Introduction: The endothelial function has been repeatedly shown to be damaged in rheumatoid arthtritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) patients. However, it is uncertain which of diseases has the greatest influence on endothelial function.

Methods: We studied 60 women with RA (aged 40.47 ± 9.93 years) with disease activity (DAS28) 5.47 ± 0.94, 30 women with SLE (aged 37.33 ± 9.22 years), disease activity index (SLEDAI) 18.40 ± 8.17, organ damage index (SLICC) 1.27 ± 1.53 and 16 women with diffuse cutaneus SSc (aged 47.94 ± 10.46 years). Blood tests included serum lipid profile, glucose and high-sensitivity CRP (hsCRP) measurement. The endothelium-dependent flow-mediated dilatation (FMD) test in a brachial artery was performed by the ultrasound system (Logiq 700, General Electric).

Results: Direct comparison of FMD in RA, SLE and SSc groups has shown that there was overall difference between groups (p = 0.033). This result was confirmed by application of linear models with adjustment for other confounding factors. FMD significantly differed in SSc and RA groups (5.69 ± 5.10 % vs. 8.37 ± 3.84 %; p = 0.021; β = −0.2) as well as in SSc and SLE groups (5.69 ± 5.10 % vs. 9.25 ± 5.15 %; p = 0.021; β = −0.2).

Conclusion: Results of our study have shown that FMD is lower in SSc group as compared to RA and SLE groups, thus the SS does greater damage on endothelial function as compared with RA and SLE.