Vitamin D receptor gene polymorphism and bone mineral density in patients with type 2 diabetes mellitus

Objective To explore the relationship between vitamin D receptor (VDR) gene polymorphisms and bone mineral density (BMD) in patients with type 2 diabetes mellitus (DM) an d to better understand the pathogenesis of osteoporosis. Methods Ninety seven patients with type 2 DM were recruited for this study. BMD was mea sured by single photon absorptiometry at the lower one third of the nondominant radius and ulna. Polymorphisms of the VDR gene were analyzed by DNA amplificati on with polymerase chain reaction (PCR) and endonuclease digestion with Bsm Ⅰ. Results The respective frequencies of VDR genotypes were BB 18. 6%, Bb 27. 8% and bb 53 . 6%. The Z scores of the three groups were -1. 57±-0. 60, -1. 45±-0. 67 and -1. 41±-0. 81, respectively. Although the BMD of the Bb genotype DM patients was higher than that of BB genotype DM patients and lower than that of bb genoty pe DM patients, there were no significant differences. Conclusion These findings suggest a small influence of VDR gene polymorphism on the BMD of patients with type 2 DM. Further study on the value of VDR genotypes in the pat hogenesis of osteoporosis in diabetes mellitus is still needed.