Mustafa Gür

Paraoxonase and arylesterase activities in coronary artery disease.

Background  Paraoxonase‐1 is an enzyme with three activities which are inversely related to cardiovascular diseases. Accordingly, the aim of the study was to investigate the paraoxonase, arylesterase activities and oxidative/anti‐oxidative status in coronary artery disease (CAD) and their correlation with the extent of CAD.

DNA damage in metabolic syndrome and its association with antioxidative and oxidative measurements.

The purpose of this study was to assess DNA damage levels in subjects with metabolic syndrome (MetS). Sixty‐five subjects with MetS and 65 controls were enrolled in this study. Levels of DNA damage, total antioxidant capacity (TAC), total peroxide and oxidative stress index (OSI) were measured. We found that DNA damage levels were significantly increased [155.5 (60–264) vs. 93.2 (0–208) arbitrary units; p < 0.001] and TAC levels were significantly decreased in MetS than in control (1.34 ± 0.27 vs. 55 ± 0.33 mmol Trolox equivalent/l; p < 0.001). A significant falling trend in TAC levels and a significant rising trend in DNA damage values with the increase in the number of metabolic disturbances (anova p < 0.001 for both) were observed. Total peroxide (30.9 ± 4.9 vs. 21.3 ± 2.5 μmol H2O2/l; p < 0.001) and OSI levels [2.4 (1.3–3.8) vs. 1.4 (0.7–2.3) arbitrary units; p < 0.001] were significantly higher in the subjects with MetS than in controls. We found significant negative correlation between DNA damage and TAC levels in MetS (r = −0.656, p < 0.001) and in control (r = −0.546, p < 0.001). In multiple linear regression analysis, age, body mass index, presence of MetS and number of the componens of MetS were independent predictors of log‐transformed DNA damage (p < 0.05, for all). DNA damage is increased in patients with MetS. The increase in DNA damage might be occur because of the increase in the imbalance between the production of oxidants and antioxidant defences in subjects with MetS.

The association of serum prolidase activity with the presence and severity of coronary artery disease.

ObjectivesProlidase is a cytosolic exopeptidase that cleaves iminodipeptides with carboxy-terminal proline or hydroxyproline and plays major role in collagen turnover. Collagen is the essential content in atherosclerotic plaque playing a key role in the stability/instability of and progression of coronary artery disease (CAD). Consequently, in this study we sought to determine serum prolidase activity and markers of oxidative stress such as lipid hydroperoxide and total free sulfhydryl in CAD. Design and methodsWe have evaluated 199 patients with CAD and 122 control cases with clinical, electrocardiographic, and laboratory investigation. We have measured serum prolidase activity and serum total free sulfhydryl levels spectrophotometrically. Serum lipid hydroperoxide levels were determined with ferrous ion oxidation-xylenol orange method. We assessed the association of serum prolidase activity with the presence and severity of CAD and clinical characteristics, and laboratory parameters. ResultsSerum prolidase activity (52.5±5.6 vs. 46.7±5.1 U/l, respectively, P<0.001) and serum lipid hydroperoxide levels were significantly increased in patients with CAD compared with control cases whereas, serum total free sulfhydryl levels were significantly decreased in patients with CAD compared with control cases. Serum prolidase activity and total free sulfhydryl levels were independent predictors of the presence of CAD [(χ2=75.532, ß=0.212, P=0.003) and (χ2=25.969, ß=−30.486, P=0.019), respectively] and Gensini score [(&bgr;=0.276, P<0.001) and (&bgr;=−0.274, P<0.001), respectively]. Independent predictors of serum prolidase activity were serum high-density lipoprotein cholesterol (&bgr;=−0.138, P=0.023) and urea levels (&bgr;=0.146, P=0.036), and Gensini score (&bgr;=0.317, P<0.001). ConclusionFindings of this study have shown that serum prolidase activity is significantly associated with the presence and severity of CAD, and elevated serum prolidase activity might be an independent predictor of coronary atherosclerosis.

Neutrophil to Lymphocyte Ratio Is Associated With the Severity of Coronary Artery Disease in Patients With ST-Segment Elevation Myocardial Infarction

We assessed the relationship between the severity of coronary artery disease assessed by SYNTAX score (SS) and neutrophil to lymphocyte ratio (N:L ratio) in patients with ST elevation myocardial infarction (STEMI). In total, 840 patients with STEMI in whom primary percutaneous coronary intervention was performed were prospectively included (622 male, 218 female; mean age 58.6 ± 12.4 years). Total and differential leukocyte counts and other biochemical markers were measured at admission. Patients were categorized into tertiles on the basis of SS. The N:L ratio of SShigh group was higher compared with SSlow and SSmid groups (P < .001 for all). Multivariate regression analysis showed that N:L ratio (β = .277, P < .001), ejection fraction (β = −.086, P = .012), age (β = .104, P = .004), and diabetes (β = .152, P < .001) were the independent predictors for SS in patients with STEMI.

Association of serum uric acid level and coronary blood flow.

ObjectivesSlow coronary flow (SCF) has long since been identified and endothelial dysfunction and atherosclerosis of the epicardial coronary arteries and microvasculature are reported to be associated with SCF. Serum uric acid is an independent biochemical marker of atherosclerosis, oxidative stress and endothelial dysfunction. Consequently, we aimed to investigate the association between coronary blood flow and serum uric acid level by means of thrombolysis in myocardial infarction frame count (TFC) and other laboratory parameters, in patients with SCF compared with control participants. MethodsSixty-four patients with SCF and 369 control participants with normal coronary flow were studied after quantifying coronary blood flow according to TFC. Serum uric acid levels were determined using commercially available assay kits. The association between TFC and serum uric acid level and other clinical and laboratory parameters were evaluated. ResultsStatistically significant differences were present between SCF and control groups with respect to serum uric acid, and hemoglobin levels, heart rate, cigarette smoking and sex (P<0.05 for all). The mean TFC was significantly correlated with serum uric acid, urea, creatinine, high-density lipoprotein-cholesterol and hemoglobin levels, platelet count, male gender, cigarette smoking, heart rate and systolic blood pressure (P<0.05 for all). Serum uric acid level (χ2=22.86, &bgr;=0.54, P<0.001), heart rate (χ2=7.42, &bgr;=−0.034, P=0.032) and cigarette smoking (χ2=12.343, &bgr;=0.969, P=0.025) were independent predictors of SCF, whereas serum uric acid level was the only independent predictor of the mean TFC (&bgr;=0.298, P<0.001). ConclusionsThese findings have shown that serum uric acid level is significantly associated with coronary blood flow and that elevated uric acid might be an independent predictor for the presence of SCF.

Uric acid and high sensitive C-reactive protein are associated with subclinical thoracic aortic atherosclerosis

BACKGROUND AND PURPOSE The detection of atherosclerotic lesions in the aorta by transesophageal echocardiography (TEE) is a marker of diffuse atherosclerotic disease. Hyperuricemia is a well-recognized risk factor for cardiovascular diseases. However, no data are available concerning the relationship between serum uric acid (UA) and subclinical thoracic aortic atherosclerosis. We aimed to investigate the association between thoracic aortic atherosclerosis and serum UA level. METHODS We studied 181 patients (mean age 46.3 ± 8 years) who underwent TEE for various indications. Four different grades were determined according to intima-media thickness (IMT) of thoracic aorta. UA and other biochemical markers were measured with an automated chemistry analyzer. RESULTS TEE evaluation characterized thoracic aortic intimal morphology as Grade 1 in 69 patients, Grade 2 in 52 patients, Grade 3 in 31 patients, and Grade 4 in 29 patients. The highest UA level was observed in patients with Grade 4 IMT when compared with Grade 1 and 2 IMT groups (p<0.001 and p=0.014, respectively). UA levels in patients with Grade 3 and Grade 2 IMT were also higher than patients with Grade 1 IMT group (p<0.001, for all). In multiple linear regression analysis, IMT was independently associated with UA level (β=0.350, p<0.001), age (β=0.219, p=0.001), total cholesterol (β=-0.212, p=0.031), low-density lipoprotein cholesterol (β=0.350, p=0.001), and high sensitivity C-reactive protein (hsCRP) levels (β=0.148, p=0.014). CONCLUSION Uric acid and hsCRP levels are independently and positively associated with subclinical thoracic atherosclerosis.

Contrast-Induced Nephropathy in Patients With ST Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

We assessed the relationship between contrast-induced nephropathy (CIN) and SYNTAX score (SS) and serum uric acid (SUA) levels in patients with ST elevation myocardial infarction (STEMI). A total of 835 STEMI patients in whom primary percutaneous coronary intervention was performed in our cardiology clinic were included in this study (615 male, 220 female; mean age 58.1 ± 12.2 years). The patients were divided into 2 groups (CIN and non-CIN). Contrast-induced nephropathy was observed in 9.6% (80) of patients; SS (13.9 ± 6.2/22.1 ± 5.8) and SUA (5.1 ± 0.9/6.2 ± 0.9) values in the CIN group were higher compared with the non-CIN group (P < .001, for all). All SS (95% confidence interval [CI] = 1.136-1.250, P = .001), SUA (95% CI = 1.877-3.236, P = .002), and diabetes (95% CI = 0.998-1.039, P = .026) were independent predictors of CIN in logistic regression analysis. Procedures that can prevent CIN may be beneficial in patients at high risk as identified by the SS and SUA levels.

Mean platelet volume and extent and complexity of coronary artery disease in diabetic and nondiabetic patients with ST elevation myocardial infarction.

We investigated whether the mean platelet volume (MPV) is associated with the extent and complexity of coronary artery disease in patients with ST elevation myocardial infarction (STEMI). We prospectively included 912 STEMI patients (663 male and 249 female; mean age 58.7 ± 12.4 years) who underwent primary percutaneous coronary intervention. The patients were divided into 3 groups according to MPV tertiles. Highest SYNTAX score (SS) was observed in MPVhigh group compared with MPVmid and MPVlow groups (P < .001 for all). The SS of MPVmid group was higher than MPVlow group (P = .036). The MPV in diabetic STEMI patients was higher than in nondiabetic STEMI patients (P < .001). Multivariate linear regression analysis showed that the MPV was associated with diabetes (β = .115, P = .001), troponin level (β = .131, P = .001), platelet count (β = −.241, P < .001), and SS (β = .216, P < .001). The relation between MPV and SS in diabetic STEMI patients was stronger than for nondiabetic STEMI patients (r = .473, P < .001 vs r = .129, P = .001).

Relation of serum uric acid levels with the presence and severity of angiographic coronary artery disease.

The aim of this study is to investigate the association between uric acid level and severity of coronary artery disease. Consecutive 495 patients with coronary artery disease and 356 individuals with normal coronary angiograms were included in the study. Severity of coronary artery disease was evaluated using the Gensini score index. For both groups, conventional risk factors, the levels of uric acid, and other biochemical markers were assessed. The mean uric acid levels of the patient group were significantly higher than those of the control group (P = .002). Mean uric acid levels were higher in men than in women (P < .001). In the coronary artery disease group, there was no significant correlation between uric acid levels and Gensini score in both sexes. Thus, it can be concluded that uric acid level is associated with the presence but not with the severity of coronary artery disease.

Paraoxonase and arylesterase activities in untreated dipper and non-dipper hypertensive patients

OBJECTIVES Paraoxonase, a high density lipoprotein (HDL) associated enzyme, was shown to be reduced in patients with cardiovascular diseases. We aimed to examine serum paraoxonase and arylesterase activities, and oxidative stress markers such as lipid hydroperoxide (LOOH) and total antioxidant status (TAS) in dipper and non-dipper hypertensive patients. DESIGN AND METHODS Forty-six non-dipper hypertensives (NDH group), 40 dipper hypertensives (DH group) and 28 healthy control subjects were included in the study. Clinical and echocardiographic assessment and ambulatory blood pressure monitoring were performed in all subjects. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. LOOH levels were measured by ferrous oxidation with xylenol orange assay. TAS was determined by using an automated measurement method. RESULTS Paraoxonase and arylesterase activities and TAS levels were significantly lower in patients with NDH compared to both DH and control groups (p<0.001, for both). Also, LOOH levels were found at high level in patients with NDH compared to control and DH groups. In NDH group, both paraoxonase and arylesterase activities were independently correlated with LDL cholesterol, TAS and LOOH levels. In DH group, both paraoxonase and arylesterase activities were independently correlated with HDL cholesterol and LOOH levels. CONCLUSIONS Reduced paraoxonase and arylesterase activities in NDH might indicate increased oxidative stress, which plays an important role in the development of cardiovascular diseases. Low serum activities of paraoxonase and arylesterase might be considered as prospective prognostic markers of the development of cardiovascular diseases in dipper and non-dipper hypertensive patients.