An Updated Meta-Analysis of the Association between Tumor Necrosis Factor-α-308G/A Polymorphism and Obstructive Sleep Apnea-Hypopnea Syndrome

Background: Several studies have reported that the tumor necrosis factor-alpha (TNF-alpha) -308G/A polymorphism is associated with susceptibility to obstructive sleep apnea-hypopnea syndrome (OSAHS). However, these results are controversial and conflicting. Objective: To evaluate the association between TNF-alpha-308G/A and OSAHS risk by meta-analysis. Methods: Electronic databases, including PubMed, Embase, China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu, were searched to identify relevant studies. Data were extracted from the included studies. A model-free approach using odds ratio (OR), generalized odds ratio (ORG) and 95% confidence interval (CI) of the allele contrast to assess the association between the -308G/A polymorphism and OSAHS risk. Cumulative and recursive cumulative meta-analyses (CMA) were also carried out to investigate the trend and stability of effect sizes as evidence accumulated. Results: Seven studies including 1369 OSAHS patients and 1064 controls were identified in this meta-analysis. Significant associations were derived from the variants of the allele contrast [(OR, 1.78; 95% CI, 1.45-2.18) or (ORG, 2.01; 95% CI, 1.27-3.19). CMA showed a trend of an association. Recursive CMA indicated that more evidence is needed to conclude on the status of significance. No significant publication bias was found. Conclusions: Our meta-analysis suggested that the TNF-alpha-308G/A polymorphism contribute to the risk of OSAHS. Further studies with larger sample should be performed to confirm our findings.