Clinical assessment of endothelial function in patients with rheumatoid arthritis: A meta-analysis of literature studies

Background Several studies reported an increased cardiovascular (CV) morbidity and mortality in patients with rheumatoid arthritis (RA). Flow-mediated (FMD) and nitrate-mediated dilation (NMD) are considered non-invasive methods to assess endothelial function and surrogate markers of subclinical atherosclerosis. Methods We performed a systematic review with meta-analysis and meta-regression of literature studies evaluating the impact of RA on FMD and NMD. Studies evaluating the relationship between RA and markers of CV risk (FMD and NMD) were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. The random-effect method was used for analyses and results were expressed as mean difference (MD). Results A total of 20 studies (852 RA patients, 836 controls) were included in the final analysis. In detail, 20 studies with data on FMD (852 cases, 836 controls) and 5 studies with data on NMD (207 cases, 147 controls) were analyzed. Compared to controls, RA patients showed a significantly lower FMD (MD: - 2.16%; 95% CI: - 3.33, - 0.98; P = 0.0003), with no differences in NMD (MD: - 0.41%; 95% CI: - 2.89, 2.06; P = 0.74). Interestingly, a lower FMD (MD: - 2.00%; 95% CI: - 3.20, - 0.80; P = 0.001) and no differences in NMD (P = 0.49) were confirmed when excluding data on patients with early-RA. Meta-regression models showed that a more severe inflammatory status was associated with a more significant impairment in FMD. Conclusions RA patients show impaired FMD, which is currently considered an independent predictor of CV events. The presence of endothelial dysfunction in RA should be taken into account to plan adequate prevention strategies and therapeutic approaches.