Variantions In The Promoter Of Osteoprotegerin Gene And Its Association With Diabetic Osteoporosis

Objective:Variantions in the promoter of osteoprotegerin (OPG) gene were reported to contribute to the bone mass density(BMD) in patients with postmenopausal osteoporosis, however, its relationship with diabetic osteoporosis(DO)still unclear. In this study four single nucleotide polymorphisms (SNPs):A163G,G209A,T245G, and T950C in OPG promoter region were genotyped in263type2diabetic patients.Methods:A163G,G209A and T245G polymorphisms were genotyped with TaqMan allelic discrimination assay and T950C polymorphisms with polymerase chain reaction-restriction fragment length method in178Non-DO(NDO) and85DO patients. BMD at lumbar spine, hip and forearm was assessed by dual-energy X-ray absorptiometry.Results:(1) The frequencies of genotypes in263type2diabetic patients were as follows:AA (71.1%).AG (25.5%), GG (3.4%) for A163G polymorphism; GG (74.9%), GA(24.3%), AA (0.8%) for G209A polymorphism; TT(73.0%).AG (25.5%), GG (1.5%) for T245G polymorphism. And TT(58.2%), TC (34.2%), GG (7.6%) for T950C polymorphism. The genotype distribution of each polymorphism site was met with Hardy-Weinberg equilibrium (P>0.05).(2) There were no significant differences in the genotype and allele distributions of A163G,G209A,T245G and T950C polymorphism between DO group and NDO group at the two sites (P>0.05).(2) In DO group:AA carriers of A163G polymorphism had higher L1and L1-L4BMD than that of AG+GG carriers.. But no significant difference in BMD at the trochanter; femoral neck. Wards triangle. andL2,L3.L4; and no significant difference in BMD was seen in different G209A,T245G and T950C genotypes in DO group(P>0.05).Conclusions:A163G. G209A,T245G and T950C genotype distributions of OPG gene had evident race and regional diversity. A163G polymorphism in the promoter region of the OPG gene may contribute to the genetic regulation of BMD in DO patients, in which allele A may be the protection factor of bone mass and allele G may be the risk factor of bone mass. G209A,T245G and T950C polymorphism in the promoter region of OPG gene may not be associated with BMD.