Changes Of Inflammatory Cytokines, Carotid Intima-Media Thickness And Vascular Endothelial Function In Hypercholesterolemia And Effects Of Statins On Its

1 ObjectiveIncidence of atherosclerosis and Coronary Heart Disease(CHD) steps up year by year,and threatens healthy and life of human.It is known to all that hypercholesterolemia is important risk factor of atherosclerosis and coronary heart disease.Atherosclerosis and Coronary Heart Disease(CHD) are known as chronic inflammatory process in arterial wall,and systemic inflammatory markers have considerable significance in estimating atherosclerotic prognosis.Recent years the study confirms that decreased serum concentration of antiinflammatory cytokine (interleukin-10),which has a protective role in atherosclerosis,is associated with clinical instability in acute coronary syndrome.Increased proinflammatory cytokines (interleukin-6 and tumor necrosis factor-a) are shown to play a role in the development of acute coronary syndromes.A few studies confirm that carotid intima-media thickness(IMT) and endothelium-dependant flowing-mediated dilation(EDFMD) can evaluate atherosclerosi.Statins is one of lipid-modulating drugs in effect now.A large number of basic and clinical trials showed that statins had various non-lipid-modulating effects especially anti-inflammatory effect,stabilizing plaque and improving endothelial function besides significantly improving serum lipids.It is seldom to do research about the changes of inflammatory cytokines, carotid intima-media thickness and vascular endothelial function in hypercholesterolemia and effects of statins on its in patients with hypercholesterolemia.This study explores the changes of inflammatory cytokines, IMT and EDFMD,the correlation between inflammatory cytokines and IMT and effects of statins on its in patients with hypercholesterolemia,in order to offering theory and clinical practice foundation of preventioning and curing atherosclerosis and Coronary Heart Disease.2 Subjects and Methods2.1 SubjectsWe collected hypercholesterolemic patients according to diagnostic criteria of hypercholesterolemia in"Chinese blood-fat abnormality preventioning and curing guide",including TC≥5.18mmol/L,DL-C≥3.37mmol/L.The study population consisted of 110 consecutive outpatients between the ages of 18 and 70 years,average 56.5±10.7 years of age with hypercholesterolemia,including 47 men and 63 women. Hypercholesterolemic patients stopped to take other lipid-modulating drugs in period of study.The exclusion criteria were as follows:Ⅰacute coronary syndrome,Ⅱcongestive heart failure,Ⅲhypothyroidism,nephrotic syndrome,alcoholism,lupus erythematosus and other inflammatory desease,Ⅳuncontrolled diabetes mellitus or hypertension,Ⅴhistory of severe liver disease.The control group comprised 30 healthy volunteers,including 13 men and 17 women,average 57.4±10.8 years of age.Concomitant medications remained unchanged.Patients and healthy volunteers gave their written informed consent.2.2 Methods2.2.1 GroupThe reseach was random,control,single-blind design.Hypercholesterolemic patients(n=110) were randomly divided into three groups:the rosuvastatin group(n=36),the atorvastatin group(n=38) and the diet therapy group(n=36) according to random digits table,the control group comprised 30 healthy volunteers.2.2.2 MeasurementsAll the participants underwent examination,including recording age and gender, measuring body height and body weight.Study subjects were asked to refrain from eating or drinking anything other than water for 12 hours before every blood sampling. Blood samples were taken 6ml venous blood.All blood samples were drawn from an antecubital vein and collected in two tubes.One tube contained 3ml venous blood using for detecting blood-fat by enzymic method.Blood sample in another tube was centrifuged within 2 hours at 2,000rpm for 20 minutes.Serum was then aliquoted into EP tubes and stored at -70℃until assay.Serum in EP tubes was detected for IL-6, IL-10 and TNF-αby radioimmunoassay(R/A).Blood-fat and Serum levels of IL-6,IL-10 and TNF-αwere detected by same methods after 8 weeks.Carotid intima-media thickness was assessed by SEQUOIA 512 color Doppler ultrasound made in USA and endothelium-dependant flowing-mediated dilation of brachial artery was assessed by HP-5500 color Doppler ultrasound blood vessel display made in USA.2.2.3 Therapeutic methodsHypercholesterolemic patients(n=110) were randomly divided into three groups: those in the rosuvastatin group(n=36) who were assigned to treatment with 10mg/d rosuvastatin and diet therapy for 8 weeks,likewise those in the atorvastatin group(n=38) who were assigned to treatment with 10mg/d atorvastatin and diet therapy for 8 weeks,however those in the diet therapy group(n=36) who were administered diet therapy for 8 weeks merely.The National Cholesterol Education Program(NCEP) Expert Panel on detection,evaluation,and treatment of high blood cholesterol in adults(Adult Treatment PanelⅢ) recommends therapeutic lifestyle changes(TLCs),including a TLC diet as a first line of therapy for clinical management of high blood cholesterol levels.The TLC diet was designed to provide 16%of calories as protein,56%as carbohydrate,and 28%as fat(7%saturated,8% monounsaturated,and 13%polyunsaturated) and 66 mg cholesterol per 1,000 kcal. Concomitant medications remained unchanged.The subjects were encouraged to maintain their habitual level of physical activity throughout the study period.Healthy volunteers were not treated.3.Results3.1 Comparison of inflammatory cytokines and comparison of blood-fat among four groups before treatmentBefore treatment,the serum levels of TC,,TG,LDL-C,IL-6 and TNF-αin the patients of the rosuvastatin group,those of the atorvastatin group and those of the diet therapy group were significantly higher than that of healthy subjects(P≤0.001), however the serum levels of IL-10 was significantly lower than that of healthy subjects(P=0.000).The serum levels of TC,TG,LDL-C,HDL-C,IL-6,IL-10 and TNF-αwere not significantly difference among patients of the rosuvastatin group,those of the atorvastatin group and those of the diet therapy group(P＞0.050).The IMT and the EDFMD also were not significantly difference among patients of the rosuvastatin group,those of the atorvastatin group and those of the diet therapy group(P＞0.050).3.2 Comparison of the IMT and comparison of the EDFMD among four groups before treatmentBefore treatment,in the patients of the rosuvastatin group,those of the atorvastatin group and those of the diet therapy group,the IMT was significantly higher than that of healthy subjects(P=0.000),however the EDFMD was significantly lower than that of healthy subjects(P=0.000).3.3 Correlation between inflammatory cytokines and IMT in hypercholesterolemiaIn patients with hypercholesterolemia,IL-6 showed a positive correlation with IMT(r=0.636,P=0.000);TNF-αalso showed a positive correlation with IMT (r=0.241,P=0.011);IL-10 showed a negative correlation with IMT(r=-0.501, P=0.000).3.4 Comparison of inflammatory cytokines and comparison of blood-fat before treatment and after treatment in the rosuvastatin group,the atorvastatin group and the diet therapy groupAfter 8 weeks of rosuvastatin treatment and atorvastatin treatment,the serum concentration of TC,TG,LDL-C,IL-6 and TNF-αwere decreased significantly (P≤0.003),but the serum levels of IL-10 was increased significantly(P=0.000) and that of HDL-C did not change obviously(P≥0.146).After 8 weeks of diet treatment,the serum concentration of TC,TG,LDL-C,were decreased significantly(P≤0.030),but the serum levels of IL-6,IL-10 and TNF-αdid not change obviously(P≥0.063).Compared the diet therapy group after 8 weeks of diet treatment,the serum concentration of TC,LDL-C,IL-6 and TNF-αwere decreased significantly in the patients of the rosuvastatin group and those of the atorvastatin group after 8 weeks treatment(P≤0.004),but the serum levels of IL-10 was increased significantly(P=0.010).3.5 Comparison of the IMT and comparison of the EDFMD before treatment and after treatment in the rosuvastatin group,the atorvastatin group and the diet therapy groupThe IMT was decreased significantly(P=0.000) and the EDFMD was increased significantly(P=0.000) after 8 weeks of rosuvastatin treatment and atorvastatin treatment.The IMT and the EDFMD also did not change obviously(P≥0.213) after 8 weeks of diet treatment.The IMT was decreased significantly(P=0.002) and the EDFMD was increased significantly(P=0.000 ) in the patients of the atorvastatin group and those of the atorvastatin group compared the diet therapy group after 8 weeks. 4.ConclusionsThis study indicates that Hypercholesterolemic patients exist unbalance of antiinflammatory cytokine and proinflammatory cytokine,antiinflammatory cytokine being significantly lower than that of healthy subjects and being significantly higher than that of healthy subjects.This study also discovers in patients with hypercholesterolemia IL-6 showed a positive correlation with IMT,TNF-αalso showed a positive correlation with IMTand IL-10 showed a negative correlation with IMT.In patients with hypercholesterolemia,the IMT was significantly higher than that of healthy subjects,however the EDFMD was significantly lower than that of healthy subjects.Rosuvastatin and atorvastatin can increase the serum level of IL-10 significantly and decrease the serum levels of IL-6 and TNF-αin hypercholesterolemia.After rosuvastatin treatment and atorvastatin treatment,the IMT was decreased significantly and the EDFMD was increased significantly.Results of this study indicate antiinflammatory cytokine lowering and proinflammatory cytokine heightening are important mechanism of occurrence and development of artherosclerosis.Changes of the IMT and the EDFMD prove that hypercholesterolemia exists artherosclerosis and damage of vascular endothelial function.Rosuvastatin and atorvastatin can improve unbalance of antiinflammatory cytokine and proinflammatory cytokine,stabilize plaque and improve endothelial function,which may be one of mechanisms of its curing artherosclerosis and its improving cardiovascular disease prognosis.