Short-term estrogen administration improves abnormal endothelial function in women with systemic sclerosis and Raynaud's phenomenon

Background Morphologic changes of the vascular endothelium are common in patients with systemic sclerosis and Raynaud's phenomenon. The aim of this study was to evaluate the endothelium-dependent vasodilatation and endothelium-independent vasodilatation and to examine the effects of short-term estrogen administration on vascular responses in these patients. Methods and Results The study included 12 female patients with systemic sclerosis and Raynaud's phenomenon (aged 49 +/- 14 years) and 12 age- and sex-matched healthy control subjects. With the use of high-resolution ultrasound imaging, brachial artery diameter was measured at rest, during reactive hyperemia (endothelium-dependent response), and after administration of sublingual nitroglycerin (endothelium-independent dilatation). Intima-media thickness of the common carotid artery was also measured. Baseline diameter was similar in patients and control subjects; intima-media thickness was significantly higher in patients (0.83 +/- 0.3 vs 0.46 +/- 0.2 mm, P = .002) than in control subjects. Flow-mediated dilatation was reduced in patients (3.6% +/- 7% vs 11.9% +/- 4.6%, P = .003); endothelium-independent dilatation also was reduced in patients with Raynaud's phenomenon (14% +/- 7% vs 23% +/- 6%, P = .003). Vascular responses in 10 patients were examined 15 minutes after administration of conjugated estrogens (25 mg intravenously); there was a significant increase of endothelium-dependent dilatation after estrogen administration (1.7% +/- 4% to 6.3% +/- 4%, P = .01), whereas endothelium-independent dilatation did not change (13.4% +/- 8% to 15.5% +/- 7%, not significant). Conclusions Endothelium-dependent vasodilatation and endothelium-independent vasodilatation are impaired in patients with Raynaud's phenomenon secondary to systemic sclerosis, whereas intima-media thickness is increased. Shortterm estrogen administration can improve endothelial dysfunction in this group of patients.