Department of Cardiology, Second Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou, China .
DNA Cell Biol. 2013 Nov;32(11):654-64. doi: 10.1089/dna.2013.2148. Epub 2013 Sep 17.
Interleukin-6 (IL-6) signaling may play a causal role in the development of coronary heart disease. However, the relationship between IL-6 genotypes and plasma levels of IL-6 appears to be complex. To help clarify the inconsistent findings, we conducted a meta-analysis of the published genetic association studies of the -174 G/C polymorphisms in the IL-6 gene and the circulating IL-6 levels in a normal population. In this meta-analysis, no significant association of IL-6 -174G/C polymorphism and circulating IL-6 levels in a normal population was observed. However, when compared among GG, GC, and CC genotypes, heterogeneity existed among the studies. Sensitivity analysis revealed that, the independent study by Shen et al. influenced the heterogeneity in the homozygous and heterozygous comparison. Although Shen et al.'s study was excluded, no significant association was observed between IL-6 -174G/C polymorphism and circulating IL-6 levels in a normal population [homozygous comparison (GG vs. CC): the pooled standard mean difference (SMD) was -0.01, 95% confidence interval (CI): -0.1-0.08; heterozygous comparison (GC vs. GG or CC): the pooled SMD (GG vs. GC) was -0.05, 95%CI: -0.11-0.01, and the pooled SMD (CC vs. GC) was 0.03, 95%CI: -0.03-0.1]. Under the dominant model, the pooled SMD was -0.05, 95%CI: -0.11-0.01). The meta-analysis provides evidence that the -174G/C polymorphism in the IL-6 gene is not significantly associated with circulating IL-6 levels in a normal population.
白细胞介素 6（IL-6）信号可能在冠心病的发展中起因果作用。然而，IL-6 基因型与循环 IL-6 水平之间的关系似乎很复杂。为了帮助澄清不一致的发现，我们对 IL-6 基因 -174G/C 多态性与正常人群中循环 IL-6 水平的已发表遗传关联研究进行了荟萃分析。在这项荟萃分析中，未观察到 IL-6-174G/C 多态性与正常人群中循环 IL-6 水平之间存在显著关联。然而，在 GG、GC 和 CC 基因型之间进行比较时，研究之间存在异质性。敏感性分析表明，Shen 等人的独立研究影响了同型和杂合比较中的异质性。尽管排除了 Shen 等人的研究，但在正常人群中，IL-6-174G/C 多态性与循环 IL-6 水平之间没有观察到显著关联[同型比较（GG 与 CC）： pooled 标准均数差（SMD）为-0.01，95%置信区间（CI）：-0.1-0.08；杂合比较（GC 与 GG 或 CC）：pooled SMD（GG 与 GC）为-0.05，95%CI：-0.11-0.01，和 pooled SMD（CC 与 GC）为 0.03，95%CI：-0.03-0.1]。在显性模型下，pooled SMD 为-0.05，95%CI：-0.11-0.01）。荟萃分析提供的证据表明，IL-6 基因中的 -174G/C 多态性与正常人群中的循环 IL-6 水平没有显著相关性。
