Endocrine Abstracts

Background: Cushing’s syndrome (CS) is considered to be more frequent among patients with metabolic syndrome. Previous studies have suggested to perform a routine screening for CS in obese patients; however, more recent reports only recommend a case-finding approach in patients with uncontrolled diabetes and hypertension, despite appropriate treatment.

Objective: The aim of this study was to evaluate the prevalence of unsuspected CS in morbidly obese patients in an outpatient’s clinic.

Design: Retrospective case-note study.

Patients and methods: We reviewed the medical records of morbidly obese patients referred to our clinic prior to bariatric surgery between January 2001 and December 2011. All patients had a complete medical history including physical examination, and 387 (300 females; mean age 46.5±11.2 years; mean BMI 52.8±27.1 kg/m²) underwent screening for CS as part or our pre-surgical protocol. As screening for autonomous cortisol secretion, we performed an overnight 1 mg dexamethasone suppression test (DST). Serum cortisol <1.8 μg/dl was the cut-off point for normal suppression.

Results: In the retrospective analysis, prediabetes and diabetes mellitus were observed in 10.20 and 26.40% respectively. In 20 of 387 patients, screening was considered to be abnormal. Seven of these 20 patients had subsequent normal 24 h urinary free cortisol (UFC) levels (150 μg/24 h). In 13 of 20 patients, we repeated an overnight 1 mg DST, on suspicion of failing to take the dexamethasone correctly. Three patients failed to suppress their cortisol levels, two of them were on carbamazepine, which was considered to be a false positive result. The other patient with abnormal UFC levels was diagnosed with CS (0.26%), whose cause was a pituitary microadenoma.

Conclusion: A low proportion of patients with morbid obesity were found to have CS. Our findings suggest that morbidly obese patients should not be routinely screened for CS.