Endocrine Abstracts

Background: Obesity and diabetes mellitus (DM) are the features of Cushing’s disease (CD). Studies indicated different frequencies of CD among obese, type 2 DM patients. The frequency of CD among obese, type 2 DM have’nt been studied in Turkey. Therefore, we aimed to assess the frequency of CD among obese (BMI>30 kg/m²) type 2 DM patients that had not classical morphological findings of CD.

Patients and methods: Two hundred consecutive obese (BMI>30 kg/m²) type 2 DM patients included into the study (172 female (86%), 28 male (14%), mean age 51.7±8.5). All patients underwent 1 mg low dose dexamethasone supression test (LDDST). Patients with 0800 h cortisole level >1.8 μg/dl underwent further investigation for diagnosis of CD.

Results: LDDST filed to suppress cortisole levels in 19 (9.5%) of 200 patients. After 2 days 2 mg dexamethasone suppression test (DST) cortisole levels suppressed to <1.8 μg/dl in 16 of 19 patients with unsupressed cortisole levels. Patients with suppressed cortisole levels after 2 days 2 mg DST underwent repeat LDDST after 3 months. Cortisole levels suppressed to <1.8 μg/dl in all of these patients with LDSST. With further investigation, CD diagnosed in 3 (1.5%) patients with unsuppressed cortisole levels after 2 days 2 mg DST (2 pituitary CD and one adrenal Cushing).

Conclusion: According to our study results the frequency of CD is higher in type 2 DM patients with BMI>30 kg/m² than in general population. We advise LDDST as screening test in all obese type 2 DM patients.