The impact of statins therapy on disease activity and inflammatory factor in patients with rheumatoid arthritis: a meta-analysis.

Objectives: Statin is the most widely used as HMG-CoA reductase inhibitor, and contributes to clinically significant vascular risk reduction. However, the role of statins in the rheumatoid arthritis (RA) immunomodulation is debatable. This meta-analysis aimed to determine the efficacy of statins therapy in RA patients.

Methods: A structured literature search was undertaken to identify randomised controlled trials (RCTs) conducted in RA patients receiving either statins or control. A meta-analysis on standardised mean difference (SMD) with a 95% confidence interval (95%CI) was conducted.

Results: We included 15 studies with a total of 992 patients (487 patients allocated to statins therapy). Our data revealed statins can attenuate disease activity markedly. Overall, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) declined significantly during the treatment (n=12, SMD: -2.222, 95%CI: -2.404, -2.040, p=0.000; n=14, SMD: -3.014, 95%CI: -3.207, -2.821, p=0.000), among which ESR and CRP decreased obviously at 12 months (n=5, SMD: -2.874, 95%CI: -3.224, -2.523, p=0.000; n=7, SMD: -3.970, 95%CI: -4.300, -3.641, p=0.000; respectively). As expected, the tender joint count (TJC) and swollen joint count (SJC) also fell (n=9, SMD: -2.005, 95% CI: -2.216, -1.794; p=0.000; n=10, SMD: -1.76, 95%CI: -1.948, -1.577; p=0.000; respectively). Besides, morning stiffness was attenuated (n=5, SMD: -1.242, 95%CI: -1.474, -1.011, p=0.000), and showed no significant differences between 12 months and 24 months (p=0.205). Notably, statins indeed potently down-regulate inflammatory factors TNF-α (n=7, SMD: -4.290, 95%CI: -4.659, -3.922; p=0.000), IL-1 (n=4, SMD: -1.324, 95%CI: -1.646, -1.003; p=0.000), and IL-6 (n=10, SMD: -1.652, 95%CI: -1.822, -1.482; p=0.000). No publication bias was observed across all studies based on the Begg and Egger test.

Conclusions: This meta-analysis demonstrates the pleiotropic effects of statins on ameliorating RA activity and mediating clinically apparent anti-inflammatory effects in the context of RA autoimmune inflammation, which make it recommended as a potent treatment for RA patients.