Many researchers have suggested that the -174G>C polymorphism in the interleukin-6 (IL-6) promoter region contributes to the risk of obesity; however, this hypothesis is still inconclusive. Therefore, we conducted a meta-analysis to combine the data from several studies to arrive at a conclusion regarding the association between -174G>C polymorphism and the risk of obesity.
The PubMed and Embase databases were searched up to February 20, 2018. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using a random-effects model. Subgroup analysis and sensitivity were also performed.
Ten eligible studies involving 7210 cases were performed to identify the association strength. The association strength was measured by the ORs and 95% CIs. By pooling the eligible studies, we found a significant association between the -174G>C polymorphism and obesity risk (C vs G: OR = 1.37; 95% CI, 1.08–1.74; P heterogeneity < .01). Overall, individuals with the variant CC (OR = 1.58; 95% CI, 1.09–2.28; P heterogeneity < 0.01) and GC/CC (OR = 1.61; 95% CI, 1.13–2.29; P heterogeneity < .01) were associated with a significantly increased risk of obesity.