Effects of atorvastatin on reactive hyperemia and inflammatory process in patients with congestive heart failure

Purpose of the study was to investigate whether short-term atorvastatin treatment improves endothelial function and affects inflammatory process in patients with heart failure (HF) and normal cholesterol levels. HF is characterized by endothelial dysfunction and increased inflammatory process, while statins restore endothelial function having also anti-inflammatory effects in hypercholesterolemic patients. We investigated the effect of 4-week atorvastatin treatment (10 mg/day) on endothelial function and inflammatory markers in patients with HF and cholesterol levels <220 mg/dl. Patients were randomly allocated into groups and received atorvastatin (n=19) or no statin (n=19). Forearm blood flow was measured using gauge-strain plethysmography. Serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and soluble vascular cell adhesion molecule (sVCAM-1) were determined with ELISA. Data are expressed as median [25th-75th percentile]. Forearm vasodilatory response to reactive hyperemia was significantly improved in atorvastatin-treated patients (from 38.1% [32.0-59.1] to 70.0% [61.1-106.3], P<0.01), while it remained unaffected in the control group. Levels of IL-6, TNF-alpha and sVCAM-1 were decreased in atorvastatin-treated group (from 7.8 pg/ml [4.8-9.5], 3.2 pg/ml [2.7-4.8] and 595 ng/ml [440-810] to 5.6 pg/ml [2.5-9.0], 2.8 pg/ml [2.0-3.6] and 289 ng/ml [169-368], respectively, P<0.05 for all) but not in the control group. These findings indicate that atorvastatin may improve forearm vasodilatory response to reactive hyperemia and depress inflammatory process in patients with heart failure and normal baseline cholesterol levels.     

Endothelial function and proinflammatory cytokines in patients with ischemic heart disease and dilated cardiomyopathy

BACKGROUND: Proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) are important mediators of immune response, associated with endothelial dysfunction in patients with coronary artery disease (CAD) or heart failure. We compared endothelial function and levels of IL-6 and TNF-alpha between patients with ischemic heart failure, dilated cardiomyopathy, CAD and healthy controls. METHODS: The population consisted of 20 patients with dilated cardiomyopathy, 48 patients with ischemic cardiomyopathy, 26 patients with CAD and normal left ventricle function and 14 healthy controls. Forearm blood flow was measured using venous occlusion strain gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to nitrate were considered as indexes of endothelium-dependent and endothelium-independent dilation, respectively. RESULTS: Levels of IL-6 were significantly higher in ischemic cardiomyopathy compared to CAD patients (P<0.05) or controls (P<0.05) and in patients with dilated cardiomyopathy compared to controls (P<0.05). TNF-alpha levels were significantly higher in both groups with ischemic or dilated cardiomyopathy compared to CAD (P<0.05) or controls (P<0.05). RH% was significantly lower in ischemic and dilated cardiomyopathy compared to CAD (P<0.05) or controls (P<0.001) and higher in dilated than ischemic cardiomyopathy (P<0.05). CONCLUSIONS: Impaired endothelial function and increased inflammatory process were found in both types of heart failure. A greater endothelial dysfunction was observed in patients with ischemic heart failure compared to those with dilated cardiomyopathy, implying that the underlying atherosclerosis may participate in this process.     

Effects of combined administration of low dose atorvastatin and vitamin E on inflammatory markers and endothelial function in patients with heart failure

BACKGROUND: Heart failure has been associated with impaired endothelial function, increased inflammatory process and elevated oxidative stress status. Both statins and vitamin E separately improve endothelial function in patients with hypercholesterolemia and/or advanced atherosclerosis. AIM: To evaluate the effect of atorvastatin alone or in combination with vitamin E on endothelial function and serum levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha) and vascular cells adhesion molecule (sVCAM-1) in patients with ischemic heart failure. METHODS: Thirty-eight male patients with ischemic cardiomyopathy were randomly divided into three groups and received either atorvastatin 10 mg/day (n = 14), a combination of atorvastatin 10 mg/day plus vitamin E 400 IU/day (n = 12), or no statin or antioxidant treatment (n=12, controls) for 4 weeks. Forearm blood flow (FBF) was measured using venous occlusion strain-gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to nitrate (NTG%) was defined as the percent change of FBF from rest to the maximum flow during reactive hyperemia or after nitrate administration, respectively. RESULTS: RH% was significantly improved in both the atorvastatin-treated (p < 0.01) and atorvastatin plus vitamin E groups (p < 0.05), but the increase was significantly higher in the atorvastatin-treated group (p < 0.05). Serum levels of IL-6, TNF-alpha and sVCAM-1 were decreased in the atorvastatin-treated group (p < 0.05 for all), but remained unaffected in the other two groups (p = NS for all). CONCLUSIONS: Low dose atorvastatin treatment improves endothelial function and reduces the expression of proinflammatory cytokines and adhesion molecules in patients with ischemic heart failure, an effect partly depressed by vitamin E.     

Effects of insulin dependence on inflammatory process, thrombotic mechanisms and endothelial function, in patients with type 2 diabetes mellitus and coronary atherosclerosis

BACKGROUND: Type 2 diabetes mellitus (T2DM) is characterized by endothelial dysfunction, increased thrombogenicity and abnormal inflammatory response. HYPOTHESIS: We hypothesizsed that insulin dependence/exogenous insulin administration may affect thrombotic/inflammatory status and endothelial function in patients with T2DM and coronary artery disease (CAD). METHODS: Fifty-five patients with T2DM + CAD (26 insulin-treated (INS) and 29 under oral biguanide + sulphonylurea (TABL)) were recruited. Endothelial function was assessed by gauge-strain plethysmography, and serum levels of inflammatory and thrombotic markers were determined by enzyme linked immunosorbent assay. RESULTS: There was no significant difference in endothelium-dependent dilation (EDD) between the study groups, while EDD was correlated with fasting glucose levels in both INS (r = - 0.776, p = 0.0001) and TABL (r = - 0.702, p = 0.0001). Patients in INS group had higher levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), monocyte chemoattractant protein (MCP-1) and vascular cell adhesion molecule (sVCAM-1), compared to TABL. However, TNF-alpha was negatively correlated with protein C (PrtC) only in INS (r = - 0.726, p = 0.01) but not in TABL group (r = - 0.066, p = 0.738). Similarly, sVCAM-1 was correlated with PrtC only among INS patients (r = - 0.451, p = 0.046) but not in TABL (r = 0.069, p = 0.727). In multivariate analysis, insulin dependence was a predictor of IL-6, TNF-alpha, MCP-1 and sVCAM-1 levels independently from the patients' demographic characteristics, the angiographic extend of CAD or the duration of diabetes. CONCLUSIONS: Insulin treatment in patients with type 2 diabetes mellitus affects the expression of inflammatory cytokines and subsequently modifies the thrombotic mechanisms in patients with coronary atherosclerosis, independently from the duration of diabetes and the extend of coronary artery disease.     

Effects of combined administration of vitamins C and E on reactive hyperemia and inflammatory process in chronic smokers

Purpose of this study was to investigate the effect of combined administration of antioxidant vitamins C and E on endothelial function and serum levels of inflammatory markers such as tumor necrosis factor (TNF-), interleukines 1b (IL-1b) and 6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin in chronic smokers. Forty-three smokers were randomly divided into four groups receiving vitamin C 2 g/day (group A), vitamin C 2 g/day plus vitamin E 400 IU/day (group B), vitamin C 2 g/day plus vitamin E 800 IU/day (group C) or no antioxidant treatment (group D), for 4 weeks. Forearm blood flow (FBF) was measured using venous occlusion strain gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) was expressed as the percentage change from baseline to post reactive hyperemia blood flow. RH% was significantly increased in groups B (P<0.05) and C (P<0.01), but remained unaffected in groups A and D. Serum levels of IL-1b, IL-6, sVCAM-1 and sICAM-1 were significantly reduced in group C (P<0.05, respectively), but remained unaffected in groups A, B and D. Thus, short term administration of vitamins C (2 g/day) and E (800 IU/day) reduces serum levels of IL-1b, IL-6, sVCAM-1 and sICAM-1, and improves forearm vasodilatory response to reactive hyperemia in healthy young smokers, while monotherapy with vitamin C alone is ineffective.     

Reduced forearm reactive hyperaemia in normoalbuminuric subjects with Type 1 diabetes and retinopathy.

AIM: To determine whether the forearm vasodilatory response to reactive hyperaemia (RH) is reduced in normoalbuminuric subjects with Type 1 diabetes mellitus and retinopathy compared with subjects with no retinopathy. METHODS: Forearm RH, an indicator of endothelial function, was measured, using strain-gauge plethysmography, in 39 normoalbuminuric subjects (22 with retinopathy) with long-standing Type 1 diabetes mellitus. RESULTS: were evaluated in relation to conventional risk factors for atherosclerosis, and C-reactive protein (CRP), which we have recently determined to be an independent correlate of forearm RH. RESULTS: Forearm RH was decreased in subjects with retinopathy compared with those with no retinopathy (219 +/- 182 vs. 473 +/- 355, P < 0.01). Both retinopathy and CRP proved to be independent and negative predictors, and explain 27% of the variance, in forearm RH. CONCLUSION: Retinopathy in subjects with Type 1 diabetes mellitus may reflect a generalized process of endothelial dysfunction, even in the absence of microalbuminuria.     

Evidence for the regulation of levels of plasma adhesion molecules by proinflammatory cytokines and their soluble receptors in type 1 diabetes

OBJECTIVES: To investigate the regulation of soluble adhesion molecules by tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), and relationships with circulating cytokine receptors, in vivo, in type 1 diabetes. DESIGN: Cross-sectional study. SETTING: University hospital diabetes clinic. SUBJECTS: A total of 47 non-nephropathic, Caucasian type 1 diabetics and 39 nondiabetic controls. OUTCOME MEASURES: Plasma levels of TNF-alpha, IL-6, their soluble receptors and adhesion molecules intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), sE-selectin and von Willebrand factor (vWF), and risk factors for cardiovascular disease. RESULTS: Plasma concentrations of IL-6 were elevated in diabetic patients compared with controls [median (interquartiles) 1.28 (0.89-2.65) vs. 0.66 (0.45-1.73) pg mL(-1): P=0.016], and in these patients IL-6 and soluble IL-6 receptor (sIL-6R) levels correlated with concentrations of sICAM-1 (r = 0.41, P = 0.012 and r = 0.31, P = 0.04, respectively). Tumour necrosis factor-alpha soluble receptor-2 (sTN-FRII), but not TNF-alpha or tumour necrosis factor soluble receptor-1 (sTNFRI), was elevated in diabetic subjects (P = 0.027). Plasma TNF-alpha levels correlated with sVCAM-1 (r = 0.39, P = 0.008), triglycerides (r = 0.36, P = 0.02 1) and diastolic blood pressure (r = 0.35; P = 0.024). Both sTNFRI and sTNFRII correlated with blood pressure (r = 0.46, P = 0.002; r = 0.32, P = 0.034) and triglycerides (r = 0.33, P = 0.033; r = 0.29, P = 0.05). In contrast, HDL-cholesterol and triglyceride were related to sE-selectin (r = -0.45 and +0.45; both P < 0.001). Neither sE-selectin nor vWF were related to cytokine concentrations. Finally, both TNF-alpha and sIL-6R correlated sTNFRI and RII (r = 0.44-0.49, P < 0.001). None of these interactions were apparent in control subjects. CONCLUSIONS: (i) IL-6, through effects on sICAM-1, and TNF-alpha via effects on sVCAM-1, may promote vascular adhesion; (ii) plasma levels of TNF-alpha are associated with dyslipidaemia and increased blood pressure, adding to vascular disease risk; (iii) the actions of both cytokines are probably modified by altered production of soluble receptors in diabetic subjects.     

Endothelial dysfunction and inflammatory process in transfusion-dependent patients with beta-thalassemia major

BACKGROUND: Beta-thalassemia major is associated with increased cardiovascular risk, although the underlying mechanisms remain unclear. We examined endothelial function and serum levels of inflammatory mediators in transfusion-dependent patients with beta-thalassemia major. METHODS: The study population consisted of 67 patients with homozygous beta-thalassemia major, (aged 24.6+/-0.7 years) and 71 healthy age and sex matched controls. Forearm blood flow was measured with gauge-strain plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to nitrate (NTG%) was expressed as the percentage change of forearm blood flow from baseline to the maximum flow during reactive hyperemia or sublingual nitroglycerin, respectively. Serum levels of interleukin 6 (IL-6), soluble vascular cell adhesion molecule (sVCAM-1) and soluble intercellular adhesion molecule (sICAM-1) were determined with ELISA. RESULTS: Patients had significantly lower levels of total cholesterol (125+/-4.5 vs. 207+/-7 mg/ml, p<0.01), ApoA1 (120+/-3 vs. 129+/-5 mg/ml, p<0.05), ApoB (60.5+/-2 vs. 95+/-4 mg/ml, p<0.01), ApoE (3+/-2 vs. 4+/-0.2 mg/ml, p<0.01) and Lp(a) (7.9+/-1.3 vs. 14.5+/-3.2 mg/ml, p<0.01) than controls. IL-6 levels were significantly higher in patients (3.03+/-0.31 pg/ml) than controls (1.15+/-0.15 pg/ml, p<0.01). Similarly, sVCAM-1 and sICAM-1 levels were significantly higher in patients (513+/-31 and 368+/-25.5 ng/ml, respectively) than controls (333+/-13.8 and 272+/-14.05 ng/ml, respectively, p<0.01 for both). Maximum hyperemic forearm blood flow and RH% were lower in patients (7.1+/-0.3 ml/100 ml tissue/min and 49+/-2.8%, respectively) than controls (8.26+/-0.32 ml/100 ml tissue/min and 86.3+/-5.57%, respectively, p<0.01 for both). CONCLUSIONS: Beta-thalassemia major is associated with impaired endothelial function and increased levels of IL-6, sVCAM-1 and sICAM-1, suggesting a potential role of inflammation and endothelial dysfunction in the complications of the disease.     

Evidence of vascular dysfunction in young patients with successfully repaired coarctation of aorta

It is well documented that in patients with coarctation of the aorta life expectancy is not normal even after successful coarctation repair (SCR), primarily due to cardiovascular events. We examined endothelial function in the forearm circulation, the mechanical properties and intima/media thickness in carotid and femoral arteries and the inflammatory process in normotensive patients, after coarctation repair. Fifteen patients, 29+/-2 years old, 12+/-2.9 years after SCR and 16 age- and sex-matched controls were enrolled in our study. Forearm blood flow was determined by gauge-strain plethysmography. Forearm vasodilatory response to reactive hyperemia was expressed as the %change from baseline to post-reactive hyperemia blood flow. High resolution ultrasound was used for determination of intima/media thickness and elastic properties of carotid and femoral arteries. Serum levels of soluble vascular adhesion molecule 1 (sVCAM-1), intercellular adhesion molecule 1 (sICAM-1), E-selectin, and interleukines 1b (IL-1b) and 6 (IL-6) were determined by ELISA. Reactive hyperemia was significantly decreased in patients compared to controls (p<0.01). Patients with SCR had higher intima/media thickness and decreased distensibility in the carotid arteries than controls (p<0.01 for both). Serum levels of sICAM-1, sSVCAM-1, E-selectin and IL-1b were higher in SCR group than in controls (p<0.05 for all). Adult patients after SCR have impaired endothelial function in the forearm circulation, increased intima/media thickness, decreased distensibility in the carotid arteries and increased levels of proinflammatory cytokines and adhesion molecules than healthy controls. These results may partly explain the high incidence of coronary artery disease in patients with repaired coarctation of the aorta.     

Circulating retinol-binding protein 4 concentrations in patients with coronary artery disease and patients with type 2 diabetes mellitus

Circulating Retinol-Binding Protein 4 (RBP4) has recently been identified as a marker of insulin resistance. We tested this hypothesis in patients with coronary artery disease (CAD), patients with type 2 diabetes mellitus (T2DM), and in non-diabetic control subjects. We studied plasma RBP4 levels and RBP4-to-transthyrethin (TTR) ratio, estimating the excess circulating RBP4 in proportion to TTR, in 45 individuals divided into three groups (15 CAD, 15 T2DM, and 15 controls). Plasma RBP4 levels were significantly lower in patients with T2DM than in non-diabetic control subjects (P?=?0.05). The RBP4/TTR ratio was not statistically different between the groups. There was no difference in plasma RBP4 levels and RBP4/TTR ratio between non-diabetic CAD patients and control subjects or those with and without metabolic syndrome. No significant associations were found between RBP4 and RBP4/TTR ratio, as dependent parameters, with markers of the metabolic syndrome and lipid metabolism. RBP4 does not seem to be a valuable marker for identification of the metabolic syndrome or insulin resistance in patients with T2DM or CAD.     

The endothelial dysfunction in patients with type 2 diabetes mellitus is associated with IL-6 gene promoter polymorphism in Chinese population

The purpose of this study is to examine the effects of IL-6 gene promoter -174G/C and -572G/C polymorphism on endothelial function of Chinese T2DM and normal glucose regulation (NGR) subjects. 512 newly diagnosed T2DM patients and 483 NGR subjects were recruited and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) was performed for the IL-6 gene promoter -174G/C and -572G/C polymorphism. Flow-mediated dilation (FMD) was measured as a non-invasive indicator for endothelial function. The results show that the C allele and CC genotype at -174 of IL-6 gene promoter region was extremely rare in both T2DM and NGR groups; genotypes' and alleles' frequency at -572 of IL-6 gene promoter region is of no difference between T2DM and NGR groups; within T2DM group, higher plasma IL-6 concentration and lower FMD was found in patients with -572 GC (2.36 ± 0.69, 4.23 ± 3.82%) or GG (2.32 ± 0.74, 4.24 ± 3.67%) genotype, compared with patients with CC (2.15 ± 0.62, 5.28 ± 3.94%) genotype. The conclusion of the study is that in comparison with patients of CC genotype, the T2DM patients of -572 GC or GG genotype may have more aggravated endothelial dysfunction (ED) and be at higher risk for coronary artery disease (CAD).     

C-reactive protein levels determine systemic nitric oxide bioavailability in patients with coronary artery disease.

AIM: Elevated C-reactive protein (CRP) levels are associated with impaired endothelial vasoreactivity in patients with coronary artery disease (CAD). Because inflammatory cytokines experimentally reduce basal and stimulated endothelial nitric oxide (NO) release, we hypothesised that patients with elevated CRP-levels are characterised by a systemic impairment in NO bioavailability. METHODS AND RESULTS: Forearm blood flow (FBF) responses were measured by venous occlusion plethysmography in 75 male patients with documented CAD. Inhibition of NO synthesis by infusion of L-NMMA significantly reduced baseline FBF (2.2 +/- 0.5 vs. 1.9 +/- 0.5 mL/min/100 mL of forearm tissue, P < 0.001) and acetylcholine-stimulated FBF responses (AUC: 35.0 +/- 16.0 vs. 25.9 +/- 11.9; P < 0.001). CRP serum levels were inversely correlated with L-NMMA-induced decreases in baseline as well as acetylcholine-stimulated FBF responses. Co-infusion of the oxygen-derived free radical scavenger vitamin C significantly increased baseline FBF from 2.0 +/- 0.5 to 2.5 +/- 0.7 (mL/min/100 mL forearm tissue (P < 0.001)) and acetylcholine-stimulated FBF responses in patients with elevated CRP, but not in patients with low CRP serum levels. Vitamin C-induced increases in baseline FBF and in acetylcholine-stimulated FBF responses were significantly correlated with CRP serum levels. By multivariable analysis, CRP serum levels remained the only statistically significant independent predictor of NO bioavailability in the systemic circulation of patients with CAD. CONCLUSIONS: In patients with CAD, low grade systemic inflammation is associated with increased in vivo oxidative stress leading to impaired systemic bioavailability of NO, which might significantly contribute to the transition from stable coronary artery disease to acute coronary syndromes.     

Effects of chronic ethanol and vitamin C administration on production of tumor necrosis factor-alpha and interleukin-6 in rats

Chronic alcoholism complicated by alcoholic liver disease (ALD) is characterized by activation of inflammatory responses. Alcohol intake increases gut permeability allowing substances such as lipopolysaccharides (LPS) which are strong inducers of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) to enter the circulation. Vitamin C is an antioxidant with many cellular activities seemed to protect cells against alcohol-induced peroxidation. In present study, serum levels of TNF-alpha and IL-6 were measured by ELISA method in four groups of albino rats, each group consists of 10 rats. Group (I) was untreated group (control), group (II) was treated with ethanol, group (III) was treated with ascorbic acid and group (IV) was treated with ethanol + ascorbic acid. Results revealed that both TNF-alpha and IL-6 serum levels were very highly significantly increased in group (II) and (IV) than control group (1) (P < 0.001). Group (III) showed significantly (P < 0.001) decreased TNF-alpha serum level than group (II) and (IV) while it showed significantly (P < 0.001) increased IL-6 serum level than control group (I) and also significantly decreased IL-6 serum level than group (IV). Serum IL-6 level was significantly (P < 0.01) decreased in group (III) than (II). These results indicate that serum levels of the proinflammatory cytokines TNF-alpha and IL-6 may serve as predictive biomarkers for progression of ALD. In addition, using TNF-alpha neutralizing agent (or its antagonist)/or IL-6 as an anti-apoptotic factor could be useful as a treatment strategy of ALD.     

Inflammatory markers and IL-6 polymorphism in peripheral arterial disease with and without diabetes mellitus

Peripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis, recognized as an inflammatory disease of the vessel wall, probably accelerated by diabetes mellitus (DM). Elevated interleukin (IL)-6 levels have been associated with increased cardiovascular morbidity and a common polymorphism has been identified in the promoter region of the IL-6 gene. The aim of this prospective study was to investigate inflammatory mediators in PAD patients (+/- DM) and to investigate a possible relationship to the IL-6 gene polymorphism. Five groups of patients (DM, intermittent claudication +/- DM, critical limb ischemia (CLI) +/- DM) and a control group of 20 individuals each were included. Hemoglobin, high sensitive C-reactive protein (hsCRP), creatinine, blood lipids, white blood cells (WBC); CD11b/CD18; vascular cell adhesion molecule (sVCAM-1), intercellular adhesion molecule (sICAM-1), sE-selectin, sP-selectin; IL-6, IL-8, tumour necrosis factor (TNF)alpha, sTNFalpha-R1 and sTNFalpha-R2 were analysed. The IL-6 gene polymorphism was determined in all groups and also compared with 200 healthy controls from a larger study of blood donors. In a multiple regression analysis, adjusted for gender, smoking and age, the effect of CLI was significantly (p < 0.05) associated with elevated levels of the WBC count, hsCRP, proinflammatory cytokines (IL-6, TNFalpha-R1-2) and endothelial (sICAM, sVCAM) and WBC (CD11b gran) markers. The effect of less advanced PAD (intermittent claudication) was related to an increased concentration of sVCAM-1 and the number of monocytes and granulocytes. DM or leg ulcers were not significantly related to any of the markers. No significant difference in frequency of the various IL-6 genotypes was found between the groups or when compared with the group of 200 blood donors (p> 0.3). Activation of cytokines, endothelial cells and WBC was related to the Fontaine stage of PAD but not to the presence of DM or ulcers. No association was found between the polymorphism in the IL-6 promoter region and PAD.     

Vitamin C blocks vascular dysfunction and release of interleukin-6 induced by endothelin-1 in humans in vivo

OBJECTIVE: Inflammation of the vessel wall is of importance in atherosclerosis. Endothelin-1 (ET-1) exerts pro-inflammatory effects and contributes to endothelial dysfunction. The objective was to test whether ET-1 impairs vascular function by increasing oxidative stress and release of pro-inflammatory cytokines in humans. METHODS: Forearm blood flow (FBF) was determined in 12 young healthy males with venous occlusion plethysmography. RESULTS: Intra-brachial infusion of ET-1 (20 pmol/min) decreased both endothelium-dependent and -independent vasodilatation (P<0.001). ET-1 also increased venous IL-6 levels (0.96+/-0.14-1.40+/-0.15 ng/ml; P<0.001). Administration of Vitamin C (24 mg/min) following the ET-1 infusion did not restore vascular function. However, pre-treatment with Vitamin C before ET-1 prevented the decrease in endothelium-dependent and -independent vasodilatation as well as the increase in IL-6 levels (1.20+/-0.28 versus 1.29+/-0.27 ng/ml; P=0.57). Infusion of a control vasoconstrictor substance, noradrenaline (80 ng/min) for 30 min did not affect IL-6 levels. CONCLUSIONS: ET-1 impairs endothelium-dependent and -independent vasodilatation and stimulates release of IL-6 in humans in vivo. These effects are inhibited by pre-treatment with the antioxidant Vitamin C. This suggests that the mechanism by which ET-1 impairs vascular function and stimulates release of IL-6 involves increased oxidative stress.     

Impact of pathogen burden in patients with coronary artery disease in relation to systemic inflammation and variation in genes encoding cytokines

The number of infectious pathogens to which an individual has been exposed (pathogen burden) has been linked to the development and the prognosis of coronary artery disease (CAD). The interaction among infection, genetic host susceptibility, and CAD remains unclear. This study was aimed at evaluating the modulation of the association between CAD and pathogen burden, by serum levels of inflammatory markers and polymorphisms of the interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha genes. Immmunoglobulin (Ig) G or IgA antibodies to 8 pathogens were determined in 991 patients with CAD and 333 control subjects. Serum levels of high-sensitivity C-reactive protein, fibrinogen, IL-6, and TNF-alpha were also measured. All subjects were genotyped for the IL-6/G-174C, the TNF/C-851T, and the TNF/G-308A polymorphisms. Analysis of single pathogens demonstrated a positive relation to the presence of CAD for some (Chlamydia pneumoniae, cytomegalovirus, Helicobacter pylori, and herpes virus simplex type 1), but not all pathogens. A strong association between increasing pathogen burden and CAD was confirmed, even after adjustment for risk factors. The prevalence of a high pathogen burden (>/=4 pathogens) was 50% in patients and 21% in controls (p <0.0001). A high pathogen burden was associated with decreased high-density lipoprotein cholesterol levels (p <0.001). The association between CAD and pathogen burden was modulated by the IL6/G-174C polymorphism, the odds ratio being higher in heterozygotes than in both types of homozygotes (p <0.05). This interaction appeared to be mediated by variations in serum IL-6 levels. No such interaction was detected with any of the 2 TNF-alpha polymorphisms.     

Vitamin E supplementation reduces plasma vascular cell adhesion molecule-1 and von Willebrand factor levels and increases nitric oxide concentrations in hypercholesterolemic patients

Up-regulation of vascular cell adhesion molecule-1 (VCAM-1) and reduced nitric oxide (NO) availability represent early characteristics of atherosclerosis. To evaluate whether the antioxidant vitamin E affected the circulating levels of soluble VCAM-1 (sVCAM-1) and the plasma metabolite of NO (nitrite+nitrate) in hypercholesterolemic patients, either vitamin E (either 400 IU or 800 IU/d for 8 wk) or placebo were randomly, double-blindly given to 36 hypercholesterolemic patients and 22 age- and sex-matched controls. At baseline hypercholesterolemic patients showed higher plasma sVCAM-1 (microg.liter(-1)) (591.2 +/- 132.5 vs. 505.0 +/- 65.6, P < 0.007) and lower NO metabolite (microM) levels (15.9 +/- 3.4 vs. 29.2 +/- 5.1, P < 0.0001) than controls. In hypercholesterolemic patients, 8 wk vitamin E (but not placebo) treatment significantly decreased circulating sVCAM-1 levels (400 IU: -148.9 +/- 84.6, P < 0.009; 800 IU: -204.0 +/- 75.7, P < 0.0001; placebo: -4.7 +/- 22.6, NS), whereas it increased NO metabolite concentrations (400 IU: +4.0 +/- 1.7, P < 0.02; 800 IU: +5.5 +/- 0.8, P < 0.0001; placebo: +0.1 +/- 1.1, NS) without affecting circulating low- density lipoprotein levels. Changes in both plasma sVCAM-1 and NO metabolite levels showed a trend to significantly correlate (r = -0.515, P = 0.010; and r = 0.435, P = 0.034, respectively) with changes in vitamin E concentrations induced by vitamin E supplementation. In conclusion, isolated hypercholesterolemia both increased circulating sVCAM-1 and reduced NO metabolite concentrations. Vitamin E supplementation counteracts these alterations, thus representing a potential tool for endothelial protection in hypercholesterolemic patients.     

Endothelial nitric oxide synthase Glu298Asp (G894T) gene polymorphism in coronary artery disease patients with type 2 diabetes mellitus

AimsEndothelial dysfunction is thought to be a significant risk factor for cardiovascular disease. This study determined the role of endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism and intergenotypic variation of plasma nitric oxide (NO) levels in coronary artery disease (CAD) patients with type 2 diabetes mellitus (DM).MethodsThis case–control study included 28 documented CAD patients with type 2 DM and 32 non-diabetic patients with CAD. Fifty healthy volunteers without any major cardiovascular risk factors served as controls. NO was estimated by modified Griess method. The eNOS gene polymorphism was studied by amplifying DNA by PCR and digesting with BanII restriction enzyme. Restriction fragment length polymorphism was studied by using a gel documentation system.ResultsThe genotype frequencies for Glu298Asp (GT) genotype were 10.71% in diabetic CAD patients, 28.1% in non-diabetic CAD patients and 12% in controls. The T allele frequency was higher in the non-diabetic CAD group (14%) as compared with the diabetic CAD (5.4%) and control group (6%). NO level was significantly lower in non-diabetic CAD patients (10.25 mmol/L) but not in diabetic CAD patients (13.89 mmol/L) as compared to controls (16.78 mmol/L).ConclusionGlu298Asp polymorphism is not the mediator of increased incidence of CAD in diabetic patients.     

Adiponectin is inversely associated with renal function in type 1 diabetic patients

OBJECTIVE: Adipose tissue is a source of several adipocytokines that may contribute to vascular complications. We examined the relation of adiponectin with several cardiovascular risk factors and with micro- and macrovascular outcomes in type 1 diabetic patients. DESIGN: Cross-sectional data on 543 type 1 diabetic patients from the EURODIAB Prospective Complications Study were analyzed. We determined adiponectin, TNF-alpha, IL-6, C-reactive protein, soluble vascular cell adhesion molecule (sVCAM-1), and sE-selectin by ELISA. RESULTS: We found that adiponectin was negatively correlated with body mass index, waist to hip ratio, insulin, and fasting triglyceride, and positively with high-density lipoprotein, low-density lipoprotein, and total cholesterol, TNF-alpha, and sVCAM-1, but was not related to C-reactive protein, IL-6, and sE-selectin. Surprisingly, significantly raised concentrations of adiponectin were found with albuminuria, retinopathy, and cardiovascular diseases (for all, P < 0.0001). Adiponectin levels were inversely associated with glomerular filtration rate (GFR) (P < 0.0001). Multivariate regression models showed that the associations of adiponectin with albuminuria and GFR were independent of established risk factors. The association between adiponectin and albuminuria was attenuated by GFR, whereas the association of adiponectin with retinopathy and cardiovascular disease disappeared after adjustments for established risk factors. The association of adiponectin with sVCAM-1 was independent of established risk factors. CONCLUSION: We conclude that in type 1 diabetic patients, adiponectin is associated with impaired renal function. Adiponectin may be enhanced in type 1 diabetic patients as a physiological counterregulatory response to mitigate endothelial damage and vascular damage.     

Obesity and steatosis influence serum and hepatic inflammatory markers in chronic hepatitis C

Obesity and fatty liver are commonly observed among patients with chronic hepatitis C virus (HCV) and are risk factors for increased hepatic fibrosis. Obesity is accompanied by a low-grade, chronic inflammatory response that may contribute to pathogenesis of obesity-related comorbidities. To assess whether obesity and steatosis potentiate expression of inflammatory markers in chronic HCV, serum protein and hepatic messenger RNA (mRNA) levels of c-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were measured in 171 patients with chronic HCV. The relationships of body mass index, steatosis, histological features of inflammation and fibrosis with serum and hepatic levels of these factors were determined. In comparison with lean patients, overweight and obese subjects had increased circulating (P < 0.001) and hepatic (P = 0.003) CRP, and there was a significant correlation between serum protein and hepatic CRP mRNA levels (r(s)= 0.51, P < 0.001). Obesity (P = 0.001) and steatosis (P < 0.001) were associated with increased circulating but not hepatic IL-6, and a weak correlation was seen between serum protein and hepatic IL-6 mRNA levels (r(s)= 0.29, P = 0.003). An independent relationship was seen between hepatic TNF-alpha mRNA levels and higher total inflammatory score (P < 0.001) and stage of fibrosis (P = 0.037). Subjects with HCV genotype 3 had lower hepatic TNF-alpha mRNA levels compared with subjects with genotype 1 (P = 0.017), but there was no relationship between serum TNF-alpha protein and hepatic TNF-alpha mRNA levels. CONCLUSION: In patients with chronic HCV, obesity and steatosis are associated with increased expression of selected inflammatory markers; however, circulating levels of IL-6 and TNF-alpha do not reflect hepatic expression. Hepatic TNF-alpha was associated with both increased inflammatory activity and hepatic fibrosis, providing support for the key role of this pro-inflammatory cytokine in liver injury in chronic HCV.