Elevated fibrinogen and plasminogen activator inhibitor (PAI-1) in hypertension are related to metabolic risk factors for cardiovascular disease

Validation of a fibrinogen γ' enzyme-linked immunosorbent assay using a new monoclonal antibody: effects of bariatric surgery

Background

Fibrinogen γ' is a naturally occurring 20-amino-acid splice variant of the fibrinogen γ chain. Animal studies link variations in fibrinogen to obesity, but it is unknown how fibrinogen γ' is associated with obesity in humans.

Objectives

To develop and validate an enzyme-linked immunosorbent assay (ELISA) for fibrinogen γ' quantification in human plasma and analyze fibrinogen γ' before and after bariatric surgery.

Methods

We generated C-terminal fibrinogen γ' specific mouse monoclonal antibodies and developed a γ' ELISA. Validation included measures of accuracy, sensitivity, and precision. Fibrinogen γ' and total fibrinogen were measured in 60 individuals before and 6 months after bariatric surgery and in 19 normal-weight controls and 120 blood donors.

Results

Highly specific fibrinogen γ' monoclonal antibodies were produced and successfully used in the ELISA. Recovery was 88%, and limits of detection and quantification were 0.003 mg/mL and 0.014 mg/mL, respectively. Coefficients of variation were 3% for repeatability and 7% for within-laboratory variation. The fibrinogen γ' reference interval was 0.25 to 0.80 mg/mL. Fibrinogen γ' concentrations were reduced after bariatric surgery and were higher in individuals with obesity than in those with normal weight. The fibrinogen γ'/total fibrinogen ratio was unchanged after surgery but was higher than the ratio in normal-weight individuals.

Conclusion

We developed a precise and sensitive ELISA for fibrinogen γ'. Levels of fibrinogen γ', but not the fibrinogen γ'/fibrinogen ratio, were reduced 6 months after bariatric surgery. Absolute and relative levels of fibrinogen γ' were increased in individuals with obesity compared to normal-weight individuals.

Influence of Butyrate on Impaired Gene Expression in Colon from Patients with High Blood Pressure

Hypertension (HTN) is associated with gut dysbiosis and the depletion of butyrate-producing bacteria in animal models and people. Furthermore, fecal material transfer from donor hypertensive patients increases blood pressure in normotensive recipient animals and ameliorates HTN-associated pathophysiology. These observations have implications in the impaired interactions between the gut and gut microbiota in HTN. Although this concept is supported in animal models, little is known about human HTN. Therefore, our objective for this study was to compare gene expression with transcriptomics and its potential to influence microbiota in subjects with normal and high blood pressure (HBP). Colon samples from reference subjects with normal blood pressure (REF) and HBP were used for RNA-seq to analyze their transcriptomes. We observed the significant downregulation of gene sets governing immune responses (e.g., SGK1 and OASL), gut epithelial function (e.g., KRT20 and SLC9A3R1), gut microbiota (e.g., PPARG and CIDEC) and genes associated with cardiovascular and gut diseases (e.g., PLAUR and NLN) in HBP subjects; the expression of genes within these pathways correlated with blood pressure. Potential drug targets in the gut epithelium were identified using the Drug Gene International Database for possible use in HTN. They include peroxisome proliferator-activated receptor gamma (PPRG), active serum/glucocorticoid regulated kinase 1 (SGK1) and 3 beta-hydroxysteroid isomerase type II inhibitor (HSD3B). Finally, butyrate, a microbiota-derived short-chain fatty acid, restored the disrupted expression of certain functional genes in colonic organoids from HBP subjects. Patients with HBP exhibit a unique transcriptome that could underlie impaired gut-microbiota interactions. Targeting these interactions could provide a promising new therapeutic intervention for hypertension management.

Sex-specific associations between systolic, diastolic and pulse pressure and hemostatic parameters in the population-based KORA-Fit study: a cross-sectional study

BACKGROUND

Several prior studies postulated an effect of hypertension on coagulation factors. However, population-based studies investigating the sex-specific associations between hypertension and hemostatic parameters are scarce. Therefore, we investigated the relationship between blood pressure and parameters of coagulation, namely activated partial thromboplastin time (aPTT), international normalized ratio (INR), fibrinogen, factor VIII, antithrombin III, protein C, protein S, and D-dimer in men and women from the general population.

METHODS

Based on 803 participants (376 men, 427 women) from the KORA-Fit Study the sex-specific relationship between systolic, diastolic, and pulse pressure and commonly measured coagulation factors were investigated using multivariable-adjusted linear regression models.

RESULTS

Hypertensive males had significantly higher median fibrinogen levels and factor VIII activity in comparison to normotensive males. There was a statistically significant difference between females with and without hypertension regarding the parameter fibrinogen, D-dimers, Protein S activity, and factor VIII activity. In multivariable linear regression analyses no significant association between systolic blood pressure, diastolic blood pressure, as well as pulse pressure and the investigated hemostatic parameters was found in men. In women, a significant positive association could be observed between systolic blood pressure and D-dimer level [β-estimate per mmHg increase 3.37 (95% CI 0.935-5.804; p = 0.007)] and between pulse pressure and D-dimer level [β-estimate per mmHg increase 5.351 (95% CI 1.772-8.930; p = 0.003)].

CONCLUSIONS

It appears that sex differences exist in the association between blood pressure parameters and commonly measured coagulation markers in the general population. Further studies are needed to identify the underlying causes.

Fibrinogen, Fibrinogen-like 1 and Fibrinogen-like 2 Proteins, and Their Effects

Fibrinogen (Fg) and its derivatives play a considerable role in many diseases. For example, increased levels of Fg have been found in many inflammatory diseases, such as Alzheimer's disease, multiple sclerosis, traumatic brain injury, rheumatoid arthritis, systemic lupus erythematosus, and cancer. Although associations of Fg, Fg chains, and its derivatives with various diseases have been established, their specific effects and the mechanisms of actions involved are still unclear. The present review is the first attempt to discuss the role of Fg, Fg chains, its derivatives, and other members of Fg family proteins, such as Fg-like protein 1 and 2, in inflammatory diseases and their effects in immunomodulation.

Coagulation-Inspired Direct Fibrinogen Assay Using Plasmonic Nanoparticles Functionalized with Red Blood Cell Membranes

The fast measurement of fibrinogen is essential in evaluating life-threatening sepsis and cardiovascular diseases. Here, we aim to utilize biomimetic plasmonic Au nanoparticles using red blood cell membranes (RBCM-AuNPs) and demonstrate nanoscale coagulation-inspired fibrinogen detection via cross-linking between RBCM-AuNPs. The proposed biomimetic RBCM-AuNPs are highly suitable for fibrinogen detection because hemagglutination, occurring in the presence of fibrinogen, induces a shift in the localized surface plasmon resonance of the NPs. Specifically, when the two ends of the fibrinogen protein are bound to receptors on separate RBCM-AuNPs, cross-linking of the RBCM-AuNPs occurs, yielding a corresponding plasmon shift within 10 min. This coagulation-inspired fibrinogen detection method, with a low sample volume, high selectivity, and high speed, could facilitate the diagnosis of sepsis and cardiovascular diseases.

Effects of Angiotensin-Converting Enzyme Inhibition and Alpha 1-Adrenergic Receptor Blockade on Inflammation and Hemostasis in Human Hypertension

Drugs blocking the renin-angiotensin-aldosterone system may offer benefit on endothelial function, inflammation, and hemostasis in addition to the effects of reducing blood pressure. We examined the contribution of the angiotensin-converting enzyme inhibitor ramipril and the alpha 1-adrenergic receptor blocker doxazosin on blood pressure and on markers of inflammation and hemostasis in 59 individuals with mild-to-moderate hypertension randomized to receive double-blind ramipril 10 mg od or doxazosin 8 mg od for 12 weeks. Inflammatory markers (interleukin-6, soluble interleukin-6 receptor, interleukin-8, tumor necrosis factor-α, monocyte chemoattractant protein-1, and C-reactive protein) and hemostasis (plasminogen activator inhibitor-1 activity, tissue plasminogen activator antigen, thrombin-antithrombin complex, and thrombin generation by calibrated automated thrombogram) were assessed. The treatment reduced blood pressure in both groups. Thrombin-antithrombin complex decreased by treatment, and this was dependent on a reduction in thrombin-antithrombin complex in the ramipril group alone. There were no changes in plasminogen activator inhibitor-1 activity, whereas tissue plasminogen activator antigen increased by ramipril and decreased by doxazosin. Only minor changes were observed in systemic inflammation by treatment. Treatment with ramipril seems to reduce thrombin generation beyond effects on reducing blood pressure. Drugs blocking the renin-angiotensin-aldosterone system may reduce atherothrombotic complications beyond their effects to reduce blood pressure.

Pulmonary exposure to silver nanoparticles impairs cardiovascular homeostasis: Effects of coating, dose and time

Pulmonary exposure to silver nanoparticles (AgNPs) revealed the potential of nanoparticles to cause pulmonary toxicity, cross the alveolar-capillary barrier, and distribute to remote organs. However, the mechanism underlying the effects of AgNPs on the cardiovascular system remains unclear. Hence, we investigated the cardiovascular mechanisms of pulmonary exposure to AgNPs (10 nm) with varying coatings [polyvinylpyrrolidone (PVP) and citrate (CT)], concentrations (0.05, 0.5 and 5 mg/kg body weight), and time points (1 and 7 days) in BALB/C mice. Silver ions (Ag⁺) were used as ionic control. Exposure to AgNPs induced lung inflammation. In heart, tumor necrosis factor α, interleukin 6, total antioxidants, reduced glutathione and 8-isoprostane significantly increased for both AgNPs. Moreover, AgNPs caused oxidative DNA damage and apoptosis in the heart. The plasma concentration of fibrinogen, plasminogen activation inhibitor-1 and brain natriuretic peptide were significantly increased for both coating AgNPs. Likewise, the prothrombin time and activated partial thromboplastin time were significantly decreased. Additionally, the PVP- and CT- AgNPs induced a significant dose-dependent increase in thrombotic occlusion time in cerebral microvessels at both time points. In vitro study on mice whole blood exhibited significant platelet aggregation for both particle types. Compared with AgNPs, Ag⁺ increased thrombogenicity and markers of oxidative stress, but did not induce either DNA damage or apoptosis in the heart. In conclusion, pulmonary exposure to AgNPs caused cardiac oxidative stress, DNA damage and apoptosis, alteration of coagulation markers and thrombosis. Our findings provide a novel mechanistic insight into the cardiovascular pathophysiological effects of lung exposure to AgNPs.

Hyperfibrinogenemia-mediated astrocyte activation

Fibrinogen (Fg)-containing plaques are associated with memory loss during various inflammatory neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, stroke, and traumatic brain injury. However, mechanisms of its action in neurovascular unit are not clear. As Fg is a high molecular weight blood protein and cannot translocate far from the vessel after extravasation, we hypothesized that it may interact with astrocytes first causing their activation. Cultured mouse cortical astrocytes were treated with Fg in the presence or absence of function-blocking anti-mouse intercellular adhesion molecule 1 (ICAM-1) antibody, or with medium alone (control). Expressions of ICAM-1 and tyrosine receptor kinase B (TrkB) as markers of astrocyte activation, and phosphorylation of TrkB (pTrkB) were assessed. Fg dose-dependently increased activation of astrocytes defined by their shape change, retraction of processes, and enhanced expressions of ICAM-1 and TrkB, and increased pTrkB. Blocking of ICAM-1 function ameliorated these Fg effects. Data suggest that Fg interacts with astrocytes causing overexpression of ICAM-1 and TrkB, and TrkB phosphorylation, and thus, astrocyte activation. Since TrkB is known to be involved in neurodegeneration, interaction of Fg with astrocytes and the resultant activation of TrkB can be a possible mechanism involved in memory reduction, which were observed in previous studies and were associated with formation of complexes of Fg deposited in extravascular space with proteins such as Amyloid beta or prion, the proteins involved in development of dementia.

Plasminogen Activator Inhibitor-1 and Pericardial Fat in Individuals with Type 2 Diabetes Mellitus

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) is implicated in the pathophysiology of cardiovascular disease (CVD) and increased in individuals with type 2 diabetes mellitus (T2DM). Adipose tissue produces PAI-1, and pericardial fat is a CVD risk factor. We sought to determine the relationship between PAI-1 and pericardial fat in males and females with well-controlled T2DM.

METHODS

The study population consisted of 32 males and 19 females, aged 35-70 years with T2DM, without clinical evidence of CVD or other active medical problems except for hypertension. Subjects were studied under good cardiometabolic control. Study procedures included fasting blood work and cardiovascular imaging. Cardiac magnetic resonance imaging of the heart was used to identify and quantify pericardial fat from the bifurcation of the pulmonary trunk to the last slice containing cardiac tissue.

RESULTS

PAI-1 was positively correlated with pericardial fat (β = 0.72, r = 0.72, P < 0.001) as well as with homeostatic model assessment of insulin resistance (r = 0.31, P = 0.03) and serum triglycerides (r = 0.27, P = 0.05). In a multivariable regression model, controlling for insulin sensitivity, triglycerides, and body mass index, pericardial fat was independently associated with PAI-1 (β = 0.80, P < 0.001).

CONCLUSIONS

PAI-1 is positively associated with pericardial fat in individuals with T2DM.

Plasminogen Activator Inhibitor 1 Activity and Other Coronary Risk Factors

Because only some coronary risk factors have been evaluated for an association with plasma plasminogen activator inhibitor 1 (PAI-1) activity, this cross-sectional study examined the association between 27 coronary risk factors and PAI-1 in 24 healthy persons without coronary heart disease (control persons) and 22 patients who had survived myocardial infarction (cases). The coronary risk factors included major coronary risk factors such as age, anthropometric measures such as intraabdominal fat, and biochemical analytes such as serum concentration of triglyceride and plasma von Willebrand factor activity. The associations were analyzed in univariate and multiple linear regression analyses. For the control persons, triglyceride and von Willebrand factor were significantly associated with PAI-1 activity (p=0.0002, R2=0.55). In contrast for the 24 cases, age and intraabdominal adipose tissue were significantly associated with PAI-1 (p=0.0011, R2=0.51). Coronary risk factors explained more than half the variation of PAI-1 activity for both study groups. However, healthy persons and patients with previous myocardial infarction differed regarding coronary risk factors associated with PAI-1.

Leg Ulcer Patients: No Decreased Fibrinolytic Response but White Cell Trapping after Venous Occlusion of the Upper Limb

Objective:

To study changes in indicators of fibrinolytic activity and white cell trapping in response to raised venous pressure in the upper limbs of patients with chronic venous insufficiency.

Design:

Comparison of disease group versus control group study.

Setting:

Departments of Dermatology and Medicine, University of Freiburg.

Patient:

Thirty patients with chronic venous insufficiency and thirty control subjects of similar age with unrelated conditions.

Interventions:

The venous pressure was raised in one upper limb by application of a sphygmomanometer cuff around the upper arm for a period of 10 minutes.

Main outcome measures:

Red cell count, white cell count, plasminogen activator inhibitor, tissue plasminogen activator were measured in blood drawn from the arm subjected to raised venous pressure.

Results:

No significant changes were observed in the parameters of fibrinolytic activity. After 10 minutes of venous hypertension the white cell trapping in the disease group was 17.7% (interquartile range, 10.7–22), compared with 12.8% (interquartile range 4.9–16.1%) in the control group.

Conclusion:

The differences in white cell trapping parameters between healthy control subjects and patients with chronic venous insufficiency is probably attributable to systemic activation of white cells associated with their venous disease.

Cerebrovascular disorders caused by hyperfibrinogenaemia

KEY POINTS

Hyperfibrinogenaemia (HFg) results in vascular remodelling, and fibrinogen (Fg) and amyloid β (Aβ) complex formation is a hallmark of Alzheimer's disease. However, the interconnection of these effects, their mechanisms and implications in cerebrovascular diseases are not known. Using a mouse model of HFg, we showed that at an elevated blood level, Fg increases cerebrovascular permeability via mainly caveolar protein transcytosis. This enhances deposition of Fg in subendothelial matrix and interstitium making the immobilized Fg a readily accessible substrate for binding Aβ and cellular prion protein (PrP^C ), the protein that is thought to have a greater effect on memory than Aβ. We showed that enhanced formation of Fg-Aβ and Fg-PrP^C complexes are associated with reduction in short-term memory. The present study delineates a new mechanistic pathway for vasculo-neuronal dysfunctions found in inflammatory cardiovascular and cerebrovascular diseases associated with an elevated blood level of Fg.

ABSTRACT

Many cardiovascular diseases are associated with inflammation and as such are accompanied by an increased blood level of fibrinogen (Fg). Besides its well-known prothrombotic effects Fg seems to have other destructive roles in developing microvascular dysfunction that include changes in vascular reactivity and permeability. Increased permeability of brain microvessels has the most profound effects as it may lead to cerebrovascular remodelling and result in memory reduction. The goal of the present study was to define mechanisms of cerebrovascular permeability and associated reduction in memory induced by elevated blood content of Fg. Genetically modified, transgenic hyperfibrinogenic (HFg) mice were used to study cerebrovascular transcellular and paracellular permeability in vivo. The extent of caveolar formation and the role of caveolin-1 signalling were evaluated by immunohistochemistry (IHC) and Western blot (WB) analysis in brain samples from experimental animals. Formation of Fg complexes with amyloid β (Aβ) and with cellular prion protein (PrP^C ) were also assessed with IHC and WB analysis. Short-term memory of mice was assessed by novel object recognition and Y-maze tests. Caveolar protein transcytosis was found to have a prevailing role in overall increased cerebrovascular permeability in HFg mice. These results were associated with enhanced formation of caveolae. Increased formation of Fg-PrP^C and Fg-Aβ complexes were correlated with reduction in short-term memory in HFg mice. Using the model of hyperfibrinogenaemia, the present study shows a novel mechanistic pathway of inflammation-induced and Fg-mediated reduction in short-term memory.

Biocompatibility of cerium dioxide and silicon dioxide nanoparticles with endothelial cells

Cerium dioxide (CeO2) and silicon dioxide (SiO2) nanoparticles are of widespread use in modern life. This means that human beings are markedly exposed to them in their everyday life. Once passing biological barriers, these nanoparticles are expected to interact with endothelial cells, leading to systemic alterations with distinct influences on human health. In the present study we observed the metabolic impact of differently sized CeO2 (8 nm; 35 nm) and SiO2 nanoparticles (117 nm; 315 nm) on immortalized human microvascular (HMEC-1) and primary macrovascular endothelial cells (HUVEC), with particular focus on the CeO2 nanoparticles. The characterization of the CeO2 nanoparticles in cell culture media with varying serum content indicated a steric stabilization of nanoparticles due to interaction with proteins. After cellular uptake, the CeO2 nanoparticles were localized around the nucleus in a ring-shaped manner. The nanoparticles revealed concentration and time, but no size-dependent effects on the cellular adenosine triphosphate levels. HUVEC reacted more sensitively to CeO2 nanoparticle exposure than HMEC-1. This effect was also observed in relation to cytokine release after nanoparticle treatment. The CeO2 nanoparticles exhibited a specific impact on the release of diverse proteins. Namely, a slight trend towards pro-inflammatory effects, a slight pro-thrombotic impact, and an increase of reactive oxygen species after nanoparticle exposure were observed with increasing incubation time. For SiO2 nanoparticles, concentration- and time-dependent effects on the metabolic activity as well as pro-inflammatory reactions were detectable. In general, the effects of the investigated nanoparticles on endothelial cells were rather insignificant, since the alterations on the metabolic cell activity became visible at a nanoparticle concentration that is by far higher than those expected to occur in the in vivo situation (CeO2 nanoparticles: 100 µg/mL; SiO2 nanoparticles: 10 µg/mL).

Metabolic syndrome: is equine disease comparable to what we know in humans?

This review summarizes similarities and differences between the metabolic syndromes in humans and equines, concerning the anatomy, symptoms, and pathophysiological mechanisms. In particular, it discusses the structure and distribution of adipose tissue and its specific metabolic pathways. Furthermore, this article provides insights and focuses on issues concerning laminitis in horses and cardiovascular diseases in humans, as well as their overlap.

Metabolic syndrome and insulin resistance: underlying causes and modification by exercise training

Metabolic syndrome (MS) is a collection of cardiometabolic risk factors that includes obesity, insulin resistance, hypertension, and dyslipidemia. Although there has been significant debate regarding the criteria and concept of the syndrome, this clustering of risk factors is unequivocally linked to an increased risk of developing type 2 diabetes and cardiovascular disease. Regardless of the true definition, based on current population estimates, nearly 100 million have MS. It is often characterized by insulin resistance, which some have suggested is a major underpinning link between physical inactivity and MS. The purpose of this review is to: (i) provide an overview of the history, causes and clinical aspects of MS, (ii) review the molecular mechanisms of insulin action and the causes of insulin resistance, and (iii) discuss the epidemiological and intervention data on the effects of exercise on MS and insulin sensitivity.

Elevated plasminogen activator inhibitor type-1 (PAI-1) as contributing factor in pathogenesis of hypercoagulable state in antiphospholipid syndrome

The aim of this study is to explore the role of plasminogen activator inhibitor type 1 (PAI-1) in primary and secondary antiphospholipid syndrome (APS). Thirty patients of APS (24 primary and 6 secondary) were recruited in the study who fulfilled the revised Sapporo criteria. Control groups comprised of age- and sex-matched 10 healthy volunteers and 10 patients each of systemic lupus erythematosus and rheumatoid arthritis without any antecedent thrombotic event and/or APS-related pregnancy morbidity. Serum samples were tested for PAI-1 antigen levels measured by quantitative ELISA. Positivity rate of PAI-1 in patients of primary, secondary as well as total APS patients was significantly higher in relation to age- and sex-matched healthy volunteers (p = 0.010, p = 0.003 and p < 0.001, respectively). Mean ± SEM levels of PAI-1 in primary and secondary as well as total APS patients were significantly higher (p = 0.006, p < 0.001 and p < 0.001) in relation to healthy controls. Correlation of PAI-1 levels (mean ± SEM) with clinical characteristics, that is, thrombosis and pregnancy morbidity, revealed significantly higher levels of PAI-1 (p < 0.001) in patients having thrombosis and APS-related pregnancy morbidity. Elevated PAI-1 level leading to impaired fibrinolysis plays a significant role in producing hypercoagulable state in primary and secondary APS.

Association between the rs6950982 polymorphism near the SERPINE1 gene and blood pressure and lipid parameters in a high-cardiovascular-risk population: interaction with Mediterranean diet

The SERPINE1 (serpin peptidase inhibitor, clade E, member 1) gene, better known by its previous symbol PAI-1 (plasminogen activator inhibitor 1), has been associated with cardiovascular phenotypes with differing results. Our aim was to examine the association between the rs6950982 (G > A) near the SERPINE1 gene, blood pressure (BP) and plasma lipid concentrations as well as the modulation of the polymorphism effects by adherence to Mediterranean diet (AMD). We studied 945 high-cardiovascular-risk subjects. Biochemical, clinical, dietary and genetic data (rs6950982) were obtained. We also determined the common rs1799768 (4G/5G), for checking independent effects. AMD was measured by a validated questionnaire, and four groups were considered. rs6950982 (A > G) and rs1799768 (4G/5G) were only in moderate-low linkage disequilibrium (D' = 0.719; r (2) = 0.167). The most significant associations we obtained were with rs6950982 (A > G). In males, the G allele was nominally associated with higher diastolic BP (AA: 81.5 ± 10.9, AG: 82.1 ± 11.4, GG: 85.7 ± 10.5 mmHg; P additive = 0.030) and systolic BP (AA + AG: 141.4 ± 6.9 mmHg vs. GG: 149.8 ± 8.0 mmHg; P recessive = 0.036). In the whole population, the rs6950982 was also associated with plasma lipids. Subject with the G allele presented higher total cholesterol (P additive = 0.016, P recessive = 0.011), low-density lipoprotein cholesterol (P additive = 0.032, P recessive = 0.031) and triglycerides (P additive = 0.040, P recessive = 0.029). AMD modulated the effect of rs6950982 on triglyceride concentrations (P for interaction = 0.036). Greater AMD reduced the higher triglyceride concentrations in GG subjects. No significant interactions were found for the other parameters. The rs6950982 was associated with higher BP in men and higher triglycerides in the whole population, this association being modulated by AMD.

Knockout of SOD1 alters murine hepatic glycolysis, gluconeogenesis, and lipogenesis

We previously observed a stronger effect of knockout of Cu,Zn-superoxide dismutase (SOD1) than that of Se-dependent glutathione peroxidase 1 (GPX1) on murine body weight and glucose homeostasis. Two experiments were conducted to determine how hepatic lipid profiles and key metabolic regulators were correlated with this difference. SOD1(-/-) and GPX1(-/-) mice and their respective wild-type (WT) littermates (n=6 or 7/group, male) were fed a Se-adequate Torula yeast-sucrose diet and killed at 6 months of age to collect liver samples. In Experiment 1, fasted SOD1(-/-) mice displayed pyruvate intolerance and a 61% decrease (P<0.05) in liver glycogen compared with their WT littermates. The former had lower (P<0.05) activities of phosphoenolpyruvate carboxykinase, total protein phosphatase, and protein phosphatase 2A, but a higher (P<0.05) activity of glucokinase in the liver than the latter. In contrast, hepatic concentrations of total cholesterol, triglycerides, and nonesterified fatty acids were increased by 11 to 100% (P<0.05) in the SOD1(-/-) mice. Meanwhile, these mice had elevated (P<0.05) hepatic protein levels of sterol-regulatory element binding proteins 1 and 2, p53 MAPK, total and phosphorylated AMP-activated protein kinase α1 protein, protein tyrosine phosphatase 1B, and protein phosphatase 2B. In Experiment 2, GPX1(-/-) mice and their WT littermates were compared, but showed no difference in any of the measures. In conclusion, knockout of SOD1, but not GPX1, led to a decreased liver glycogen storage synchronized with pyruvate intolerance and elevated hepatic lipid profiles in adult mice. This striking comparison was possibly due to unique impacts of these two knockouts on intracellular tone of H(2)O(2) and key regulators of liver gluconeogenesis, glycolysis, and lipogenesis.

Fibrinogen-induced increased pial venular permeability in mice

Elevated blood level of Fibrinogen (Fg) is commonly associated with vascular dysfunction. We tested the hypothesis that at pathologically high levels, Fg increases cerebrovascular permeability by activating matrix metalloproteinases (MMPs). Fibrinogen (4 mg/mL blood concentration) or equal volume of phosphate-buffered saline (PBS) was infused into male wild-type (WT; C57BL/6J) or MMP-9 gene knockout (MMP9-/-) mice. Pial venular leakage of fluorescein isothiocyanate-bovine serum albumin to Fg or PBS alone and to topically applied histamine (10(-5) mol/L) were assessed. Intravital fluorescence microscopy and image analysis were used to assess cerebrovascular protein leakage. Pial venular macromolecular leakage increased more after Fg infusion than after infusion of PBS in both (WT and MMP9-/-) mice but was more pronounced in WT compared with MMP9-/- mice. Expression of vascular endothelial cadherin (VE-cadherin) was less and plasmalemmal vesicle-associated protein-1 (PV-1) was greater in Fg-infused than in PBS-infused both mice groups. However, in MMP9-/- mice, VE-cadherin expression was greater and PV-1 expression was less than in WT mice. These data indicate that at higher levels, Fg compromises microvascular integrity through activation of MMP-9 and downregulation of VE-cadherin and upregulation of PV-1. Our results suggest that elevated blood level of Fg could have a significant role in cerebrovascular dysfunction and remodeling.

Insulin resistance explains the relationship between novel cardiovascular risk factors and hypertension. The Telde Study

BACKGROUND

Most studies describing an association between hypertension and an inflammatory/pro-thrombotic state do not assess insulin resistance.

AIM

To examine the association between hypertension and new cardiovascular risk factors when considering both classical risk factors and insulin resistance.

METHODS

In a population-based sample of 1030 subjects, clinical information and blood samples were obtained. Subjects were classified according to the presence or absence of hypertension, and insulin resistance was estimated using the homeostasis model of assessment (HOMA). To identify variables independently associated with hypertension, a four-model multiple logistic regression was performed: model 1 included novel risk factors (Plasminogen Activator Inhibitor- 1 [PAI-1], fibrinogen, von Willebrand Factor [vWF], lipoprotein(a), homocysteine and C-reactive Protein [CRP]); model 2, novel risk factors plus HOMA; model 3 included both classical (smoking, triglycerides, HDL cholesterol, total cholesterol, waist circumference and diabetes) and novel risk factors and model 4, model 3 plus HOMA. All were adjusted for age, BMI and gender and compared using Akaike's Information Criterion (AIC).

RESULTS

In model 1, only PAI-1, age and BMI showed association with hypertension.When HOMA and classical risk factors were also included, PAI-1 was replaced by triglyceride, smoking and diabetes. The lowest AIC value (best adjustment) was displayed by model 4, comprising all of the variables. Only age, BMI, HOMA and smoking remained significantly associated with hypertension.

CONCLUSIONS

The novel cardiovascular risk factors assessed do not add information as markers of hypertension when classical risk factors or insulin resistance are included in the evaluation.

Effects of lisinopril, irbesartan, and amlodipine on the thrombogenic variables in the early and late stages of the treatment in hypertensive patients

Regulation of the fibrinolytic balance between plasminogen activators and inhibitors is modulated by the renin-angiotensin system (RAS). Impaired fibrinolytic function, characterized by increased plasminogen activator inhibitor type 1 (PAI-1) levels and decreased tissue plasminogen activator (t-PA) activity, has been found in patients with hypertension and may account in part for the increased risk of atherosclerosis and its clinical complications in these patients. In this regard, data from the literature indicate that different antihypertensive drugs may vary in their influence on fibrinolysis. Angiotensin-converting enzyme (ACE) inhibitors (ACE-I) have generally been shown to improve the fibrinolytic balance by reducing plasma PAI-1 levels. Calcium-channel blockers (CCB) have been reported to increase t-PA activity, and angiotensin receptor blockers (ARB) seem to be neutral in their effect. In the light of these data, this study aimed to compare the effects of ACE-I, ARB, and CCB on the fibrinolytic system in the early and late stages of the treatment in hypertensive patients. These data that the beneficial effect of RAS inhibition on fibrinolysis related to decrease in Ang II during early period of treatment. Amlodipine may also improve thrombogenic risk related to lowering the effect on increased platelet activation reflected by p-selectin. The greater improvement in the early and late stages of the fibrinolytic balance because of the combined action of RAS inhibition and Ca antagonism represents a further indication to the use of combinations of RAS inhibition (ACE-I or ARB) and CCB in the treatment of hypertension.

Plasma plasminogen activator inhibitor 1 (PAI-1) and P-selectin levels in urgent hypertension: effect of single dose captopril and nifedipine on fibrinolytic activity

In this study, we primarily aimed to identify the acute effects of hypertension on fibrinolytic function in previously untreated urgent hypertensive patients and to evaluate the influence of two commonly used, short-acting, anti-hypertensive agents, captopril and nifedipine, in these patients. Patient groups were selected homogeneously, i.e., only previously untreated patients amidst an urgent hypertensive episode and having no co-morbid disease were included-and randomly assigned to receive either captopril or nifedipine for immediate management. These two treatment groups were matched for age, gender, and mean arterial blood pressure. Study results demonstrated that lowering blood pressure with either agent improved fibrinolytic function; however, in those patients given captopril, this beneficial effect was more prominent, providing evidence supporting the preferential use of short-acting, angiotensin-converting enzyme (ACE) inhibitors in this setting.

Efficacy of olmesartan therapy on fibrinolytic capacity in patients with hypertension

The efficacy of olmesartan on fibrinolytic capacity has not been studied yet. Therefore, the aim of the present study was to investigate the efficacy of olmesartan on hemostatic/fibrinolytic status by measuring plasma level of plasminogen activator inhibitor-1 (PAI-1) and soluble thrombomodulin levels in patients with hypertension. Forty-two consecutive, newly diagnosed (25 women and 17 men with a mean age of 48 ± 8 years) patients with untreated essential hypertension were included in the study. Olmesartan medoxomil (20 mg/day) was started and the patients were followed up for 6 months. Baseline biochemical variables, thrombomodulin, and PAI-1 levels were compared with the levels of these variables measured at the end of the 6-month follow-up period. After 6 months of treatment with olmesartan medoxomil, there was a significant reduction in systolic and diastolic blood pressure (from 159.5 ± 10.9 to 134.6 ± 12.7 mmHg and from 98.0 ± 6.3 to 83.9 ± 7.0 mmHg, respectively). Mean plasma PAI-1 and thrombomodulin levels were also significantly decreased (59.73 ± 41.91 vs. 48.60 ± 33.65 ng/ml, P = 0.001 and 8.09 ± 2.29 vs. 6.92 ± 1.42 μg/l, P < 0.001, respectively). Olmesartan medoxomil decreased plasma PAI-1 and thrombomodulin levels after 6 months of therapy, indicating a favorable effect on fibrinolytic capacity in patients with essential hypertension.

Ezetimibe therapy and its influence on oxidative stress and fibrinolytic activity

OBJECTIVE

The effect of ezetimibe on blood lipids, oxidative stress, and fibrinolytic activity in hyperlipidemic patients was investigated after three months of therapy.

METHODS

Thirty hyperlipidemic patients were treated for twelve weeks with ezetimibe 10 mg/day. A healthy control group with matching age and gender was also included. Fasting blood glucose, lipid parameters, paraoxonase (PON1), protein carbonyl (PCO), oxidized LDL (oxLDL), 8-isoprostane (ISOPR), total antioxidant capacity (TAC) levels, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type-1 (PAI-1), and PAI-1/t-PA levels were evaluated.

RESULTS

Ezetimibe therapy for twelve weeks led to changes in lipid profile in accordance with the literature. Fibrinolytic activity parameters, PAI-1/tPA and tPA-1 decreased, whereas PAI-1 levels did not change significantly. Antioxidant parameters, serum PON1 activity, and TAC levels increased significantly compared with the basal values. Oxidant parameters, oxLDL, ISOPR, and PCO (which is an indicator of oxidative protein damage) decreased significantly after therapy.

CONCLUSIONS

Ezetimibe therapy has beneficial effects on fibrinolytic activity and homeostasis between oxidant and antioxidant activity in hyperlipidemic patients This may be through lowering lipid levels or other mechanisms such as decreasing insulin resistance and the pleiotropic effects of the drug.

Mechanisms of fibrinogen-induced microvascular dysfunction during cardiovascular disease

Fibrinogen (Fg) is a high molecular weight plasma adhesion protein and a biomarker of inflammation. Many cardiovascular and cerebrovascular disorders are accompanied by increased blood content of Fg. Increased levels of Fg result in changes in blood rheological properties such as increases in plasma viscosity, erythrocyte aggregation, platelet thrombogenesis, alterations in vascular reactivity and compromises in endothelial layer integrity. These alterations exacerbate the complications in peripheral blood circulation during cardiovascular diseases such as hypertension, diabetes and stroke. In addition to affecting blood viscosity by altering plasma viscosity and erythrocyte aggregation, growing experimental evidence suggests that Fg alters vascular reactivity and impairs endothelial cell layer integrity by binding to its endothelial cell membrane receptors and activating signalling mechanisms. The purpose of this review is to discuss experimental data, which demonstrate the effects of Fg causing vascular dysfunction and to offer possible mechanisms for these effects, which could exacerbate microcirculatory complications during cardiovascular diseases accompanied by increased Fg content.

Fibrinogen-induced endothelin-1 production from endothelial cells

We previously demonstrated that fibrinogen (Fg) binding to the vascular endothelial intercellular adhesion molecule-1 (ICAM-1) leads to microvascular constriction in vivo and in vitro. Although a role of endothelin-1 (ET-1) in this Fg-induced vasoconstriction was suggested, the mechanism of action was not clear. In the current study, we tested the hypothesis that Fg-induced vasoconstriction results from ET-1 production by vascular endothelial cells (EC) and is mediated by activation of extracellular signal-regulated kinase -1/2 (ERK-1/2). Confluent, rat heart microvascular endothelial cells (RHMECs) were treated with one of the following: Fg (2 or 4 mg/ml), Fg (4 mg/ml) with ERK-1/2 kinase inhibitors (PD-98059 or U-0126), Fg (4 mg/ml) with an antibody against ICAM-1, or medium alone for 45 min. The amount of ET-1 formed and the concentration of released von Willebrand factor (vWF) in the cell culture medium were measured by ELISAs. Fg-induced exocytosis of Weibel-Palade bodies (WPBs) was assessed by immunocytochemistry. Phosphorylation of ERK-1/2 was detected by Western blot analysis. Fg caused a dose-dependent increase in ET-1 formation and release of vWF from the RHMECs. This Fg-induced increase in ET-1 production was inhibited by specific ERK-1/2 kinase inhibitors and by anti-ICAM-1 antibody. Immunocytochemical staining showed that an increase in Fg concentration enhanced exocytosis of WPBs in ECs. A specific endothelin type B receptor blocker, BQ-788, attenuated the enhanced phosphorylation of ERK-1/2 in ECs caused by increased Fg content in the culture medium. The presence of an endothelin converting enzyme inhibitor, SM-19712, slightly decreased Fg-induced phosphorylation of ERK-1/2, but inhibited production of Fg-induced ET-1 production. These results suggest that Fg-induced vasoconstriction may be mediated, in part, by activation of ERK-1/2 signaling and increased production of ET-1 that further increases EC ERK-1/2 signaling. Thus, an increased content of Fg may enhance vasoconstriction through increased production of ET-1.

Relationships of systemic oxidative stress to body fat distribution, adipokines and inflammatory markers in healthy middle-aged women

Obesity and systemic oxidative stress are closely related. However data concerning the relationships between oxidative stress and body fat mass distribution are sparse. Anthropometric and metabolic profile was evaluated in 148 clinically healthy middle-aged women to assess the correlations between oxidative stress, fat mass distribution, adipokines, and inflammatory markers. Systemic oxidative stress was assessed by urinary creatinine-indexed 8-epi-prostaglandin F-(2alpha) (8-epi-PGF(2alpha)). Body fat mass distribution was examined by dual-energy X-ray absorptiometry (DXA). Lipid profile, adipokines and inflammatory markers including leptin, adiponectin, high sensitive C-reactive protein (hsCRP), plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-alpha (TNF-alpha) were determined. We found body mass index (BMI), waist circumference (WC), both central and peripheral DXA-derived regional fat mass (FM) accumulations were positively correlated with 8-epi-PGF(2alpha). Leptin, hsCRP and PAI-1also positively associated with 8-epi-PGF(2alpha). After adjustment for BMI and WC, lower-body FM, total FM and PAI-1 retained significant association with 8-epi-PGF(2alpha). Mutliple linear regression analyses indicated lower-body FM and PAI-1 were the two important predicators of 8-epi-PGF(2alpha). These results suggest that DXA-derived regional FM indices, especially low extremity adiposity, are more closely associated with systemic oxidative stress than indirect anthropometric indices. Positive associations between 8-epi-PGF(2alpha) and PAI-1, hsCRP, leptin support the notion that oxidative-stress-induced dysregulation of inflammation and adipokines may mediate the obesity-related metabolic derangement.

Endothelial dysfunction in diabetes mellitus

Diabetes mellitus is associated with an increased risk of cardiovascular disease, even in the presence of intensive glycemic control. Substantial clinical and experimental evidence suggest that both diabetes and insulin resistance cause a combination of endothelial dysfunctions, which may diminish the anti-atherogenic role of the vascular endothelium. Both insulin resistance and endothelial dysfunction appear to precede the development of overt hyperglycemia in patients with type 2 diabetes. Therefore, in patients with diabetes or insulin resistance, endothelial dysfunction may be a critical early target for preventing atherosclerosis and cardiovascular disease. Microalbuminuria is now considered to be an atherosclerotic risk factor and predicts future cardiovascular disease risk in diabetic patients, in elderly patients, as well as in the general population. It has been implicated as an independent risk factor for cardiovascular disease and premature cardiovascular mortality for patients with type 1 and type 2 diabetes mellitus, as well as for patients with essential hypertension. A complete biochemical understanding of the mechanisms by which hyperglycemia causes vascular functional and structural changes associated with the diabetic milieu still eludes us. In recent years, the numerous biochemical and metabolic pathways postulated to have a causal role in the pathogenesis of diabetic vascular disease have been distilled into several unifying hypotheses. The role of chronic hyperglycemia in the development of diabetic microvascular complications and in neuropathy has been clearly established. However, the biochemical or cellular links between elevated blood glucose levels, and the vascular lesions remain incompletely understood. A number of trials have demonstrated that statins therapy as well as angiotensin converting enzyme inhibitors is associated with improvements in endothelial function in diabetes. Although antioxidants provide short-term improvement of endothelial function in humans, all studies of the effectiveness of preventive antioxidant therapy have been disappointing. Control of hyperglycemia thus remains the best way to improve endothelial function and to prevent atherosclerosis and other cardiovascular complications of diabetes. In the present review we provide the up to date details on this subject.

Effect of delapril/manidipine vs olmesartan/ hydrochlorothiazide combination on insulin sensitivity and fibrinogen in obese hypertensive patients

OBJECTIVE

To compare the effect of delapril/manidipine vs olmesartan/hydrochlorothiazide (HCTZ) combination on insulin sensitivity and plasma fibrinogen in obese hypertensive patients.

PATIENTS AND METHODS

After a 4-week placebo period, 88 obese, hypertensive (DBP >95 and <110 mmHg) outpatients were randomized to delapril 30 mg/manidipine 10 mg combination or to olmesartan 20 mg/HCTZ 12.5 mg combination for 24 weeks according to a prospective, randomized, open-label, blinded endpoint, parallel group design. At the end of the placebo period and treatment period, clinical BP, fasting plasma glucose (FPG), plasma insulin, insulin sensitivity (by euglycemic hyperinsulinemic clamp) and plasma fibrinogen were evaluated. Insulin sensitivity was expressed as the amount of glucose infused during the last 30 minutes (glucose infusion rate, GIR) in mg/Kg/min. The total glucose requirement (TGR) to maintain a steady-state blood glucose level in response to a defined increase in plasma insulin concentration was also evaluated.

RESULTS

Both combinations significantly reduced SBP/DBP values (-22.3/16.4 mmHg and -22.6/17.2 mmHg, respectively, all p <0.001 vs placebo). GIR was significantly increased only by delapril/manidipine (+3.01 mg/min/Kg, p=0.038 vs placebo), the difference between treatments being significant (p <0.05). TGR was significantly increased by delapril/manidipine (+9.7 g, p=0.034), while it was unaffected by olmesartan/HCTZ. Plasma insulin as well as fibrinogen were significantly reduced by delapril/manidipine (-17.8 pmol/l, p=0.047 and -67.5 mg/dl, p=0.021, respectively), but not by olmesartan/HCTZ, the difference between the two treatments being statistically significant (p <0.05).

CONCLUSION

In obese hypertensive patients the delapril/manidipine combination but not the olmesartan/HCTZ combination significantly decreased insulin resistance and plasma fibrinogen levels, despite the similar BP lowering efficacy.

The effects of nebivolol on fibrinolytic parameters in mild and moderate hypertensive patients

BACKGROUND

The aim of the present study was to investigate the effects of nebivolol (5 mg daily) on plasma levels of hemostatic and fibrinolytic endothelial function markers in mild or moderate hypertensive patients.

METHODS AND RESULTS

Thirty-five (22 female, 13 male; mean +/- SD 54.7 +/- 11.3 years of age) mild and moderate hypertensive patients were included the study. The mean systolic blood pressure [BP] was 160 mmHg (range 150 mmHg to 165 mmHg) and the mean diastolic BP was 100 mmHg (range 90 mmHg to 100 mmHg). Plasma tissue plasminogen activator antigen (tPA-Ag), plasminogen activator inhibitor type 1 antigen (PAI-1-Ag), PAI-1 activity, tPA-Ag/PAI-1-Ag index, fibrinogen and euglobulin lysis time were determined before and after two months of therapy. tPA-Ag and PAI-Ag levels were measured by ELISA. After this period, treatment with nebivolol (5 mg/day) in all patients was associated with a significant decrease in systolic BP and diastolic BP (P<0.001 for each), heart rate (P<0.01), fibrinogen (P<0.005) and euglobulin lysis time (P<0.01). The tPA-Ag and tPA-Ag/PAI-1-Ag index levels were increased significantly (P<0.001 for each) in all patients, but the PAI-1-Ag (P>0.05) and PAI-1 activity (P>0.05) did not show significant change. In the present study, there was no correlation between decreases in arterial BP and decreases in fibrinolytic parameters (P>0.05), but there was a positive, statistically significant correlation between fibrinogen and body mass index (P<0.001).

CONCLUSIONS

The results indicated that, compared with no treatment, a two-month treatment trial with nebivolol was associated with a more favourable modification of hemostatic and fibrinolytic status in addition to antihypertensive effects.

Diabetes mellitus as a prothrombotic condition

Diabetes mellitus (DM) is characterized by fasting hyperglycaemia and a high risk of atherothrombotic disorders affecting the coronary, cerebral and peripheral arterial trees. The risk of myocardial infarction (MI) is 3-5 fold higher in Type 2 DM and a DM subject with no history of MI has the same risk as a non-DM subject with a past history of MI. In total around 70% of deaths are vascular with poorer outcomes to both acute events and cardiological interventions. It was proposed that clustering of vascular risk factors (hyperinsulinaemia, dysglycaemia, dyslipidaemia and hypertension) around insulin resistance (IR) accounted for the increase in risk with Type 2 DM. The importance of this became apparent with the recognition that risk clustering occurs in normoglycaemic and impaired glucose tolerance (IGT) subjects with IR, in total around 25% of the population in addition to long-standing Type 1 subjects with renal disease. Evidence indicates that thrombotic risk clustering also occurs in association with IR, suppression of fibrinolysis due to elevated concentrations of the fibrinolytic inhibitor, plasminogen activator inhibitor-1 (PAI-1) is invariable with IR and there is evidence that this is regulated by the effects of triglyceride on the PAI-1 gene promoter. Other studies indicated that prothrombotic risk (coagulation factors VII, XII and fibrinogen) also associates with the IR syndrome. The development of endothelial cell dysfunction with suppression of nitric oxide and prostacyclin synthesis, combined with platelet resistance to the anti-aggregatory effects of these hormones leads to loss of control over platelet activation. In addition, hyperglycaemia and glycation have marked effects on fibrin structure function, generating a clot which has a denser structure, resistant to fibrinolysis. The combination of increased circulating coagulation zymogens, inhibition of fibrinolysis, changes in fibrin structure/function and alterations in platelet reactivity creates a thrombotic risk clustering which underpins the development of cardiovascular disease.

Fibrinolytic system in normotensive subjects and hypertensive patients

The aim of this study was to evaluate the fibrinolytic system by measurement of fibrinogen, plasminogen, tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) in healthy normotensive subjects and in patients with essential hypertension. A group of 21 healthy normotensive subjects [age, 39.2 +/- 1.8 years; 8 males, 13 females; body mass index (BMI) = 27.9 kg/m] and 42 patients with untreated essential hypertension (age, 47.6 +/- 1.7 years; 19 males, 23 females; BMI = 28.3 kg/m) were studied. Blood samples and clinical measurement were taken between 7 am and 9 am by an observer in a blind fashion. The systolic/diastolic blood pressure of normotensive subjects was 121.3 +/- 2.5/78.4 +/- 1.3 mm Hg and that of hypertensive patients was 166.4 +/- 4.3/102.9 +/- 1.83 mm Hg, measured in the sitting position. Plasma fibrinogen levels in the normotensive and hypertensive individuals were 295.7 +/- 9.4 mg/dL and 305.67 +/- 10.9 mg/dL, respectively (P = 0.456). The corresponding values for plasminogen were 71.4 +/- 3.8% and 89.5 +/- 2.5%, (P = 0.0031), for t-PA were 6.3 +/- 0.5 ng/mL and 7.6 +/- 0.4 ng/mL (P = 0.0487), and for PAI-1 were 46.9 +/- 5.1 ng/mL and 63.0 +/- 5.6 ng/mL (P = 0.0324), respectively. In conclusion, patients with essential hypertension have disequilibrium in the fibrinolytic system with a tendency toward a hypercoagulability state when compared with normotensive subjects. This state could explain, in part, the thrombotic complications that occur with a higher frequency in hypertensive patients as compared with normotensive subjects.

Plasma levels of fibrinogen and C-reactive protein are related to interleukin-6 gene −572C>G polymorphism in subjects with and without hypertension

Hypertension is an important risk factor for cardiovascular diseases. There is increasing evidence suggesting that inflammation is involved in the development of hypertension. Interleukin-6 (IL-6) is an important mediator of inflammatory response and the major regulator of hepatic production of acute phase proteins, such as fibrinogen and C-reactive protein (CRP), which have been associated with hypertension and cardiovascular diseases. Therefore, we studied the association of single nucleotide polymorphism (SNP) in the IL-6 gene (IL6) promoter with plasma levels of fibrinogen, CRP and hypertension. Five hundred and two Hong Kong Chinese subjects (282 normotensives and 220 hypertensives) were recruited. IL-6 gene promoter was examined for polymorphism and the study subjects were genotyped for any SNP identified. The IL6 -572C>G polymorphism (rs1800796) was found with a frequency of 0.23 for the minor G allele. Subjects with the -572G allele had significantly higher plasma fibrinogen (3.06+/-0.57 vs 2.83+/-0.60, P=0.002) and CRP (interquartile range 0.33-1.56 vs 0.12-0.93, P=0.003) levels than those without. The -572C>G polymorphism was found to be an independent predictor of fibrinogen and CRP levels after adjusting for confounding factors. Plasma concentrations of fibrinogen and CRP correlated with systolic blood pressure. However, the -572C/G genotype frequencies did not differ between hypertensive and normotensive subjects, and there was no association between -572C>G polymorphism and blood pressure. Our results provide evidence that there is a clear genetic influence of IL6 -572C>G polymorphism on plasma levels of fibrinogen and CRP, but this polymorphism does not lead to elevated blood pressure.

The effect of high plasma levels of angiotensin-converting enzyme (ACE) and plasminogen activator inhibitor (PAI-1) on the reperfusion after thrombolytic therapy in patients presented with acute myocardial infarction

The resistance to thrombolytic agents and delays in reperfusion occur in more than 30% after acute myocardial infarction. This may play an important role in the unsuccessful recanalization after thrombolytic therapy. The aim of this study is to assess the clinical and biochemical markers of reperfusion after different types of thrombolytic therapy and to find out the relationship between PAI-1 and ACE serum levels and the short-term outcome. Pretreatment ACE and PAI-1 plasma levels of 184 patients with acute myocardial infarction, treated with thrombolytic therapy were determined. Failure of thrombolysis was considered when reperfusion was delayed as assessed by noninvasive reperfusion criteria, reinfarction, and impaired left ventricular function. High plasma level of ACE (> 50 U/L), PAI-1 (> 43 ng/ml) and both was found in 57, 108 and 32 patients respectively. Subjects with high ACE plasma levels were characterized by impaired LV systolic function (79.0% vs. 75.0%), new Q-wave (88.4% vs. 74.2%), less reperfusion arrhythmia (19.3% vs. 22.8%) and prolonged hospitalization (70% vs. 66%) but no statistical significance was observed. High enzymes levels of PAI-1 were observed with higher incidence of anterior myocardial infarction (50.0% vs. 41.0%), lesser ST segment resolution (65.6% vs. 58.8%), reinfarction (6.3% vs. 5.9%), and impaired LV systolic function (90.6% vs. 76.0%), and prolonged hospitalization (70.4% vs. 63.4). There was a statistically significant difference between thrombolytic agents in the presence of high ACE regarding hospital overstay (p = 0.02). While the presence of high PAI-1 was significantly affect the degree of ST-segment resolution (p = 0.03).

CONCLUSION

High plasma ACE and/or PAI-1 plays a considerable role in the higher incidence of unsuccessful reperfusion and impaired left ventricular function after thrombolytic therapy. A rapid diagnostic tool that enables physician of detecting those enzymes before giving thrombolytic therapy may change the strategy of treatment to offer another effective revascularization method.

Human gender differences in fibrinolytic responses to exercise training and their determinants

Endurance exercise training improves fibrinolysis, but this training-induced adaptation may differ somewhat between men and women. We sought to determine whether the potential gender differences in training-induced changes in selected fibrinolysis measures were related to changes in adiposity and/or plasma lipoprotein lipid levels. Seventeen men and 28 women, 50-75 years old, who were generally overweight to obese, were assessed for plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (t-PA) activity, t-PA antigen and plasma lipoprotein-lipid levels, and body composition before and after 6 months of endurance exercise training while on a low-fat diet. At baseline, there were no differences in fibrinolytic measures between the men and women. Baseline levels of these fibrinolytic markers in both men and women were primarily related to other fibrinolytic measures and body composition, with a smaller contribution from plasma high-density lipoprotein cholesterol (HDL-C) levels. Exercise training reduced t-PA antigen levels in both men and women, but the reduction was significantly greater in men (-1.6 +/- 0.3 versus -0.5 +/- 0.2 ng ml(-1), P = 0.007). Exercise training decreased PAI-1 activity more in men than in women (-2.6 +/- 1.4 versus +0.9 +/- 0.9 IU ml(-1), P = 0.03). Men and women both showed increased t-PA activity with exercise training to the same extent (+0.38 +/- 0.12 versus +0.36 +/- 0.24 U ml(-1)). The changes in fibrinolytic measures with exercise training in men and women were correlated with changes in other fibrinolytic measures, although in men abdominal fat changes were a strong predictor of fibrinolytic changes with training. These findings suggest that training-induced improvements in endogenous fibrinolysis markers are somewhat greater in men compared to women and may be more strongly associated with abdominal obesity in men.

Effects of exercise and diet on chronic disease

Currently, modern chronic diseases, including cardiovascular diseases, Type 2 diabetes, metabolic syndrome, and cancer, are the leading killers in Westernized society and are increasing rampantly in developing nations. In fact, obesity, diabetes, and hypertension are now even commonplace in children. Clearly, however, there is a solution to this epidemic of metabolic disease that is inundating today's societies worldwide: exercise and diet. Overwhelming evidence from a variety of sources, including epidemiological, prospective cohort, and intervention studies, links most chronic diseases seen in the world today to physical inactivity and inappropriate diet consumption. The purpose of this review is to 1) discuss the effects of exercise and diet in the prevention of chronic disease, 2) highlight the effects of lifestyle modification for both mitigating disease progression and reversing existing disease, and 3) suggest potential mechanisms for beneficial effects.

Hypothesis: obesity and the insulin resistance syndrome play a major role in end-stage renal failure attributed to hypertension and labelled 'hypertensive nephrosclerosis'

About a third of new cases of renal failure in USA are attributed to hypertension despite controversy about the frequency and pathology of so called hypertensive nephrosclerosis. In spite of good documentation that obesity causes renal failure and in spite of the global epidemic of obesity this diagnosis does not feature on most renal failure registries. New documentation that progressive renal failure in hypertension is linked to insulin resistance and analysis of NHANES III data which shows a strong positive significant dose-response relationship between insulin resistance and chronic kidney disease strengthen the view that so called hypertensive nephrosclerosis may be linked more closely to obesity and insulin resistance than to blood pressure. The pathology of the kidney in hypertension has changed. Studies 50 years ago did not show segmental glomerulosclerosis, which has recently been shown to be the key lesion in hypertensive nephrosclerosis. Recent documentation that this is a major mechanism of progression in hypertension together with the fact that similar segmental glomerulosclerosis is the key lesion in obesity and the metabolic syndrome suggests that these factors are more important than hypertension in renal failure attributed to hypertensive nephrosclerosis.