of cases (n=12) and a macroadenoma in the other cases.

Results: A pre-existing diabetes was present in 8 patients with a mean HBA1C at 11.4% (10.8–12%). In the other patients, fasting plasma glucose and OGTT were performed and reveled five cases of normal glucose tolerance, four of pre-diabetes, and four of diabetes.

Comparative study between patients having normal glucose tolerance (n=5) and those with pre-diabetes or diabetes (n=16) showed that patients having glucose tolerance anomalies had a higher age (36.5 vs 26.8 years, P=0.047) and more frequent catabolic signs (16/16 vs 2/5; P=0.008) than patients without glucose anomalies. No other correlation was found between glucose tolerance and clinical, biological or radiological features.

Conclusion: Glucose tolerance anomalies are common in CD. These anomalies seem to be positively correlated to the age and to the presence of catabolic signs.