ASSESSMENT OF VASCULAR FUNCTION IN SYSTEMIC SCLEROSIS: ENDOTHELIUM-DEPENDENT FLOW-MEDIATED AND ENDOTHELIUM-INDEPENDENT FUNCTIONS

Background: One of the major factors in the pathology of systemic sclerosis (SSc) is functional and structural vasculopathy with endothelial dysfunction.Objectives: To investigate the endothelium-dependent flow-mediated (FMD), endothelium-independent (nitroglycerin-induced) dilatation (NMD) of the brachial artery and intima-media thickness (IMT) of the elastic carotid artery in SSc patients compared to healthy controls.Methods: Endothelium-dependent flow-mediated and endothelium-independent (nitroglycerin-induced) dilatation of the brachial artery was measured as the percentage of change from baseline (FMD% and NMD%) in 29 SSc patients and 29 age- and sex-matched healthy controls parallel with IMT measurements by high-resolution ultrasound imaging. Correlations between FMD, NMD, IMT and the age, scleroderma subtype (diffuse or limited form), anti-Scl70, anti-centromer (ACA) and antiphospholipid antibody (AP) positivity were assessed.Results: In the 29 SSc patients (mean age 51.79±10.04 years) the FMD was 4.82±3.75% which was significantly decreased compared to controls (8.86±3.55%, p < 0.001). Some difference was found in IMT (p=0.067) and no difference was found in NMD% between SSc patients and controls. There was a significant, positive correlation between IMT and age in SSc (r=0.470, p=0.013), also in healthy controls (r=0.61, p=0.003), but no correlation was found between FMD and age. NMD showed negative correlation with age but only in SSc patients. We did not find any correlation between measured vascular parameters and the subtype of scleroderma or anti-Scl70, ACA and AP antibodies.Conclusion: Endothelium-dependent flow-mediated dilatation of the brachial artery is impaired in SSc patients suggesting endothelial dysfunction in this disease. At the same time, the endothelium-independent (nitroglycerin-induced) dilatation of the brachial artery remains to be preserved in SSc. Thus, vascular symptoms of SSc patients may be improved using nitroglycerin.Citation: Ann Rheum Dis, volume 65, supplement II, year 2006, page 525Session: Scleroderma and related syndromes