Association between plasminogen activator inhibitor gene polymorphisms and osteonecrosis of the femoral head susceptibility: A case-control study

This study aimed to analyze the correlation of the plasminogen activator inhibitor (PAI-1) gene polymorphisms (rs6092 and rs7242) with susceptibility of osteonecrosis of the femoral head (ONFH). This case-control study included 106 ONFH patients and 151 healthy controls. PAI-1 polymorphisms were genotyped by polymerase chain reaction (PCR) with direct sequencing. The genotype distribution of polymorphism in the control group was checked with the status of Hardy–Weinberg equilibrium (HWE). The χ(2) test was applied to compare the genotypes of polymorphisms between the case and control groups. The association intensity between PAI-1 polymorphisms and ONFH risk was estimated by odds ratios (ORs) and 95% confidence intervals (95% CI). The linkage disequilibrium of PAI-1 polymorphisms was analyzed by Haploview. We found that the genotypes and alleles of PAI-1 rs6092 and rs7242 polymorphisms had no obvious association with the risk of ONFH (P >.05). But the strong linkage disequilibrium existed between rs6092 and rs7242 polymorphisms and haplotype G-T was significantly associated with the decreased risk of ONFH occurrence (OR = 0.666, 95%CI = 0.445–0.998). PAI-1 rs6092 and rs7242 polymorphisms are not associated with ONFH development, but haplotype G-T may be a protective factor of ONFH.