Association Of VDR Gene Polymorphism With Osteoporotic Vertebral Fracture Types And QCT Of Lumbar Spine

Objective:To investigate the association of VDR gene polymorphism with the type of osteoporotic vertebral fracture and lumbar spine QCT.Methods:1.A total of 60 patients with osteoporotic thoracolumbar fractures were selected from the First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine,and peripheral blood samples were collected.VDR gene polymorphism and its classification were detected by PCR-RFLP technique;2.Osteoporotic vertebral fractures were classified by Genant semi-quantitative method;3.Bone mineral density(BMD)of L2-L4 vertebral cancellous bone was measured in 60 patients,and they were divided into mild osteoporosis group(QCT value 80-120 g/L),moderate osteoporosis group(QCT value 40-80 g/L),and severe osteoporosis group(QCT value<40 g/L)according to lumbar QCT values;4.The association between VDR gene polymorphism and osteoporotic vertebral fracture type and the association between VDR gene polymorphism and lumbar QCT were detected by statistical methods.Results:1.Of the 60 patients,0 were detected with VDR genotype BB,28with genotype Bb and 32 with genotype bb.The distribution of the number of cases of each fracture type in 110 injured vertebrae in 60 cases was significantly different between the Bb group and the bb group(all P<0.05).The total number of patients with type 0 and type I vertebral fractures in group Bb accounted for 5 patients with a total of 7 vertebral bodies(7/53accounted for 13.21%),compared with 18 patients with a total of 39 vertebral bodies(39/57 accounted for 68.42%)in group bb,the difference had statistical significance(x~2=62.766,P<0.01).However,the total number of type I and type II vertebral fracture types in the Bb group accounted for 29patients and a total of 40 vertebral bodies(40/53 accounted for 70.47%),and there was no significant difference compared with 20 patients and a total of38 vertebral bodies(38/57 accounted for 66.67%)in the bb group(x~2=1.554,P=0.213>0.05)2.In the mild osteoporosis group,there were 3 patients(3/28accounted for 10.72%)in the Bb group,and there was no statistically significant difference compared with 10 patients(10/32 accounted for 31.25%)in the bb group(x~2=3.711,P=0.054>0.05).In the moderate osteoporosis group,there were 15 patients in the Bb group(15/28 accounted for 53.57%),compared with 18 patients in the bb group(18/32 accounted for 56.25%),and the difference was nostatistically significant(x~2=0.043,P=0.835>0.05).However,10 patients(15/28 accounted for 35.71%)in the Bb group with severe osteoporosis were compared with 4patients(4/32 accounted for 12.50%)in the bb group,and the difference was statistically significant(x~2=4.499,P=0.034<0.05).Conclusion:1.The different genotypes of VDR in patients with osteoporotic vertebral fracture are associated with different types of fractures.Patients with Bb genotype are more likely to have type II and type III vertebral fractures than those with bb genotype.2.Different genotypes of VDR were associated with lumbar spine QCT in patients with osteoporotic vertebral fracture,and patients with Bb genotype were more likely to have lower bone mineral density than those with bb genotype.