Endocrine Abstracts

Background: Cushing’s syndrome (CS) is a relatively unusual condition that resembles many of the phenotypic features of obesity. The 1-mg dexamethasone suppression test (1 mg-DST) is the most frequently used screening tool for CS. However, the lack of suppression after 1-mg DST may be found in obese patients. In the current study, our aim was to evaluate the clinical signs of CS and the 1 mg-DST in obese patients.

Materials and methods: 354 patients (87.9% females, age 37.8±13.4 years) who admitted to our outpatient clinic for obesity enrolled in this study. All the patients were evaluated for the clinical signs of CS. Weight, BMI, waist circumference, blood pressure were recorded. None of the patients used pharmacological glucocorticoid therapy. Lipid parameters, fasting glucose (FPG) and insulin, 75 g OGTT, basal cortisol and ACTH were measured. 1 mg-DST was performed.

Results: The mean weight of the patients was 102.4±20.1 kg, BMI 40±7.35 kg/m² and waist circumference 114.62±14.15 cm. 34.5% of the patients were hypertensive, 46.5% had prediabetes and 12.0.% had type 2 diabetes, 72.6% had dyslipidemia. 36.2% of the patients had central obesity, 72% dorsocervical fat accumulation, 28.8% abdominal striae and 23.2% acne. 49.4% of the women had hirsutism. The mean FPG, insulin levels and HOMA-IR were 112.49±46.59 mg/dl, 12.01±7.16 μU/ml and 3.11±2.03 respectively. The mean cortisol and ACTH levels were as follows: 9.28±3.53 μg/dl and 17.02±10.43 pg/ml. Seven patients failed to suppress plasma cortisol to <1.8 μg/dl. Biochemical confirmation tests were performed in these patients and two of them were diagnosed glucocorticoid-secreting adrenal adenoma.

Conclusions: As a result of our study, 0.5% of the obese patients were diagnosed Cushing’s syndrome and 1.4% of the patients had false-positive 1 mg-DST.