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

BackgroundThe polymorphism of the plasminogen activator inhibitor-1 (PAI-1) 4G/5G 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 4G/5G Gene polymorphism and ONFH by performing a meta-analysis.MethodsThe 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.ResultsA significant association between PAI-1 4G/5G polymorphism and ONFH susceptibility was observed for 4G4G + 4G5G vs. 5G5G (OR = 1.766, 95% CI 1.279-2.437, P = 0.001), 4G/4G vs. 4G/5G + 5G/5G (OR = 2.050, 95% CI 1.581-2.657, P = 0.000), 4G/4G vs. 5G/5G (OR = 2.553, 95% CI 1.345-4.846, P = 0.004), and 4G vs. 5G (OR = 1.758, 95% CI 1.236-2.500, P = 0.002). No significant association between PAI-1 4G/5G polymorphism and ONFH susceptibility was observed for 4G/5G vs. 5G/5G (OR = 1.327, 95% CI 0.939-1.877, P = 0.109).ConclusionsThis meta-analysis suggested that 4G/5G 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.