Association between PAI-1 4G/5G Polymorphisms and osteonecrosis of femoral head: a meta-analysis

Background: The polymorphism of the plasminogen activator inhibitor-1 (PAI-1) 4 G/5 G gene has been correlated with susceptibility to osteonecrosis of the femoral head (ONFH), but study results are controversial. The aim of this study was to derive a more precise estimation of the relationship between the PAI-1 4 G/5 G Gene polymorphism and ONFH by performing a meta-analysis.

Methods: The meta-analysis was based on five eligible case-control studies involving 419 cases and 969 controls and summarized data indicating the association between PAI-1 polymorphism and risk of osteonecrosis of the femoral head. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to assess the strength of this association in the random-effects model or fixed-effects model.

Results: A significant association between PAI-1 4 G/5 G polymorphism and ONFH susceptibility was observed for 4G4G+4G5G vs. 5G5G (OR=1.766, 95% CI 1.279-2.437, P=0.001), 4 G/4G vs. 4 G/5 G+5G/5 G (OR=2.050, 95% CI 1.581-2.657, P=0.000), 4 G/4G vs. 5 G/5G (OR=2.553, 95% CI 1.345-4.846, P=0.004), and 4 G vs. 5 G (OR=1.758, 95% CI 1.236-2.500, P=0.002). No significant association between PAI-1 4 G/5 G polymorphism and ONFH susceptibility was observed for 4 G/5 G vs. 5 G/5G (OR=1.327, 95% CI 0.939-1.877, P=0.109).

Conclusions: This meta-analysis suggested that 4 G/5 G polymorphism of the PAI-1 gene was a risk factor for ONFH. This study also suggests that the PAI-1 4G4G genotype may indicate a risk for ONFH.

Meta-analysis; Osteonecrosis; Plasminogen activator inhibitor-1; Polymorphism.