Association of Adrenergic Receptor α2A (α2A-AR) Gene rs1800544 Polymorphism with Bone Mineral Density and Bone Turnover Markers in an Elderly Chinese Population

Background: Adrenergic receptor alpha 2A (alpha 2A-AR) is up-regulated in osteoporotic bone osteoblasts. Previous research demonstrated an association between polymorphism of alpha 2A-AR gene and bone mineral density (BMD) as well as bone turnover markers (BTMs) in the Slovenian population. The present study aimed to investigate the association of rs1800544 polymorphism of alpha 2A-AR gene with BMD and BTMs in the Chinese elderly population with osteoporosis (OP) or with osteoporotic fractures. Material/Methods: A total of 346 unrelated elderly individuals were recruited in the study. Rs1800544 polymorphism was determined by Snapshot technology. BTMs were determined by electrochemiluminescence. BMDs at lumbar spine (LS) and proximal femur were measured with dual-energy X-ray absorptiometry (DEXA). Hardy-Weinberg equilibrium and distribution of genotype frequencies were verified using the chi-squared test. Analysis of co-variance (ANCOVA) adjusted for confounding factors was performed to explore the relationship of rs1800544 polymorphism with BMD and BTMs in all participants and in subgroups. Results: The genotype distributions in all subjects and in subgroups conformed to Hardy-Weinberg equilibrium (P>0.1). Distribution of genotype frequencies of subgroups showed no significant differences (P>0.05). Patients with GG genotype in the fracture group had significantly higher serum BTMs level compared with those carrying other genotypes (P<0.05). No significant association between rs1800544 and BTMs was detected in the elderly population with OP. Comparison of BMD at each site in all participants did not show any significant difference in subgroups with CC, CG, and GG genotypes (P>0.05). Conclusions: Rs1800544 polymorphism is associated with BTMs level in Chinese elderly individuals with osteoporotic fractures, indicating the involvement of genetic variation of alpha 2A-AR gene in bone metabolism.