Relation of metabolic syndrome and its components with risk of diabetic retinopathy: A meta-analysis of observational studies

Emerging studies have reported the effects of metabolic syndrome (MetS) and its components on risk of diabetic retinopathy (DR), but the results remain controversial. Therefore, we performed a meta-analysis to evaluate the relationship between MetS and risk of DR. A meta-analysis of observational studies. Studies were searched from PubMed, Cochrane Library, and Elsevier databases from the start of the database up until November 30, 2017. Adjusted odds ratios (ORs) and its corresponding 95% confidence intervals (CIs) were extracted and pooled by using a random effects model. A total of 12 observational studies were included in this meta-analysis. When the MetS as a full syndrome, MetS was not associated with increased risks of type 1 (OR = 1.47, 95% CI 0.67–3.24; P = .34) or type 2 (OR = 1.34, 95% CI 0.91–1.98; P = .14) DR. In addition, none of single component of MetS was associated with the risk of DR, including body mass index/waist circumference (BMI/WC) (OR = 0.92, 95% CI 0.75–1.13; P = .41), blood pressure (OR = 1.37, 95% CI 0.96–1.95; P = .08), high density lipoprotein (OR = 0.97, 95% CI 0.93–1.01; P = .19), and triglyceride (OR = 0.85, 95% CI 0.63–1.15; P = .29). In the sensitivity analysis, the pooled OR values were not changed after we removed the included studies one by one. Based on recent published data, neither MetS nor its components are associated with an increased risk of DR.