Apolipoprotein E gene E2/E2 genotype is a genetic risk factor for vertebral fractures in humans: a large-scale study

Purpose Although many studies have been performed to evaluate whether or not apolipoprotein E gene (APOE) polymorphisms are differentially associated with bone mineral density (BMD) and fractures, the results have been conflicting. This large-scale study was performed to investigate whether a relationship exists between APOE polymorphisms and risk of fracture. Methods A hospital-based case-control study was conducted in 3,000 patients with fractures and 3,000 age- and gender-matched healthy controls. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay was applied to assess the APOE gene polymorphisms. Results Patients with fractures had a significantly higher frequency of APOE E2/E2 genotype [odds ratio (OR)=2.02, 95 % confidence interval (CI)=1.30, 3.14; P=0.002] than healthy controls. When stratifying by fracture type, it was found that patients with vertebral fractures had a significantly higher frequency of APOE E2/E2 genotype (OR=2.86, 95 % CI=1.73, 4.73; P < 0.001). No significant differences were found in nonvertebral (hip or wrist or other) fractures. Conclusions Our study suggests that APOE E2/E2 genotype is a potential genetic risk factor for vertebral fractures in humans.