Association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and risk of Alzheimer's disease, metabolic syndrome, and female infertility: A meta-analysis

Background Plasminogen activator inhibitor-1 (PAI-1) is considered to be involved in the physiopathological mechanisms of Alzheimer's disease (AD), metabolic syndrome (MetS), and female infertility. Previous studies investigating the association between PAI-14G/5G (rs1799889) gene polymorphism and the risk of AD, MetS, and female infertility have reported inconsistent results. The aim of the present study was to investigate possible associations. Methods Eligible studies were retrieved through PubMed, Medline, EMBASE, CNKI, and WANFANG databases. The odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the associations. Subgroup analyses by ethnicity and mean age, sensitivity analyses, and publication bias were performed. Results Five studies (four articles) for AD, six studies (six articles) for MetS, and four studies (four articles) for female infertility were included in this meta-analysis. Our results showed no significant associations between the PAI-14G/5G polymorphism and the risk of AD and female infertility in five genetic models. For the risk of MetS, the PAI-1 4G/5G (rs1799889) polymorphism may be associated with the risk of MetS (4G vs 5G, OR = 1.31, 95%CI = 1.04-1.64, P = .021), especially in Asians (4G/4G vs 4G/5G+5G/5G, OR = 1.38, 95%CI = 1.01-1.87, P = .041) and patients with mean age > 50 years old (4G/4G vs 4G/5G+5G/5G, OR = 1.36, 95%CI = 1.03-1.78, P = .029). Conclusion The present meta-analysis suggested that the PAI-1 4G/5G polymorphism might be associated with the risk of MetS, but no evidence was detected for AD and female infertility.