The Study About Polymorphism Of Vitamin D Receptor Gene FokI In Type 2 Diabetes Mellitus And Type 2 Diabete Mellitus With Atherosclerosis

Background and Objective Vitamin D is an essential vitamin in human, and its functions are mediated by vitamin D receptor (VDR). Recent studies have found that vitamin D has a protective effect on the islet, and is the necessary material of maintaining the normal glucose tolerance and insulin secretion. Therefore, the VDR gene may be one of the candidate genes of type 2 diabetes mellitus (T2DM). However, atherosclerosis (AS) which is macroangiopathy of T2DM is main cause of death and disability in T2DM. Many studies showed that the process of AS calcification was like that of the bone calcification. There are four restriction endonuclease cutting sites including BsmI,ApaI,TaqI,FokI which are related to human growth and disease. Some studies discovered that FokI genotypes were significantly difference between T2DM and normal controls. But there is few research which involves T2DM with AS. So the purpose of this research is to investigate the relationship between vitamin D receptor gene FokI polymorphisms and T2DM as well as T2DM with AS.Object and methods 175 T2DM patients (according to the criterion of diagnosis and classification of WHO 1999, newly diagnosed or identified diagnosed within one year )were divided to 69 AS patients and 106 non-AS patients by intima media thickness of great artery. 77 healthy physical examinees were enrolled as the controls group. Examing the clinical indicators of three groups. Blood DNA of three groups were extracted respectively. VDR gene polymorphism analysis was performed with polymerase chain reaction-restriction fragment length polymorphism in 175 T2DM patients and 77 controls. The genotype frequencies of VDR were calculated later according to Hardy-Weinberg equilibrium formula. Using single factor non -conditional Logistic regression analysis to study the incidence of VDR gene mutation in T2DM and T2DM with AS incidence.Results 1. Clinical parameter comparison of three group: WHR,BMI,DBP,FBG,TG,TC and LDL-c,HDL-c lever of T2DM group were higher than normal controls, the difference is significant(P>0.05). 2. A significant difference was seen in the frequency distribution of VDR FokI genotype between T2DM and normal controls. 3. VDR FokI restriction Enzyme cutting site genotypes were no significant difference between T2DM and T2DM with AS. 4. Allele f was positively correlated to T2DM; allele F was negative correlated to T2DM.Conclusions 1. VDR FokI restriction Enzyme cutting site genotypes were significant difference between T2DM and normal controls. 2. There were no difference in VDR FokI restriction Enzyme cutting sites genotypes between T2DM and T2DM with AS. 3. Allele f maybe a susceptible gene contributing to the development of T2DM, whereas allele F maybe protective gene for T2DM.