Association between serum ferritin levels and metabolic syndrome: an updated meta-analysis.

It is definite that the serum iron level has a positive correlation with the risk of obesity. However, the association between increased serum ferritin levels and the metabolic syndrome still remains controversial. The purpose of this meta-analysis is to confirm the association between serum ferritin levels and metabolic syndrome. We searched PubMed and the China National Knowledge Infrastructure (CNKI) for relevant articles that assessed the association between serum ferritin levels and metabolic syndrome and were published between 2006 and 2014. Review Manage 5.3 software was used to collect and analysis the data cited in the ultimately selected papers. The variance was exhibited using the forest plot and the heterogeneity among studies was examined using the I(2) index. We use the funnel plot to evaluate the publication bias. Cross-sectional study, case-control study and prospective cohort study met our inclusion criteria including data from a total of 4,797 participants. The pooled odds ratio (OR) for the metabolic syndrome comparing the highest and lowest category of ferritin levels was 1.20 (95% CI: 0.69, 1.71; I(2)=96%). The meta-analysis demonstrates that elevated ferritin levels are positive aassociated with metabolic syndrome.