ASSOCIATIONS OF OSTEOPOROSIS AND OSTEOPROTEGERIN GENE: A STUDY OF 135 PATIENTS

Osteoprotegerin gene (OPG) is an important candidate gene of osteoporosis. The aim of this study was to determine if two polymorphisms in the OPG gene influ- ence bone turnover markers and bone mineral density (BMD). A total of 135 patients, aged 41 to 87 years, were included in the study. Lumbar spine, femoral neck, total-hip and distal radius BMD were measured by dual-energy X-ray absorp- tiometry (DXA) and bone turnover markers were measured by standard biochem- ical procedures. OPG gene polymorphisms A163>G and T245>G were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The frequencies of A163>G and T245>G polymorphisms in the OPG gene were determined by screening 131 DNA samples. The prevalence of genotypes of the A163G polymorphism was 59, 4% for GG, 33, 3% for AG and 7, 2% for AA geno- type in group with osteoporosis, whereas in control group the prevalence was 77, 8%, 16, 7% and 5, 6%, respectively. The prevalence of genotypes of the T245G polymorphism was 88, 4% for genotype TT and 11, 6% for genotype TG in group with osteoporosis, whereas in control group the prevalence was 94, 4% and 5, 6%, respectively. Analysis of BMD in the distal radius of postmenopausal women showed a trend to lower levels in the minor allele homozygote group (GG) versus two other groups. Our results suggest that OPG polymorphism influences BMD in postmenopausal women, however further biological and/or functional evidence would be needed to confirm the suggestive influence of OPG polymorphisms on BMD.