Recep Demirbag

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.

The association of total antioxidant capacity with sex hormones

Objective Although sex hormones have potential cardioprotective effects, their effects on total antioxidant capacity (TAC) are not very well known. The aim of the study was to evaluate TAC in men who have decreased and normal testosterone levels and in women in menopausal and premenopausal period. Design Ninety-seven subjects with similar age intervals, men aged <45 years and female aged <50 years, were divided into four groups: 1) 10 men with normal testosterone levels, as control, 2) 36 men with decreased testosterone, 3) 19 women in menopause, surgically induced, and 4) 32 women in premenopausal period. Testosterone and estrogen levels were measured by chemiluminescence assay and TAC were measured by using a more recently developed automated measurement method. Results The TAC was significantly lower in Group 2 and Group 3 than those of Group 1 and Group 4 (ANOVA, p<0.001). A strong correlation between TAC, and testosterone and estrogen were found (r=0.807, p<0.001; r=0.685, p<0.001, testosterone and estrogen respectively). Conclusions The observed relationship between sex hormones and TAC may have a role in mechanism of their cardioprotective effect.

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.

The inverse relationship between thoracic aortic intima media thickness and testosterone level.

Background: It is known that testosterone prevents coronary artery disease, and lower testosterone level is a risk factor for ischemic heart disease in men. However, there is no report showing the relationship between testosterone level and severity of thoracic aortic atherosclerosis. Aim: To investigate whether a relationship exists between atherosclerotic thoracic aortic intima media thickness (TAIT) and testosterone level. Method: Forty-two male patients (mean age 56 6 12 years) without a history of atherosclerotic cardiovascular disease referred for transesophageal echocardiography (TEE) were included. Intima media thickness of aorta was evaluated in each patient by using TEE. Testosterone levels were measured using a commercial kit. Blood chemistry parameters were measured by automated analyzers. The data obtained was evaluated by using correlation analyses and linear regression analysis tests. Results: Mean testosterone values were 507 6 209 ng/dl. Testosterone levels showed a negative significant correlation with TAIT (r = 2765, p < 0.001). In addition, testosterone levels showed positive correlations with albumin (r = 0.690, p = 0.019) and negative correlations with uric acid (r = 20.630, p < 0.001), HsCRP (r = 20.449, p = 0.003), fibrinogen (r = 20.508, p = 0.001), and white blood cells (r = 20.433, p = 0.005). On the other hand, multiple linear regression analysis showed that TAIT was independently associated with testosterone and uric acid (β = 20.610, p = 0.002 versus β = 0.409, p = 0.026 respectively) Conclusion: This study indicates that there is an independent relationship between testosterone and TAIT.

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.

Unidirectional communication between the circumflex and right coronary arteries: a very rare coronary anomaly and cause of ischemia

Intercoronary communication is an exceptionally rare congenital malformation. A 43-year-old male was admitted to our cardiology department with symptomatic stable angina. ECG and echocardiography was normal. Exercise electrocardiography showed ST depression in inferior leads. No atherosclerotic plaque in the coronary arteries was detected on coronary angiography. However, a unidirectional intercoronary communication between the circumflex and right coronary arteries, which was leading a coronary steal from right to left, was observed. Although intercoronary communication is generally not related with ischemia, ischemic symptoms and exercise ECG changes of this case suggested that unidirectional flow might cause myocardial ischemia via coronary steal. Consequently, intercoronary communication, a very rare coronary anomaly and a cause of ischemia, is discussed in this case report.

The association of elasticity indexes of ascending aorta and the presence and the severity of coronary artery disease

ObjectivesTo investigate the association between elasticity indexes of aorta and severity of coronary artery disease (CAD) in patients with stable CAD. MethodsFifty-six patients with CAD (CAD group) and 40 patients without CAD [non CAD (NCAD group)] were included in the study. Ascending aorta (Ao) diameters (mm) and Ao elastic indexes namely, Ao strain (AS), Ao distensibility (AD) were calculated from the echocardiographically derived Ao diameters and hemodynamic pressure measurements in all patients. Coronary angiography was performed in both CAD and NCAD groups. Severity of CAD was evaluated by using Gensini score index. ResultsMean AD and AS measurements of CAD group were lower than that of NCAD group (P<0.001, for both). In CAD group, both AD and AS were associated with mean arterial blood pressure, presence of hypertension, Gensini score, left ventricle mass index, sex, and triglyceride levels in bivariate analysis (P<0.05, for all). CAD groups both AD (&bgr;=−0.577, P=0.003) and AS (&bgr;=−0.494, P=0.021) were independently correlated with Gensini score in multiple linear regression analysis. The AD values of ≥1.24 predict presence of low Gensini score (≤26 for this study) with sensitivity of 88.2% and specificity of 84.6% with area under the curve of 0.94; whereas the AS values of ≥3.36 predict presence of low Gensini score with sensitivity of 82.4% and specificity of 87.2% with area under the curve of 0.873. ConclusionFindings of this study have shown that AD and AS were independently associated with severity of CAD and that impaired elasticity indexes of the aorta might be independent predictors for the severity of coronary atherosclerosis.