Functional polymorphisms in surfactant protein genes and chronic obstructive pulmonary disease risk: a meta-analysis

Abstract

Aims: Increasing scientific evidence suggests that functional polymorphisms in surfactant protein (SP) genes may contribute to increasing susceptibility to chronic obstructive pulmonary disease (COPD), but many existing studies have yielded inconclusive results. This meta-analysis aims to assess the exact role of SP gene polymorphisms in the development of COPD.

Methods: An extensive literature search for relevant studies was conducted on PubMed, Embase, Web of Science, Cochrane Library, and CBM databases from their inception through May 1st, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratio (OR) with 95% confidence interval (CI) were calculated.

Results: Seven case-control studies were included with a total of 2761 subjects, including 1274 COPD cases and 1482 healthy controls. Our meta-analysis revealed that common polymorphisms in the SP-A gene may be associated with an increased risk of COPD (allele model: OR=1.53, 95% CI: 1.14-2.05, p=0.005; dominant model: OR=1.65, 95% CI: 1.02-2.69, p=0.043; recessive model: OR=1.66, 95% CI: 1.17-2.35, p=0.005; homozygous model: OR=2.06, 95% CI: 1.24-3.41, p=0.005; heterozygous model: OR=1.59, 95% CI: 1.13-2.22, p=0.007), especially among Asian populations. However, there was no evidence for any association between common polymorphisms in the SP-B and SP-D genes and COPD risk (all p>0.05).

Conclusion: The current meta-analysis indicates that common polymorphisms in the SP-A gene may contribute to increasing susceptibility to COPD, especially among Asian populations.