Interleukin-6 and Diabetic Retinopathy: A Systematic Review and Meta-Analysis

ABSTRACTBackground: Interleukin-6 (IL-6) is produced by a variety of cells involved in inflammation and acts as local intensification signals in pathological processes associated with chronic eye inflammation. This meta-analysis was performed to provide a better understanding of the relationship between IL-6 and diabetic retinopathy.Methods: The study was started with systematic search for literatures by using the PubMed, Web of Science and Embase online databases. The standard mean difference (SMD) and its 95% confidence intervals (CIs) were was included and then pooled with a random effects model.Results: Thirty-one articles, containing1099 DR patients and 1010 controls, were included in this meta-analysis. The level of IL-6 in the DR group was found to be higher than that in the control group (SMD: 2.12, 95% CI: 1.53−2.70, p < 0.00001).Obvious heterogeneity existed between the studies (p < 0.00001, I2 = 96%). So a subgroup analysis and sensitivity analysis were performed. Removing the sensitivity studi...