Polymorphisms in the gene encoding estrogen receptor alpha are associated with osteoarthritis in Han Chinese women

Polymorphisms in the Xba I and Pvu II restriction enzyme recognition sites in the estrogen receptor-alpha gene (ESR1) have been associated with multiple diseases, including osteoarthritis. To determine whether such polymorphisms are associated with osteoarthritis in a Han Chinese population, 98 women with osteoarthritis and 196 healthy women were genotyped by PCR-RFLP of ESR1 with Xba I and Pvu II. Absence of a restriction polymorphism is indicated as an X or P allele; presence of the restriction polymorphism is indicated as an x or p allele. Clinical information was collected on each participant, including body weight, body mass index (BMI), knee radiograms, and bone mineral density (BMD). Body weight and BMI were higher for each Xba I genotype (all P < 0.05) in individuals with osteoarthritis compared to controls (p < 0.05). Femoral BMD was also significantly higher in the osteoarthritis group (p < 0.05). Additionally, the xx genotype for ESR1 was a significant risk factor for osteoarthritis (OR=1.98, 95% CI: 1.13~4.20, p=0.036). Thus, consistent with findings in other populations, the estrogen receptor genotype xx appears to be associated with susceptibility to osteoarthritis among Han Chinese women.