Meltem Ercan

Plasma homocysteine levels in obese and non-obese subjects with or without hypertension; its relationship with oxidative stress and copper.

OBJECTIVES The relationship between plasma total Homocysteine (tHcy) and oxidative stress and plasma levels of lipids, insulin and copper levels were investigated in obese and nonobese hypertensives. DESIGN AND METHODS Plasma tHcy levels were determined by an enzyme immunoassay method. Plasma lipid peroxidation levels were measured as thiobarbituric acid reactive substances (TBARS) by spectrophotometric methods. Plasma levels of copper and insulin were measured by atomic absorption spectrophotometer and electrochemiluminescence method, respectively. RESULTS Plasma tHcy, copper and insulin levels did not differ in nonobese hypertensives compared to nonobese normotensives. Plasma TBARS levels were significantly increased in nonobese hypertensives when compared to nonobese normotensives (p < 0.001). Plasma tHcy, TBARS, copper and fasting insulin levels were significantly higher in obese normotensives and hypertensives than in nonobese normotensives and hypertensives, respectively (for each comparison; p < 0.001). There was a significant difference in plasma tHcy, TBARS and copper levels between obese subjects with or without hypertension (for each comparison p < 0.01). The univariate analyses demonstrated a significant positive correlation between tHcy and TBARS (coefficient +/- SE, 0.411 +/- 0.115, p < 0.01) and copper (coefficient +/- SE, 0.425 +/- 0.135, p < 0.01) in obese subjects. In a multivariate regression analysis in obese subjects tHcy was positively correlated with TBARS (coefficient +/- SE, 0.480 +/- 0.155, p < 0.01) and copper (coefficient +/- SE, 0.486 +/- 0.140, p < 0.01). CONCLUSIONS We hypothesize that in the presence of other traditional risk factors, Hcy may have a permissive role in the endothelium damage even within the normal range and this role may be related to free radical generating systems. Therefore, modest elevation of plasma Hcy may causally be involved in the pathogenesis of atherosclerosis and/or cardiovascular disease.

Plasma leptin levels in obese and non-obese postmenopausal women before and after hormone replacement therapy

OBJECTIVE the aim of this study was to investigate the effect of hormone replacement therapy (HRT) on plasma leptin levels in postmenopausal women, and the relationship between the plasma leptin levels and obesity. METHODS premenopausal women with normal cycles (n=30; mean ages, 35.4+/-8.3 years) and postmenopausal women (n=45; mean ages, 49.5+/-4.7 years) were randomly selected. Women were classified as obese (BMI>27 kg/m(2)) and as non-obese (BMI<27 kg/m(2)). Blood samples were obtained from the premenopausal women at the beginning of cycle, and from the postmenopausal women before and 6 months after HRT. Plasma leptin levels were measured by radioimmunassay. RESULTS plasma leptin levels were significantly higher in premenopausal women than in postmenopausal women (18. 60+/-5.0; 3.67+/-2.44 ng/ml, respectively, P<0.001). Obese premenopausal women (n=15) had significantly higher plasma leptin levels (24. 60+/-7.81 ng/ml) in comparison with the levels of the non-obese premenopausal women (n=15; 12.50+/-4. 63 ng/ml) (P<0.001). Although there was no significant difference in the plasma leptin levels between obese (n=25) and non-obese (n=20) postmenopausal women before HRT, plasma leptin levels were significantly elevated in both obese and non-obese postmenopausal women after HRT (P<0.001), and the obese women had significantly higher plasma leptin levels than the non-obese (29.05+/-10.53; 14.78+/-6.76 ng/ml, respectively, P<0.001). CONCLUSION HRT is effective in the elevation of the plasma leptin levels in postmenopausal women, and in obese women the increase of the plasma leptin levels are more marked than the non-obese women after HRT.

Abdominal aortic aneurysm or aortic occlusive disease: role of trace element imbalance.

The nature of the relationship between atheromatous disease and degenerative aneurysm is yet to be defined. The purpose of this study was to compare tissue Fe, Cu, Zn, and thiobarbituric acid reactive substances (TBARS) levels (as a marker of lipid peroxidation) in the abdominal aorta in relation to the development of aneurysmal and occlusive disease in the infrarenal aorta. This was a prospective clinical study in an institutional referral center, in hospitalized patients. Eighty male patients who underwent surgery for abdominal aortic aneurysm (AAA) or aortic occlusive disease (AOD) were included in the study. Age, risk factors and comorbid conditions were recorded, including diabetes mellitus, hypertension, coronary artery disease, smoking, and chronic obstructive pulmonary disease. Aortic wall biopsies were collected at operation from the anterolateral section of the infrarenal aorta. Tissue Fe, Cu, Zn, and TBARS levels were determined. The mean age of the AAA group was 66.2 (56—75) years and of the AOD group 57.8 (47—72) years (p <0.001). There was a higher prevalence of hypertension in AAA patients compared to AOD patients (62.5%, 35% respectively; p <0.05). The comparison of tissue Zn levels showed no significant difference. Tissue levels of Fe, Cu, and TBARS were found to be higher in the AAA group, compared with the AOD group (p<0.001 for each). These results suggest that higher oxidative stress as a result of higher Fe and Cu levels in the AAA, compared with AOD, may be one of the contributing factors in aneurysmal formation as a result of promoted wall erosion.

Plasma and erythrocytes antioxidant status and trace element levels in proteinuric patients with moderate glomerular function

The objective of the study was to investigate the effect of moderate glomerular dysfunction on oxidative stress. We determined the plasma and erythrocyte malondialdehyde (MDA) levels, as a marker of lipid peroxidation, erythrocyte glutathione (GSH) levels and activities of GSH-Px, GSH Red and SOD as an antioxidant enzymes, and plasma trace element levels containing Fe, Cu and Zn in twenty proteinuric patients (6.8 +/- 5.1 g/day) with moderate glomerular function and in 20 anemic control subjects. We found that the erythrocyte and plasma MDA levels and erythrocyte GSH-Px activities were significantly higher (p < 0.001, p < 0.001, p < 0.001, respectively) and the erythrocyte GSH levels and activities of GSH-Red and SOD activities were significantly lower (p < 0.001, p < 0.001, p < 0.001, respectively) in the patients than in the anemic subjects. Plasma Fe and Zn levels were not to be found significantly different in the patients compared to the anemic subjects. But plasma Cu levels were significantly higher in the patients (p < 0.05) when compared with the levels of anemic subjects. This study was concluded that cellular antioxidant activity decreases in proteinuric patients with moderate glomerular function. This may increase lipid peroxidation reactions by causing oxidative stress in erythrocyte membranes.

Comparison of plasma viscosity as a marker of endothelial dysfunction with nitric oxide and asymmetric dimethylarginine in subjects with dyslipidemia.

OBJECTIVE In this study, we aimed to investigate the alterations in plasma viscosity and whether there was a relationship between plasma viscosity and endothelial dysfunction markers such as nitric oxide (NOx), asymmetric dimethylarginine (ADMA) and oxidized Low Density Lipoprotein (oxLDL) in dyslipidemic subjects. MATERIAL AND METHOD 35 subjects with normolipidemia and 30 subjects with hyperlipidemia were involved in this study. Dyslipidemia was defined as total cholesterol levels ≥200 mg/dL and/or triglyceride level ≥150 mg/dL. Plasma total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, total protein, albumin levels and NOx were determined by enzymatic methods using commercial kits. Plasma ADMA concentrations and serum levels of total oxLDL were determined by ELISA. Plasma viscosity was measured by Harkness capillary viscometer. RESULT Plasma viscosity, ADMA and oxLDL values were significantly higher in subjects with dyslipidemia than in subjects with normolipidemia. Plasma NOx concentration was decreased in dyslipidemic subjects compared to the normo-lipidemic subjects. We found that fibrinogen had no effect upon plasma viscosity in selected patients with dyslipidemia. CONCLUSION Our results demonstrated that the rheological impairment of dyslipidemic patients was related with endothelial dysfunction and this was a possible cause of both micro and macrovascular complications. Therefore, as plasma viscosity is also a sensitive parameter, it can add useful information about the diagnosis and treatment of various disorders, and it should be utilized more frequently in clinical medicine.

The Altered Hemorheologic Parameters in Thromboangiitis Obliterans: A New Insight

The hemorheologic abnormalities were studied in patients suffering from thromboangiitis obliterans (TAO) and compared findings with those of patients suffering from critical limb ischemia because of peripheral atherosclerotic obstructive disease (PAOD) and the healthy subjects. This prospective study included 20 patients with TAO, 20 patients with PAOD, and 20 healthy subjects. Hematocrit, plasma fibrinogen, red blood cell rigidity, and blood and plasma viscosity were determined in all groups. Hematocrit values of the TAO group were significantly higher than those of the PAOD group and the control group (p<0.001 and p<0.001, respectively). BV at a shear rate of 6.00 sec-1 was higher in TAO than the PAOD and control (p<0.01 and p<0.05, respectively). BV at a shear rate of 225 sec-1 was higher in the TAO and PAOD than the control (p<0.001 and p<0.001, respectively) and also PAOD values were higher than the TAO (p<0.05). RBC rigidity was higher in the TAO and PAOD than the control (p<0.001 and p<0.05, respectively) and these values were higher in PAOD than the TAO (p<0.05). These results show the impairment in hemorheologic parameters in TAO may provide a new insight into the treatment of patients with TAO in the active period of the disease.

The evaluation of plasma viscosity and endothelial dysfunction in smoking individuals.

BACKGROUND Smoking is considered to be one the of risk factors effecting atherosclerosis which is associated the physical forces, biological and chemical stimuli occuring in vessel wall. The aim of this study is analysis of the biomechanical (plasma viscosity) and biochemical effect (nitric oxide, NOx; asymmetric dimethylarginine, ADMA) of smoking on endothelial function. METHODS One hundred-twenty two individuals were divided into three groups according to their smoking status. Plasma viscosity was measured by Harkness Capillary Viscometer. Plasma NOx level was determined by enzymatic methods using commercial kits. ADMA concentration was determined by Elisa Plasma Assay and and physiologic spirometric and arterial gas parameters and pulmonary blood flow rate (PBFR) were measured. RESULTS Viscosity variables of former smokers were significantly higher than those of non-smokers (p < 0.001). NOx levels were found to be statistically significantly higher when compared with current smokers and non-smokers (p < 0.001), and former smokers and non-smokers (p < 0.05). There was a higher fibrinogen levels in current smokers (p < 0.05) than smokers. CONCLUSIONS Smoking increases the plasma viscosity that may lead endothelial damage. Plasma viscosity plays an important role as a biophysical mechanical marker on the behalf of hemodynamics. Biochemical markers, NOx and ADMA may show this damage, however, we observed that plasma viscosity can be consistent with biochemical markers. Thus, plasma viscosity may be useful for diagnosis, treatment and follow-up of the patients.

Effects of cigarette smoking on hemorheologic parameters, plasma osmolality and lung function

BACKGROUND Cigarette smoking deteriorates human health via vascular disorders, cancer and especially respiratory diseases. The aim of this study is to investigate effects of cigarette smoking on hemorheologic parameters, plasma osmolality and lung function in individuals without diagnosis of chronic obstructive pulmonary disease (COPD). METHODS Patients diagnosed without COPD utilizing respiratory function test were enrolled in the study with three groups, ex-smokers (n = 21), current-smokers (n = 35) and never-smokers (n = 43). Hemorheologic parameters and plasma osmolality were measured in hemorheology laboratory. SPSS 17.0 was used for statistical analysis. RESULTS Blood and plasma viscosity, fibrinogen and hematocrit levels, mean corpuscular volume and mean corpuscular hemoglobin concentration were significantly elevated in ex-smokers and current-smokers compared to never-smokers. The standardized red blood cell deformability and oxygen delivery index and lung function were statistically lower in current-smokers than never-smokers. Pulmonary blood flow rate was statistically lower in current-smokers and ex-smokers than never-smokers. Plasma osmolality was statistically significantly higher in ex-smokers and current-smokers than never-smokers. CONCLUSIONS Our findings clearly show that cigarette smoking has severe effects on hemorheologic parameters, plasma osmolality and lung function even in individuals without COPD. Blood and plasma viscosity with plasma osmolality might be useful markers to detect early hemorheologic-hemodynamic alterations in cigarette smokers.

The Effect of β-Glucan on Trace Element Levels in Intra-Abdominal Sepsis in Rats

Sepsis is associated with the development of progressive damage in multiple organ systems. The beneficial effect of glucans has been attributed to modulation of immune function and enhances defense against bacterial, viral, fungal, and parasitic infections. The aim of this study was to investigate the putative protective effect of ß-glucan on changes of trace element levels in various tissues after experimental sepsis in rats. Sepsis was induced by cecal ligation and perforation (CLP) in 28 male Wistar albino rats. To evaluate this, rats were divided into four groups as sham operated, ß-glucan treated sham operated, CLP, and ß-glucan-treated CLP. Sixteen hours after operation, rats were decapitated and zinc (Zn) and copper (Cu) levels were determined in the liver, kidney, heart, diaphragm, and lung tissues. The results demonstrate that sepsis significantly decreased zinc and copper levels of all tissues. The decrease in tissue zinc and copper levels demonstrates the role of trace elements in sepsis-induced tissue damage. Our results indicated that ß-glucan administration did not return the zinc and copper levels to the control group level, and it seems likely that the given dose of ß-glucan was insufficient to prevent sepsis-induced organ injury.

Blood viscosity as a forgotten factor and its effect on pulmonary flow

BackgroundThe effect of smoking on blood viscosity is widely known. There are, however, few studies on the effect of blood viscosity on pulmonary circulation.MethodsWe aimed to observe the relationship between blood viscosity and pulmonary circulation among smokers and non-smokers. The study comprised 114 subjects in three groups: group 1, ex-smokers; group 2, smoked at least 10 packs/year and still smoking; group 3, never smoked. Blood viscosity (BV), pulmonary blood flow (PBF), and right ventricular systolic pressure (RVSP) were measured in all subjects.ResultsPBF was significantly lower in group 1 compared with group 3 (p < 0.05). BV in group 1 was significantly higher than group 3 (p < 0.05) while BV in group 2 was significantly higher than group 3 (p < 0.05). PBF in group 2 was significantly lower than group 3 (p = 0.01).ConclusionsWe believe that BV is a significant and forgotten factor that plays an important role in pulmonary and cardiovascular diseases. BV may affect PF even during the course of smoking, and before the clinical onset of chronic obstructive pulmonary disease (COPD). Therefore, individuals at risk of pulmonary hypertension could be detected earlier with a simple blood test.