Lipoprotein-associated Phospholipase A2: Its Association With Coronary Artery Disease And Relationship With Lipids And Inflammation Biomarkers

【Objective】Atherosclerosis is a common pathophysiologic basis of the cardiovascular disease.In the past,it was thought caused by the disorder of lipid metabolism. Therefore,some harmful lipids were regarded as the traditional risk factors of coronary artery disease(CAD).However more and more studies suggest that atherosclerosis is a chronic inflammatory disease instead.Lipoprotein-associated phospholipase A2(Lp-PLA2)was a newly found inflammatory biomarker.It can hydrolyze oxidized phospholipids to lysophosphatidylcholine and oxidized free fatty acids,by which to cause atherosclerosis.Consequently,Lp-PLA2 may be a new potential risk factor for CAD.Our aim is to determine the association between the serum Lp-PLA2 activity and the risk of CAD,and to investigate the relationship of serum Lp-PLA2 activity to blood lipids,inflammatory markers and some other traditional risk factors of CAD. 【Methods】Serum Lp-PLA2 activity and the levels of triglyceride(TG),total cholesterol(Tch),low density lipoprotein-cholesterol(LDLc),high density lipoprotein-cholesterol(HDLc),apolipoproteinAⅠ(apoAⅠ),apolipoproteinB (apoB),high-sensitivity C-reactive protein(hsCRP),white blood cell(WBC), glucose(Glu)and uric acid(UA)were measured in 162 CAD patients confirmed by angiography and 53 healthy controls.The correlation of Lp-PLA2 with the above indicators was analyzed and serum Lp-PLA2 activity between CAD patients and healthy controls was compared.There were 36 stable CAD patients and 126 ACS patients in the 162 CAD patients.The 126 ACS patients consisted of 91 UAP patients and 35 AMI patients.These patients were divided into four groups according the degree of narrowness and the numbers of lesioned main coronary arteries.Among those,37 patients had coronary artery atherosclerosis, 56 patients had one coronary artery lesion,37 patients had two coronary arteries lesion and 32 patients had three coronary arteries lesion.And the relationship between serum Lp-PLA2 activity and the severity/stability of coronary atherosclerosis was compared.Furthermore,some other traditional risk factors of CAD were investigated and the relationship between the factors and serum Lp-PLA2 activity was analyzed. 【Results】1.Lp-PLA2 activity was significantly higher in CAD patients than those of controls(476±148U/L VS 402±116 U/L,P=0.001).2.Lp-PLA2 activity in the groups of coronary artery atherosclerosis was 486±163 U/L,the group of one coronary artery lesion was 472±118 U/L,the group of two coronary arteries lesion was 465±178 U/L,the group of three coronary arteries lesion was 482±144 U/L,respectively.There was no significant difference in Lp-PLA2 activity among 4 groups.(P=0.938).3.There was no significant difference in serum Lp-PLA2 activity among different groups of CAD patients(F=0.082,P=0.921),but hsCRP and WBC singnificantly increased with the increasing unstability of coronary atheromatous plaque raised(P＜0.01).4.Lp-PLA2 activity was not significantly correlated with age(r=0.030,P=0.657), SBP(r=0.052,P=0.451),DBP(r=0.018,P=0.797)and BMI(r=0.030,P=0.686).5.Lp-PLA2 activity was positively correlated with Tch(r=0.523,P＜0.001), LDLc(r=0.451,P＜0.001),apoB(r=0.567,P＜0.001),TG(r=0.315,P＜0.001), Glu(r=0.187,P=0.006)and WBC(r=0.245,P＜0.001),while it was not significantly correlated with HDLc(r=-0.079,P=0.247),apoAⅠ(r=-0.010, P=0.881),UA(r=0.090,P=0.187)and hsCRP(r=0.133,P=0.052). 【Conclusions】1.Lp-PLA2 activity in CAD patients was significantly higher than those in healthy controls(P＜0.01).2.Lp-PLA2 activity in CAD patients was not significantly associated with the severity and stability of coronary atherosclerosis.3.Lp-PLA2 activity is significantly positively correlated with Tch,LDLc,apoB, TG,Glu and WBC,but it has no significant correlation with age,SBP,DBP,BMI, HDLc,apoAⅠ,UA and hsCRP.