Effects Of Cardiotrophin-1 In Type 2 Diabetic Cardiovascular Disease

Backgroud and Objective Type 2 diabetes is associated with a marked increased(by a factor of two to four) in the risk of coronary heart disease. A lot of research revealed that diabetes is associated cardiovascular disease, and is an independent risk factor of coronary heart disease. Cardiovascular disease may begins before the onset of type 2 diabetes. In the earlier period of diabetes, there are some alterations of ultrastructure in myocardium cells and cardiac function. In the last stage, there exist of some degree of damage with systolic and diastolic functions of the heart, its weight obviously increased, and thickening of myocardium continuing existed. Cardiotrophin-1 (CT-1) is a newly isolated cytokine that was identified based on its ability to induce cardiac myocyte hypertrophy in vitro. It is a member of the interleukin-6 cytokine superfamily and have broad spectrum biological activity. CT-1 has myocyte hypertrophic and cardioprotective properties, and play a important role in growth of heart, cardiac hypertrophy and cardiac disease. CT-1 overly expressed in some pathologic status such as myocardial infarction, experiment cardiomyopathy, congestive heart failure and genetic hypertension. Does CT-1 takes part in the development of diabetic cardiovascular disease or not? We established the Biotin-Streptavidin-enzyme-linked immunosorbent assay (BSA-ELISA) of human CT-1 in plasma to measure the levels of plasma CT-1 in type 2 diabetes complicated with coronary heart disease and hypertension. To study the effect and significance of changes of plasma cardiotrophin-1 (CT-1) in type 2 diabetic cardiovascular disease.Methods The assay of human plasma CT-1 was established with BSA-ELISA. Used the method to observed the CT-1 levels of plasma type 2 diabetes, diabetes complicated with cardiovascular disease (coronary heart disease, hypertension) and normal controls, carrying out the correlation and regression analysis with patients age, body mass index (BMI), blood pressure, creatinine, blood lipid, fast plasma glucose, Hemoglobin Alc and myocardium enzyme. To study the significance of changes of plasma cardiotrophin-1 (CT-1) in type 2 diabetic cardiovascular disease.Results ?We used the Biotin-Streptavidin-enzyme-linked immunosorbent assay(BSA-ELISA) to established the assay of human CT-1 in plasma: the assay is based on a double-antibody sandwich technique. The well of the plate supplied with the kit are coated with anti-human CT-1 specific mouse IgGi. After adding CT-1 standards and plasma samples to be measured, biotinylated anti-hunman CT-1 specific goat IgG was used as second antibody. And then, added StreptAvidin-HRP-IgG detection solution and colour was revealed with OPD. According to standard curves, concentration of CT-1 in sample was determined. The working rang of standard curve was 10~2000pg/ml, and the minimum detectable limit of the assay was lOpg/ml. Variance coefficient within group was 1.76%~7.64%; variance coefficient between groups was 5.96%~9.04%.?The levels of plasma CT-1 in T2DM+CHD group (465.38±102.23pg/ml) was apparently higher than that of CHD group (382.59±94.68 pg/ml, PO.05), T2DM group (99.56±21.77pg/ml, P<0.01)and NC (31.46±9.73pg/ml, PO.001), the level in CHD group was significantly higher than that of the T2DM group (PO.01) and NC (PO.01), and the level in T2DM was higher than that of NC (PO.05). The level of plasma CT-1 was related with blood pressure and myocardium enzyme: Creatine kinase (R=0.795, PO.001); Hydroxybutyric acid dehydrognase (R=0.647, PO.001); Diastolic blood pressure (R=0.484, PO.001); Systolic blood pressure (R=0.422, PO.001); Lactic acid dehydrognase-1 (R=0.381, PO.01); Isoenzyme of creatine kinase (R=0.345, PO.05). Stepwise regression analysis revealed that Creatine kinase (CK) was the most significant agent affecting the plasma CT-1.(3) The level of plasma CT-1 in diabetes complicated with hypertension group (269.29±65.30 pg/ml) was apparently higher than that of type 2 diabetes group (99.54±27.17 pg/ml , PO.001) and normal controls (31.46±9.73 pg/ml , PO.001); and the level in type 2 diabetes group was significantly higher than that of normal controls (PO.05). The level of plasma CT-1 was correlated with Systolic blood pressure (R=0.660, PO.001), Diastolic blood pressure (R=0.428, PO.001), Triglyceride (R=0.403, PO.001), ApolipoproteinB (R=0.335, PO.001),ApolipoproteinA (R=0.189, P<0.001), Total cholesterol (R=0.183, P<0.05) and Low density lipoprotein (R=0.171, P<0.05). Stepwise regression analysis revealed that Systolic blood pressure, Diastolic blood pressure and ApoIipoproteinB were the most significant agents affecting the plasma CT-1.Conclusions This BSA-ELISA of plasma CT-1 was specific, sensitive andconvenient, suitable for clinical and foundation researches. The elevation of plasma CT-1 in type 2 diabetes patients suggests that cardiovascular disease initiated early in the presence of diabetes; Plasma CT-1 elevated furthered more in diabetes complicated with coronary heart disease, it indicated the severe degree of diabetic cardiovascular disease. CT-1 can be act as a marker of diabetic cardiovascular disease. The plasma CT-1 was related with hypertension in type 2 diabetes suggested that hypertension aggravated diabetic cardiovascular disease.