Introduction: Our aim was to study endothelial function in a cohort of systemic lupus erythematosus (SLE) patients prospectively followed at our unit and to investigate its relation with disease activity and damage over time.

Materials and Methods: 38 female SLE patients without overt cardiovascular involvement were enrolled (age 35.8±8ys), followed-up for a mean of 4.45±1.5 years. Clinical history, traditional cardiovascular risk factors, and laboratory parameters were recorded. Active disease was defined as ECLAM global score >2; SLICC/ACR-DI was used for scoring disease damage.FMD was assessed in the brachial artery by high-resolution ultrasound and computerized edge detection system (Quipu s.r.l., Pisa, Italy). FMD assessment was performed at study entry and was repeated in a subgroup of 21 patients at the end of follow-up.

Results: At enrollment, 18 patients presented active disease; mean FMD was 7.9±3.1% with no differences between active (8.7±1) and inactive group (7.9±0.8; p=0.53), even after correction for age and disease duration. Baseline FMD tended to correlate with disease duration (p=0.06), and was similar in the patients with final poor outcome - death (n=3) or damage accrual (n=12) – compared to the others. In the follow-up, FMD showed a significant decline over time (from 8.0±3.2 to 5.9±3.3, P=0.04)while endothelial-independent dilation did not (from 9.2 ±3.5 to 8.6±4.9; p= 0.63). The decline was not different between active and inactive group; however, patients with poor outcome (n=7) showed a greater worsening in FMD over time (−4.1% vs −2.0%).

Conclusions: This study shows that, in SLE patients, disease duration rather than disease activity appears to influence endothelial function. Furthermore, damage accrual is associated with progressive detriment in endothelial function, with preserved response to glyceryl trinitrate.