A Study Of The Correlation Between Paraoxonase-1 And Calcified Aortic Valve Disease

Background and ObjectivesParaoxonase-1(PON-1)participates in several vital steps of lipid metabolism which was associated to calcific aortic valve stenosis(CAVS)and few articles suggested that PON-1 in blood could inhibit the calcification of aortic valve,but did not give a detailed description.We aimed to investigate whether the PON-1 exists in aortic valve and figure out the relationship between the CAVS and the level of PON-1.Materials and MethodsA total of 118 consecutive patients with CAVS were enrolled in the study and 35 individuals without aortic valve calcification were treated as a control group.According to the maximum gradient from echocardiography results,we divided the patient group into mild stenosis group(n=39,Vmax≤300cm/s),moderate stenosis group(n=38,300cm/s<Vmax≤400cm/s)and severe stenosis group(n=41,Vmax>400cm/s).According to the number of aortic valves during the operation,patients in the case group were divided into congenital bicuspid aortic stenosis group(n=55)and tricuspid aortic stenosis group(n=63).Aortic valve tissue was obtained from the postoperative pathological specimens.One part of fresh aortic valve tissue samples were stored in the 4%Formaldehyde in half an hour and the other part in the liquid nitrogen before being transferred to the minus 80-degree refrigerator.The immunohistochemical analysis was used for qualitative detection of PON-1 and ELISA was used for quantitative detection of PON-1.Peripheral blood samples were collected and tested on fasting condition in the morning.The severity of aortic stenosis was evaluated by echocardiography.Data were collected and analyzed with the SPSS(Version19.0,IBM Company,US.).One-way anova analysis was used to compare the continuous numeric parameters of each group,whereas Chi-square test was used to compare categorical variables.Pearson correlation analysis were performed to examine the relationship between PON-1 concentration and aortic valve maximum forward velocity.Results1.The case group was significantly higher than the control group in the aspects of smoking history,low density lipoprotein cholesterol(LDL-C),aortic valve maximum forward velocity(Vmax)and the maximum gradient(P<0.05).However,in terms of high-density lipoprotein cholesterol(HDL-C)and left ventricular ejection fraction(LVEF),the case group was significantly lower than the control group(P<0.05).2.Not only we detected the PON-1 in aortic valve but noticed that the level of PON-1 of case group was significantly]ower than that of control group(p<0.001).The content of PON-1 in case group was 64.56-175.00nmol/L(124.31±19.67nmol/L),and the content of PON-1 in control group was 193.06-296.3nmol/L(243.81 ±44.21 nmol/L).There was no significant difference in PON-1 content between congenital bicuspid aortic stenosis group and tricuspid aortic stenosis group(120.56±18.18nmol/L vs 124.56±16.70 nmol/L,P=0.711).3.There was no significant difference between mild and moderate stenosis group(P= 0.592).However,the PON-1 concentration of mild and moderate stenosis group was obviously higher than that of severe stenosis group respectively(both P<0.001).4.A significantly negative correlation(R=0.55)between PON-1 and the maximum forward velocity of aortic valve was detected in the total consecutive case group.Conclusions1.PON-1 was detected in aortic valve for first time and our results suggested that its concentration in aortic valve tissue will decrease with increasing aortic valve stenosis.2.PON-1 plays a protective role in calcified aortic valve disease and if PON-1 level is significantly reduced,it indicates that the aortic valve has calcified stenosis to a certain level.