It is now clear that subclinical Cushing syndrome is more prevalent than commonly thought, particularly in patients with poorly controlled type 2 diabetes mellitus and obesity. This review highlights the usefulness of late-night salivary cortisol to screen patients with the Cushing phenotype.
Measurement of an elevated late-night salivary cortisol level has a very high sensitivity for even mild Cushing syndrome. Its simplicity makes it the screening test of choice. Furthermore, a suppressed salivary cortisol the morning after low-dose dexamethasone has very high specificity to rule out Cushing syndrome.
Even a moderate suspicion of endogenous hypercortisolism should be investigated, particularly in patients with any of the features of Cushing syndrome. The widespread availability of the tools to measure late-night salivary cortisol now enable the clinician to perform a simple screening test for Cushing syndrome that will lead to effective treatment of the currently undiagnosed.
Endocrinology Research Laboratory, St. Luke’s Medical Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
Correspondence to Hershel Raff, PhD, Endocrinology Research Laboratory, St. Luke’s Medical Center, Department of Medicine, Medical College of Wisconsin, 2801 W. KK River Pkwy., Suite 245, Milwaukee, WI 53215, USA
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