Impaired endothelial vasoregulatory function in patients with systemic lupus erythematosus: association with renal involvement, inflammatory markers, and autoantibodies

Abstract

Background. The leading cause of death in patients with systemic lupus erythematosus (SLE) is cardiovascular diseases due to early atherosclerosis. Endothelial dysfunction is considered one of the markers of subclinical atherosclerosis. The work aimed at assessing the endothelial vasoregulatory function in patients with SLE and its relationship with clinical and laboratory features of SLE. Materials and methods. We studied endothelium-dependent (EDVD) and endothelium-independent vasodilation (EIVD) of the brachial artery in 100 patients with SLE. Results. EDVD in patients with SLE was reduced by an average of 31.5 % compared with healthy individuals (p < 0.001). The average va­lues of EIVD in the group of patients with SLE (20.03 ± 0.80 %) and in the group of healthy individuals (21.4 ± 0.7 %) did not significantly differ (p > 0.05). The presence of lupus nephritis was associated with a significant deterioration in EDVD (42.5 % compared with the control group and 25.8 % compared with the alternative group, p < 0.001 and p < 0.05, respectively). The ave­rage values of EDVD in patients with elevated levels of C-reactive protein (CRP) were reduced by 35.1 % compared with the control group (p < 0.001), and in patients with normal levels of CRP — by 25.9 % (p < 0.001; the difference between the subgroups is unreliable). No significant correlation between the values of CRP and EDVD was found (r = 0.10, p > 0.05). In patients with positive antinuclear factor (ANF) and antibodies to native DNA (anti-nDNA), the values of EDVD were 32.0 and 35.2 % lower, respectively, than in the control group (p < 0.001). At the same time, in patients with negative ANF and anti-nDNA, the difference with the control group was unreliable (p > 0.05). According to the results of multiple linear regression analysis, the independent determinants of EDVD were the patient’s age (p < 0.001), the pre­sence of nephritis (regardless of its form) (p = 0.001), polyarthritis (p = 0.019), and Raynaud’s syndrome (p = 0.045). Conclusions. SLE patients have impaired vasoregulatory function of the endothelium, especially in the presence of lupus nephritis, elevated titers of ANF and anti-nDNA. EDVD does not correlate with CRP level in patients with SLE.