Is there value in routine screening for Cushing's syndrome in patients with diabetes?

Context: Subclinical Cushing’s syndrome has been described among diabetic populations in recent years, but no consensus has emerged about the value of screening. Methods: We enrolled 201 consecutive patients attending our diabetes clinic and 79 controls. Patients with at least two of the following three criteria were offered screening using a 2300 h salivary cortisol test: glycosylated hemoglobin of at least 7%, body mass index of at least 25 kg/m2, and a history of hypertension or blood pressure of at least 140/90 mm Hg. Results are expressed as mean ± sem. Results: Mean nighttime salivary cortisol levels were similar in the two groups (8.5 ± 1.0 nmol/liter for diabetic patients vs. 5.8 ± 1.0 nmol/liter for controls). Forty-seven patients (23%) had a value of at least 10 nmol/liter, which was set as a conservative threshold above which further investigation would be performed. Thirty-five (75%) agreed to further testing with a 1-mg overnight dexamethasone test. Of the remaining 12 patients, 10 were follo...