Statins influence biomarkers of low grade inflammation in apparently healthy people or patients with chronic diseases: A systematic review and meta-analysis of randomized clinical trials

Abstract

Background: No earlier study summarized findings on the effect of statins on inflammatory biomarkers in apparently healthy individuals or those with chronic diseases. This study was done to systematically review earlier publications on the effect of statins on serum concentrations of C-reactive protein (CRP) and Interleukin-6 (IL-6) in apparently healthy individuals or those with chronic diseases. Methods: We searched relevant publications published up to December 2018 in PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar databases. For this purpose, suitable MESH and non-MESH keywords were used. Randomized placebo-controlled clinical trials that examined the effect of statins on serum concentrations of CRP and IL-6 in apparently healthy adults or those with chronic diseases were included. Results: Overall, 18 studies with 23 effect sizes, that enrolled 32,156 individuals (38 female and 62 male; mean age: 44.79 years) were included. When we combined 21 effect sizes from 16 studies, we observed a significant reduction in circulating levels of CRP following administration of statins Weighted Mean Difference (WMD): 0.80; 95% CI: 1.05, 0.56. Combining 12 effect sizes from 11 studies, a significant reduction was found in serum CRP concentrations following administration of Atorvastatin (WMD: 0.57; 95% CI: 0.78, 0.35). Pooling 5 effect sizes from 2 studies, we found a significant reduction in serum concentrations of CRP following administration of Simvastatin (WMD: 0.29; 95% CI: 0.49, 0.10; I-2 = 88.5%). Combining 6 effect sizes from 5 studies, we found a significant reduction in serum IL-6 concentrations after Atorvastatin therapy (WMD: 2.13; 95% CI: 3.96, 0.30; I-2 = 98.6%). Conclusions: In conclusion, we found that statins administration in apparently healthy people or those with chronic diseases help reducing serum CRP concentrations. In addition, Atorvastatin administration resulted in reduced serum IL-6 concentrations in these people.