Comparison of the relationship between age and serum paraoxonase /arylesterase activity of patients diagnosed with acute coronary syndrome in emergency department

Introduction and Objective: HDL cholesterol, which is a modifiable risk factor, is involved in prevention of formation of occlusive plaques and its antioxidant property is attributed to paraoxonase enzyme. Studies have proven the antioxidant and atheroprotective effects of paraoxonase/arylesterase (PON1), which is dependent on HDL cholesterol, preventing oxidation of LDL cholesterol and the effects of this enzyme in coronary artery disease (CAD). It has been reported that PON1 activity, which is a biomarker in many diseases, decreases in atherosclerotic diseases and with aging. Activity of PON1, which decreases with increasing age, has not yet been compared between acute coronary syndrome (ACS) patients and healthy volunteers in different age groups. In this study, we specifically targeted individuals in the young age group below 50 years of age. We investigated the relationship between acute myocardial infarction and PON1 activity and its phenotypes by comparing patients with a diagnosis of ACS presenting to emergency department and healthy volunteers. Thus, we aimed to shed light on further studies that will investigate if PON1 could be used in the diagnosis, tretment and prognosis of ACS and the efficiency of PON1 as a screening test. Material and Method: Two hundred fifteen patients aged above 18 years who presented to Bezmialem Vakıf Univesity, Faculty of Medicine, Emergency Department between October 2019 – November 2020 with chest pain and who were evaluated at emergency red area with a prediagnosis of ACS and 80 healthy volunteers who were not using any medication, were included in the study. In this prospectively designed study, the data of 118 patients who met the inclusion criteria and whose CAD was proven with angiography as >50% stenosis or total occlusion and 80 controls were noted and compared. Before initiating tratment after the first electrocardiogram in the patients who were suspected of having ACS, blood samples were obtained. Routine biochemistry tests, lipid profile and PON1 enzyme activity and phenotype distribution were studied in the blood samples obtained from the healthy volunteers and patients. The patients' ages, sexes, histories of coronary angiography, histories of cardiac by-pass operation, familial histories, comorbidities, medications used and smoking states were evaluated and noted on the demographic data form. All data analyses were performed using SPSS 21.0 and MedCalc package programs and a p value of <0,05 was considered statistically significant. Results: Of the 216 patients who presented to the emergency department with chest pain, 118 were considered eligible for the study. The data of 118 patients, who presented to emergency department with chest pain, hospitalized in coronary ICU with a prediagnosis of ACS and whose CAD was proven with coronary angiography, and the data of 80 healthy controls were examined. In the study population, 25 (21.2%) patients were female and 93 (78.8%) were male. The mean age of the patient group was calculated to be 58.61±11.31 years. In the healthy group, 29 subjects were female (36.3%) and 61 (63.7%) were male. The mean age of the volunteers was found to be 49.98±12.14 years. A statistically significant difference was found between the two groups in terms of age and sex (p<0.001, p=0.020, respectively). The median paraoxonase and arylesterase levels were compared between the patients and healthy controls to evaluate PON1 enzyme activity and a statistically significant difference was not found (p>0.05). In the patient group, a correlation was not observed between the paraoxonase and arylesterase levels and troponin. The patients were divided into two groups as under 50 years old (group A) and over 50 years old (group B). PON1 activity was evaluated according to the age groups, the median paraoxonase and arylestease values were compared and a statistically significant differece could not be found (p>0.05). PON1 acitivites were compared between 26 patients and 47 healthy control who were aged below 50 years and a significant difference could not be found (p>0.05). The mean LDL level was found to be 141.74±36.46 mg/dL in the patient group and 130.91±33.49 mg/dL in the control group and the difference was found to be statistically significant (p=0.037). When three different phenotypes of PON1 were examined in the patient and control groups, it was found that phenotype1 (PON1192QQ) was the most common phenotype [patient group: n=41 (34.7%), control group: 39 (48.8%)]. However, a statistical significance was not found in pheotype distribution (p>0.05). The number of occluded vessels (single vessel: n=65, double vessel : n=28, triple vessels: n=25) and phenotypic distribution were examined in the patient group and a statistical significance was not found between the groups (p>0.05). When the phenotypic distribution was examined in the patients aged above 50 years, phenotype1 was found with a rate of 95.1%, phenotype2 was found with a rate of 70%, phenotype3 was found with a rate of 63.6% and the difference was statistically significant (p=0.006). Conclusion: In our study in which PON1 activity in ACS was examined, the patient and control groups were compared between the young patients and young healthy controls aged below 50 years. Accordingly, it was observed that old age did not affect paraoxonase/arylesterase activity. In addition, Q/R polymorphism of PON1 was examined in our study and a significant relationship was not observed between phenotype distribution and severity of CAD. Studies have shown that the R allele did not provide favourable protection against lipid oxidation. According to the significant result obtained in the phenotype distribution in ACS patients aged above 50 years in our study, it was concluded that the RR phenotype indicated tendency to atherosclerosis at a young age, but this result by itself did not prove this tendency. We could not find clear evidence indicating efficiency of PON1 activity and genotype distribution in the diagnosis of ACS and risk classification or the relationship of PON1 activity and genotype distribution with atherosclerosis. Key Words: Paraoxonase, Arylesterase, Acute Coronary Syndrome, PON, Age