Background: Cushing's Syndrome (CS) is associated with excess and premature cardiovascular disease. Endothelial dysfunction is the initiating event in the development of atherosclerosis. Endothelial function is assessed by flow-mediated dilatation (FMD) of brachial artery. The aim of this study was to assess FMD in patients with CS.
Methods: We prospectively evaluated 22 patients with CS (12 women, 10 men; aged 42 +/- 11 years, serum cortisol 28.2 +/- 14 microg/dl, 24-h urinary free cortisol (UFC) 269 +/- 92 microg/day), and 23 control subjects (13 women, 10 men; aged 43 +/- 10 years, serum cortisol 14 +/- 4 microg/dl, 24 h cortisol 60 +/- 22 microg/day). Endothelial function, measured as FMD of the brachial artery using ultrasound, was calculated in two groups. Endothelial function was evaluated by assessing 1-min postischemic FMD of the brachial artery.
Results: FMD was lower in patients with CS than that in those without (11.7 +/- 4.8% vs. 15.8 +/- 3.2%, P = 0.0001, respectively). There was no significant difference between two groups regarding baseline diameter of brachial artery. But, hyperemia diameter was lower in patients with CS than without CS (3.6 +/- 0.22 mm vs. 3.9 +/- 0.19 mm, P = 0.04, respectively).
Conclusion: Endothelium-dependent FMD may impair in patients with CS compared to controls. Measurement of endothelial function may identify high-risk individuals early and therapy to reduce or retard endothelial dysfunction in patients with CS may lead to decreased cardiovascular morbidity and mortality.