Association Between The Bg1Ⅱ Polymorphism Of The α₂β₁ Integrin Gene And Diabetic Angiopathies

Objective: To investigate the distribution of Bg1Ⅱgene polymorphisms ofα2β1 integrin and its association with diabetetic angiopathies in Chinese Han nationality patients.Methods: The patients were genetically unrelated Chinese subjects who had been diagnosed with type 2 diabetes mellitus, monitored on a regular basis at the outpatient clinic or during hospitalization at Zhongda Hospital (Nanjing, Jiangsu). They were divided into 2 groups. The first group included 258 patients diabetetic angiopathies comprised 76 patients with coronary heart disease (CHD), 74 diabetic nephropathy and 74 diabetic retinopathy patients.The second group consisted of 116 diabetes patients without angiopathies. The control group comprised 107 normally healthy subjects. A subject's clinical data was collected, their genomic DNA was then isolated from their peripheral blood leukocytes. Genotypes and frequencies of Bg1Ⅱwere examined by the PCR-restriction fragment length polymorphism technique. All data was analyzed by SPSS 12.0 for windows.Results: The ratio for Bg1Ⅱ+/+ type gene in CHD patients with type 2 diabetetes was significantly higher than in patients with diabetes and without angiopathies and than in the health control group (56%vs23.3%,39.3%).(P<0.001). The different Bg1Ⅱgene type would suggest an increased risk of serious CHD as diagnosed using coronary angiography. However there wasn't a strong correlation (the correlation coefficient was lower than 0.5). The frequency of Bg1Ⅱallele showed significant differences in the insulin resistence index. The distribution of Bg1Ⅱgenotype and frequency of Bg1Ⅱallele was significantly higher in diabetic nephropathy than in diabetic retinopathy and in the control group (P<0.05). And it was significantly higher in diabetic retinopathy than in the control group(P<0.05). The frequency of Bg1Ⅱ++ allele was significantly higher in diabetic angiopathies than that in the controls (P<0.05). Bg1Ⅱ++ genotype may be a risk factor for diabetic angiopathies (OR=1.909,95% CI:1.131~3.224, P=0.015). There is no difference in the serum HDL level between diabetic angiopathies and the control group (p>0.05). The distribution of Bg1Ⅱgenotype and frequency of Bg1Ⅱallele did not differ between the diabetes patients without angiopathies group and normally healthy subjects. There was also no association of the different genotype with the plasmic lipid level.Conclusion: Chinese Han nationality patients with diabetic angiopathies had higher frequencies of Bg1Ⅱ++ genotype and Bg1Ⅱ++ allele polymorphism ofα2β1 integrin gene. Bg1Ⅱ++ genotype was not associated with plasmic lipid level in diabetic angiopathies patients nor in the two control groups. Therefore the Bg1Ⅱ++ allele polymorphism of theα2β1 integrin gene is possibly a high risk factor for diabetic angiopathies and Bg1Ⅱgenotype might be significant during the develepment of insulin resistence and diabetic nephropathy.