Association between the Plasminogen Activator Inhibitor-1 4G/5G Gene Polymorphism and Ischemic Stroke; a Meta-Analysis.

The relationship between the insertion/deletion (4G/5G) polymorphism of the plasminogen activator inhibitor type-1 (PAI-1) gene and ischemic stroke (IS), remains unclear. This association has received less attention compared with the relation with coronary heart disease. Since stroke is the third commonest cause of death in the developed world, we performed a meta-analysis of published data regarding this issue. A comprehensive electronic search was carried out up until January 2006 and the analysis was performed using random effects models and meta-regression.

A total of 15 eligible case-control studies were considered. The analysis included 3104 cases and 4870 controls regarding the contrast of 4G/4G vs. the rest genotypes. The 4G pooled allele frequency in cases and controls was 54.21% and 54.75% respectively. Overall, the per-allele Odds Ratio (OR) of the 4G allele was 0.98 with a 95% Confidence Interval (CI) 0.858 to 1.121. As concerns genotypes, we derived non-significant ORs in all contrasts. Our findings do not support a significant association between the 4G/5G polymorphism and cerebrovascular disease under basal conditions. However, the influence of this genotype on the risk of IS in acute disorders might require further investigation, since PAI-1 seems to act as an acute-phase reactant.