Study Of The Relationship Between Carotid IMT And Plasma Endothelial Microparticle Level In Essential Hypertensive Patients

OBJECTIVETo investigate the changes of plasma endothelial microparticle (EMP) level and serum matrix metalloproteinase-2(MMP-2), matrix metalloproteinases-9(MMP-9),tissue inhibitor of metalloproteinase-1(TIMP-1) concentrations as well as carotid IMT and explore their relationships in essential hypertensive patients.METHODSAccording to Chinese Guideline Revised Edition for Prevention and Cure for Hypertension,72essential hypertensive patients were chosed.Then they were divided them into two groups based on carotid intima-media thickness(IMT) whether more than0.9mm,40patients with thicken (the thickening group) and32patients without thicken (the non-thickening group), and36normal persons served as healthy controls. The elected patients was record with age, height, weight, blood biochemical indicators and calculated body mass index (BMI).24hour ambulatory blood pressure was monitored and carotid artery ultrasound was used to measure carotid IMT. Blood samples were drawn in fasting state in the morning and then were set in the heparin sodium anticoagulation tubes and citric acid salt anticoagulation tubes, each tube3ml. Blood samples in citric acid salt anticoagulation tubes were centrifuged for270g for20min in order to get the rich Platelet plasma, followed by1500g centrifuge for20min to make the poor get Platelet-poor plasma (PPP). Flow cytometer was used to measure circulating CD31+/CD42-EMPs in PPP. Heparin sodium anticoagulation tubes were centrifuged for1000r/min for10min to get the blood serum,and enzyme-linked immunoassays was used to determine the concentrations of serum MMP-2,MMP-9and TIMP-1.RESULTS1) The comparison of general information among three groups For gender and age,the thicken group and the non-thickening group had no significant difference with the healthy control group (P>0.05),so for TG, TC, LDLC, HDLC, GLU,. BUN, Cr and URIC.While in BMI, SBP and DBP respects, the two hypertensive groups were significantly higher than those in the healthy control group (P<0.01),and the thicken group were also significantly higher than those in the non-thickening group (P <0.05)2) The result of ambulatory blood pressure The24hSBP、24hDBP、SBP and DBP in the day and night of the thicken group and the non-thicken group were significantly higher than those in the healthy control group (P<0.01), and the thicken group were also significantly higher than those in the non-thickening group (P<0.01)3) The result of plasma EMP level determination The plasma EMP level in the thickening and non-thickness group were significantly higher than those in healthy controls (P<0.01); the plasma EMP level in the thickening group were significantly higher than those in the non-thickening group.4) The result of concentrations of MMP-2,MMP-9and TIMP-1The concentrations of MMP-2,MMP-9and TIMP-1in the thicken group were significantly higher than those in the non-thicken group (P<0.01),while the MMP-2/TIMP-1and MMP-9/TIMP-1in the thickening group were significantly lower than those in the non-thickening group (P<0.05). In all the case groups,the values of MMP-2,MMP-9and TIMP-1were positive correlation with carotid IMT and plaque score (P<0.01), while the MMP-2/TIMP-1and MMP-9/TIMP-1were negative correlation with carotid IMT and plaque score (P<0.05).5) The correlations The plasma EMP level is positive correlated with carotid IMT (r=0.55,P<0.05) and plaque score (r=0.67,P<0.01). the values of MMP-2,MMP-9and TIMP-1were positive correlation with carotid IMT (r=0.86,0.76,0.87,P<0.01)and plaque score (r=0.75,0.69,0.87, P<0.01), while the MMP-2/TIMP-1and MMP-9/TIMP-1were negative correlation with carotid IMT (r=-0.78,-0.62,P<0.05) and plaque score (r=-0.76,-0.54,P<0.05)CONCLUSION1) The plasma EMP level could be used to evaluate the damage degree of carotid artery.2) MMP-2,MMP-9and TIMP-1are participate in the process of carotid atherosclerosis.