Quantitative assessment of the influence of TNF-α-308G/A polymorphism on gestational diabetes mellitus risk

Tumor necrosis factor-alpha (TNF-alpha) has been reported to be associated with gestational diabetes mellitus (GDM), but results from previous studies are conflicting. Thus, a meta-analysis was performed to clarify the effects of this polymorphism on GDM risk. Web of Science, Embase, PubMed and CNKI databases were retrieved to determine the eligible TNF-alpha-308G>A polymorphism studies and the susceptibility of the GDM risk. Finally, a total of 7 articles with 465 cases and 589 controls fulfilled the inclusion criteria. The pooled odds ratio (OR) with 95% confidence interval (95% CI) was calculated to examine the associations. Meta-analysis results showed that the TNF-alpha-308G>A polymorphism is associated with a significantly increased risk of GDM (AA vs GG: OR = 5.17, 95% CI 2.78-9.61; GA vs GG: OR = 1.73, 95% CI 1.22-2.45; the dominant model: OR = 2.21, 95% CI 1.37-3.56; the recessive model: OR = 4.26, 95% CI 2.34-7.78). In the subgroup analysis according to the ethnicity, we found that the TNF-alpha-308G>A polymorphism was associated with GDM risk in Asians, but not in other ethnic groups. The present article suggested that the TNF-alpha-308G>A polymorphism is associated with a significantly increased risk of GDM, especially in Asians.