Study On Relationship Between Bone Mineral Density And Polymorphisms Of Vitamin D Receptor Gene Of Female Adults In Hans In Jinan Area

Objective: To understand the normal values and changes of bone minernal density (BMD) and investigate the relationship between BMD and vitamin D receptor(VDR)- Fok1 and VDR-Bsm I gene polymorphism of healthy female adults of the Han nationality in Jinan area. All will provide the criteria for diagnosis and treatment of osteoporosis in Jinan, and could give the trace for further study of osteoporosis.Methods: Firstly, BMD of lumbar spine and proximal femur (femoral neck, ward and troch anteric areas) were measured by dual energy X-ray absorption. Secondly, the genotypes of vitamin D receptor were analyzed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) . DNA was isolated from whole blood using fast methods. VDR primers were used to the polymerase chain reaction (PCR) respectively. Then,the PCR products of VDR were digested with restriction endonuclease respectively. Instantly, the products of endonuclease were visualized and recorded under UVIpro analyzed instrument. The association between the genotypes of VDR and VDR and BMD was analyzed separately. The experimented data was demonstrated in x±s deviation. The analysis of variance and analysis of covariance were used to the significance test by sas 6.12 software. P<0.05 was considered to be significant difference .Results: 1. Peak bone mass (PBM)of lumbar spine and femoral neck, wards traingle and troch anteric areas of female adults this area was (1 .214±0.135)g/cm~2, (0.999±0.102)g/cm~2,0.926±0.149 and 0.831±0.121g/cm~2 , respectively, while the PBM -age- group was 35-39, 25-29, 20-24 years old group respectively. There was a tendency that decreased BMD with the increasing age after BMD peak-year, both lumbar spine and femur BMD loss speed up after menopausal in female. Statistics showed hat BMD of femur in the age groups of 50-54 and 70-74 was significant different compared with the former age group ( P<0.05 );while BMD of lumbar vertebrae was similar in the 50-54 age group,it was slightly increased in the group 65-74 years old,though it wasn't significant different (P >0 05).2. The frequencies for Fok I-vitamin D receptor gene polymorphism: There were Ff type 71.5% (143/200), ff type 20.5% (41/200), FF type 8% (16/200) and were bb type 78.1%, Bb type 43%, BB type 0.5% respectively in female adults, And the alleles of f and b are more than that of F and B in Jinan area,about 56.25% and 88.7% respectively. Harding-Weinberg equilibrium was evident for VDR-Fok I and VDR-Bsm I gene polymorphisms.3. FF genetype of VDR-Fok I had higher BMD values at lumbar vertebrae and femoral neck compared with Ff and ff genetypes in the women group under 40years old(p<0.05) ,while bb genetype of VDR-Bsm I had higher BMD values at the Wards triangle compared with Bb genetype (p<0.05) . There was no relationship between VDR genetypes and BMD in other groups (p>0.05) .Conclusion: 1. The normal ranges and characteristics of BMD in the lumbar vertebrae and femur of healthy female adults in Jinan area are gained in this study. The PBM and the PBM -age- group in four measured section were different, lumbar spine's PBM was the highest but appeared latest, while Peak bone mass (PBM)of wards traingle and troch anteric areas were the lowest and appeared earliest. BMD of every femoral section changed similarly and lost quickly after menopausal and 70 years old, while the BMD of the lumbar vertebrae'loss was not apparent; The bone loss of the lumbar spine which PBM appeared late and high was less than any section of femur.2. The frequencies of Ff genetype was higher than ff and Ff genetypes in the female adults this area ,while that of bb is higher than Bb genetype.f and b was the commonest allele ,Vitamin D receptor gene is one with certain populational diversity compared with other groups.3. FF genetype of VDR-Fok I had higher BMD values at lumbar vertebrae and femoral neck compared with Ff and ff genetypes in the women group under 40 years old ,while bb genetype of VDR-Bsm I had higher BMD values at the Wards triangle compared with Bb genetype.A high BMD of lumbar vertebrae and femoral neck was associated with the F allele in the women younger than 40years old ,while the high BMD of the Wards triangle was associated with the b allele in the same age group. There was no relationship between VDR genetypes and BMD in other groups. The results suggested that there was association between VDR genotypes and BMD in women and the VDR-Fok I, VDR-Bsm I genotypes can be used as a special genetic markers in predicting the risk of osteoporosis in the Han nationality in Jinan Area.