Serum A-FABP Levels And Its Expression In Atherosclerotic Plaques Of Diabetes Mellitus

ObjectiveBy testing adipocyte fatty-acid binding protein in serum and atherosclerotic plaques of type 2 diabetes patients with/without atherosclerosis, to investigate the association of A- FABP with type 2 diabetes mellitus and atherosclerosis.MethodsExperiment I69 patients with type 2 diabetes mellitus(T2DM)were enrolled in the study . 37 male, 32 female , 31～77 age, disease duration 2 months～21years . According to atheroscleros- is, they were divided into diabetic non-atherosclerotic group(A group),which is 32 cases, 17 males and 15 females, mean age 52.0±9.6 years,mean disease duration 9.1±2.4 years and di- abetic atherosclerotic group(B group),which is 37 cases, 20 males and 17 females, mean a- ge 50.4±11.3 years, mean disease duration 10.2±2.1 years. diabetic atherosclerotic group an- d diabetic non-atherosclerotic group were matched in age and sex.at the same time, 43 patie- nts(C group) with atherosclerosis non-diabetes were enrolled in the study,22males and 21 f- emales, mean age 52.8±10.5 years,mean disease duration 9.4±3.1years. The control group is health check personnel(D group),31 cases, 16 males and 15 females, mean age 48.0±5.9 y- ears. Serum levels of A-FABP were measured by enzyme-linked immunosorbent assay.Experiment IIAtherosclerotic samples were obtained from 81 patients undergoing carotid endartere- ctomy (CEA) and amputation,among those samples,51 are from T2DM patients (E group), which patients are 28 males and 23females, mean age 57.2±12.2 years,mean disease dura- tion 16.9±4.6 years and 30 are from non-diabetic patients (F group), which patients are 16 males and 14 females, mean age 58.9±12.9 years,mean disease duration 18.1±5.7 years. The samples were distinguished into four pathological stages by two pathologists in a blinded m- ethod. Group E includes stageⅠ9 cases, stageⅡ10 cases, stageⅢ12 cases, stageⅣ20 cases, group F includes stageⅣ30 case . In addition,10 normal arteries as control group (G group) were obtained from patients undergoing amputation,which patients 5 males and 5 females, mean age 56.8±11.7 years,were not with diabetes, hypertension, coronary heart disease and cerebrovascular disease.Expression of A-FABP in atherosclerotic arteries were measured by two-step immunohistochemical method.400 high power and 5 fields were selectedrandom- ly,then the percentage of positive cells was calculated and named as A-FABP label index. All of the statistical data was processed with SPSS 13.0 software.ResultsExperiment IDiabetic have-atherosclerotic group, diabetic non-atherosclerotic group and atheroscl- erotic group compared with the control group, the serum levels of A-FABP were higher (P < 0.01). Diabetic have-atherosclerotic group were higher than diabetic non-atherosclerotic gr- oup and atherosclerotic group , atherosclerotic group compared with the diabetic group, the serum levels of A-FABP were higher (P < 0.01)Experiment IIIn the control arteries regularly arranged elastic fibers and SMC.In these atherosclerotic arteries,macrophage and SMC are seen accumulated largely under the endothelial.Immunohistochemical staining showed anti A-FABP is brown immune complex particles accumulated in the foam cell of normal arteries and atherosclerotic arteries. But it is striking differences between diabetic have-atherosclerotic group and control group. The number of control group is little,while diabetic have-atherosclerotic group is much(P <0.01).In different stages of diabetic have-atherosclerotic group the expression of A-FABP were significantly different (P<0.01). In the last stage of atheroselerosis,diabetic have-atherosclerotic group compared with the atherosclerotic group, expression of A-FABP in atherosclerotic lesions is no significant differences, not statistically differences. (P> 0.05)Conclusion1. Serum A-FABP are risk factors of diabetes.2. Serum A-FABP are risk factors of atherosclerosis.3.A-FABP take part in the development of diabetes and vascular complications .A-FABP levels in atherosclerotic lesions are associated with an serious plaque phenotype.4. There is not a necessary link between serum glucose levels and A-FABP levels in atherosclerotic lesions in the last stage.