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 health 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 dilation 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. Short-term estrogen administration can improve endothelial dysfunction in this group of patients.