Quantitative assessment of ABCB1 polymorphisms and non-traumatic osteonecrosis of the femur head risk

Several studies have investigated the correlation between genetic polymorphisms in the ABCB1 gene and Non- traumatic osteonecrosis of the femur head (ONFH) risk. However, the potential association is poorly determined due to the small sample size of a single study. Therefore, we carried out a pooled analysis to try to get a definite evaluation of the association. The relevant studies were retrieved in electronic databases PubMed, Google Scholar, and CNKI. The significance of the relationship was determined via the Z test, and P<0.05 was thought statistically significant. Our results suggested that the ABCB1 rs1045642 was significantly related with decreased risk of ONFH under the allelic model (OR=0.69, 95% CI:0.59-0.82, P=0.000), homozygous model (OR=0.44, 95% CI: 0.31-0.64, P=0.000), heterozygous model (OR=0.72, 95% CI: 0.56-0.92, P=0.010), dominant model (OR=0.65, 95% CI: 0.51-0.82, P=0.000), and recessive model (OR=0.46, 95% CI: 0.32-0.67, P=0.000). Similar result was observed for rs2032582 with GC-reduced ONFH under the allelic model (OR= 0.74, 95% CI: 0.56-0.99, P=0.040), and homozygous model (OR=0.46, 95% CI:0.25-0.83, P=0.010). However, no significant association was found between rs1128503 and ONFH susceptibility under the five genetic models analysis. These results indicated that rs1045642 and rs2032582 are protective factors of ONFH, though these findings must be confirmed in a well-designed case-control study with a larger sample size.