Endothelial dysfunction in systemic lupus erythematosus : an early reversible step towards atherosclerosis

Abstract EN

Background : Endothelial cell (EC) dysfunction, as present in patients with systemic autoimmune disorders, reflects EC activation and when severely and/or chronically impaired results in the development of premature atherosclerosis.

Objective : To assess endothelial function in SLE patients and find out whether any of the specific factors associated with vascular events in SLE influence endothelial dysfunction.

Methodology : The study was conducted on 30 premenopausal SLE females (Group I) and 20 age, sex, weight and height matched premenopausal volunteers as controls (Group II).

Assessment of disease activity was assessed by SLAM score.

All subjects underwent detailed history taking and thorough clinical examination.

Fasting blood sugar, lipoprotein profile and antinuclear, anti–dsDNA and anticardiolipin antibodies were measured.

Vascular function was assessed as carotid intimae media thickness (IMT) and presence of silent a theroma plaques with carotid duplex.

Endothelial function was assessed with high-resolution B-mode Doppler measuring flow-mediated dilation (FMD) in response to reactive hyperemia.

Results : There was significant endothelial dysfunction with reduced FMD (<6%) -which is endothelial dependent- in 76.7% of patients vs.

25% of controls.

There was significantly reduced absolute and percent FMD in patients compared with controls, (0.136±0.152 and 3.87 ± 4.26 vs.

0.330 ± 0.175 and 8.35 ± 4.38 respectively), p < 0.05.

IMT revealed statistically significant difference (0.62 ± 0.13 and 0.551 ± 0.08 respectively) p < 0.05.

Atheroma plaque was detected in carotid arteries in 26.7% of patients vs.

none of controls, statistically significant.

There was no significant difference between patients with and without endothelial dysfunction as regard history of Reynaud’s phenomenon, corticosteroid intake, anticardiolipin antibodies or increased IMT p > 0.05.

There was significant reduction in FMD% in patients with higher disease activity score > 6 than with low score < 6 (7.3 ± 3.34 and 2.83 ± 4.01, p = 0.012).

There was statistically significant negative correlation between FMD % and SLAM score, p > 0.05.

There was statistically significant negative correlation between FMD % and carotid IMT but no statistically significant correlation between FMD % and anticardiolipin antibodies titer p > 0.05.

Conclusions : Systemic lupus erythematosus is an independent risk factor for endothelial dysfunction, that is associated with increased carotid IMT and a theroma plaque especially in higher grades of disease activity.

Interventions to improve endothelial function in SLE may therefore have an impact on the risk of future CHD.