ABSTRACT
OBJECTIVE: To determine whether polymorphisms of the Vitamin D receptor (VDR)gene,known to be associated with osteoporosis and/or osteoarthritis (OA) in Caucasians,might also relate to the risk of OA and osteoporosis in Korean postmenopausal women METHODS: A population of 130 postmenopausal women,including 76 healthy controls and 54 knee OA patients,were studied using anteroposterior radiographs of the knee,which were graded for OA according to the Kellgren classification system.The VDR genotype was determined by using polymerase chain reaction and by digestion with the three restriction enzymes Taq I,Bsm I,and Apa I.Femoral neck bone mineral density (BMD)was assessed in all participants by dual energy X-ray absorptiometry . RESULTS: VDR genotype frequency distributions in Koreans were much different from Caucasian's both in the OA group and the control group.Especially, "t t", "B B" and "A A" genotype were very rare,prominently differentiating from Caucasians.But within Koreans,no significant differences in VDR genotype frequencies were observed between OA cases and controls.VDR genotype was not significantly associated with the radiographic grades of OA.And there were no significant relationships of VDR genotype with BMD scores in each group. CONCLUSION: In Korean postmenoposal women,the VDR gene polymorphisms do not significantly contribute to an increased prevalence of knee OA or to differences in BMD.VDR genotype analysis would not be helpful for assessing the risk of knee OA in Koreans because :(1)there is no correlation of VDR genotypes with the radiographic severity of OA ;and (2)there is a more skewed distribution of VDR genotypes in Korean population compared to the Caucasian's .