Objective: To investigate the impact of multiple candidate genes on bone mineral density in postmenopausal women.
Methods: Bone mineral density (BMD) at lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry (DEXA) in 205 postmenopausal women. Polymerase chain reaction (PCR) and direct sequencing technique were used to identify osteoprotegerin gene polymorphism. Parathyroid hormone, calcitonin receptor, osteocalcin and leptin receptor genes were evaluated through PCR and restriction fragment length polymorphism. Leptin gene was genotyped by PCR and agarose electrophoresis.
Results: One G-1181C single nucleotide polymorphism was found in the first exon of the osteoprotegerin gene. After adjustment for age and body mass index, women who were with the CC genotype of osteoprotegerin gene or the bb genotype of parathyroid hormone gene had the highest BMD value at the lumbar spine, which was (1.042 +/- 0.142) g/cm(2) and (1.196 +/- 0.133) g/cm(2), respectively. No association was found among calcitonin receptor, osteocalcin, leptin and leptin receptor genes with BMD in postmenopausal women. Multivariate regression analysis found that the osteoprotegerin, parathyroid hormone and osteocalcin genes associated with the variance of BMD at the lumbar spine, and the parathyroid gene associated with the variance of BMD at the femoral neck.
Conclusions: There is some association between osteoprotegerin, parathyroid hormone genes and BMD in postmenopausal women. However, no relationship has been found among calcitonin receptor, osteocalcin, leptin and leptin receptor genes with BMD in postmenopausal women. The osteoprotegerin gene may be the useful genetic marker for osteopenia in postmenopausal women.