Haemostatic alterations in overweight children: associations between metabolic syndrome, thrombin generation, and fibrinogen levels

Plasma Heparin Cofactor II Activity Is Inversely Associated with Hepatic Fibrosis of Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus

AIMS

Thrombin exerts various pathophysiological functions by activating protease-activated receptors (PARs), and thrombin-induced activation of PARs promotes the development of non-alcoholic fatty liver disease (NAFLD). Since heparin cofactor II (HCII) specifically inactivates thrombin action, we hypothesized that plasma HCII activity correlates with the severity of NAFLD.

METHODS

A cross-sectional study was conducted. Plasma HCII activity and noninvasive clinical markers of hepatic fibrosis including fibrosis-4 (FIB-4) index, NAFLD fibrosis score (NFS) and aspartate aminotransferase-to-platelet ratio index (APRI) were determined in 305 Japanese patients with type 2 diabetes mellitus (T2DM). The relationships between plasma HCII activity and the clinical markers were statistically evaluated.

RESULTS

Multiple regression analysis including confounding factors showed that plasma HCII activity independently contributed to decreases in FIB-4 index (p＜0.001), NFS (p＜0.001) and APRI (p=0.004). In addition, logistic regression analysis for the prevalence of advanced hepatic fibrosis defined by the cutoff points of the clinical scores showed that plasma HCII activity was the sole and common negative factor for prevalence of advanced hepatic fibrosis (FIB-4 index: p=0.002, NFS: p=0.026 and APRI: p=0.012).

CONCLUSIONS

Plasma HCII activity was inversely associated with clinical hepatic fibrosis indices including FIB-4 index, NFS and APRI and with the prevalence of advanced hepatic fibrosis in patients with T2DM. The results suggest that HCII can serve as a novel biomarker for assessment of hepatic fibrosis of NAFLD in patients with T2DM.

Mediterranean products as promising source of multi-target agents in the treatment of metabolic syndrome

Alteration of nutritional habits play an essential role on the risk of developing Metabolic Syndrome (MetS). Several epidemiological studies have shown that assuming diets rich of foods included in the Mediterranean diet (MetDiet) pattern like, such as olive oil, nuts, fruit, fiber, vegetables, wine and grain cereals has protective effects on the different risk factors characterizing the MetS. The beneficial effects of the MetDiet in the MetS are mainly due to the antioxidant and anti-inflammatory properties of the most abundant phytochemical components of such foods as polyphenols like resveratrol and oleuropein, allyl sulfides, ellagic acid, mono- and poly-unsaturated fatty acids (MUFA and PUFA), tocopherols and flavonoids like quercetin, which have shown positive results in the prevention of cardiovascular diseases (CVDs), with related risk factors, like hypertension, hypercholesterolemia and obesity. In this review, we highlighted the multi-target activities of the bioactive components contained in some foods typical of the Mediterranean area like olive oil, onion, liquorice, rosemary, oregano, hazelnut, pistachio, "Melannurca" apple, red wine, hot pepper, Citrus sp. fruits, saffron and garlic, with particular focus on their impact on health outcomes in relation to MetS main key factors, such as insulin resistance (IR) and type 2 diabetes mellitus (T2DM), endothelial dysfunctions, inflammatory response, oxidative stress and dyslipidaemic and hypercholesterolemic effects.

Neutrophils and neutrophil-lymphocyte ratio: Inflammatory markers associated with intimal-media thickness of atherosclerosis

INTRODUCTION

Cardiac-cerebral vascular diseases (CCVDs) are global health problems due to the characteristic of high mortality. It is found that atherosclerosis (AS), a main cause of CCVDs, is significantly relevant to the change of intimal and media thickness. Neutrophil count (NEU) and neutrophil-lymphocyte ratio (N/L) are recognized possible risk factors for atherosclerosis (AS). However, there are few studies on the separate relationship between carotid intimal thickness, media thickness and NEU, N/L. This study explored the respective effects of NEU and N/L on AS and intimal, media thickness.

MATERIALS AND METHODS

The χ², Spearman's rho test, and multiple linear regression were implemented to analyze the relevance between blood parameters and intimal-media thickness. The potential factors, affecting non-depression time (NDT), is identified by univariate Cox regression. ROC curve was performed to determine the ability of blood parameters to predict intimal-media thickness. Immunohistochemistry was implemented.

RESULTS AND CONCLUSION

Based on χ², Spearman's rho test and multiple linear regression, NEU is related with intimal thickness (P < 0.05). Furthermore, NEU can predict the intimal thickness through the ROC curve. What's more, N/L is a risk factor of carotid media thickness (P < 0.05) by the Spearman's rho test, and is also correlated with poor NDT (P < 0.05) based on univariate Cox proportional regression analysis. Through ROC curve, N/L can predict the carotid media thickness. The carotid atherosclerotic endarterium is richest in macrophagocytes, and the arrangement of endotheliocytes is disordered. In summary, the increased NEU and N/L respectively have a strong correlation and precise predictability for carotid intimal and media thickness of atherosclerosis.

Obesity and risk for venous thromboembolism from contemporary therapy for pediatric acute lymphoblastic leukemia

INTRODUCTION

Acute lymphoblastic leukemia (ALL) therapy confers risk for venous thromboembolism (VTE) and associated acute and long-term morbidity. Obesity increases VTE risk in the general population but its impact on ALL therapy-associated VTE is unknown.

METHODS

In a retrospective cohort of children treated for ALL between 2008 and 2016 (n = 294), we analyzed obesity at diagnosis (body mass index [BMI] ≥95%) and subsequent development of VTE. A subset participated in two concurrent prospective ALL trials studying body composition via dual-energy X-ray absorptiometry (DXA) (n = 35) and hypercoagulability via thromboelastography (TEG) (n = 46). Secondary analyses explored whether precise measurement of body fat and/or global hemostasis ex vivo by TEG could further delineate VTE risk in the obese.

RESULTS

Overall, we found 27/294 (9.2%) patients developed symptomatic VTE during therapy, 19/27 (70%) occurred during Induction. Study-defined "serious" VTE developed in 4/294 (1.4%) of patients. Obesity but not overweight was strongly predictive of symptomatic VTE (obesity odds ratio = 3.8, 95% confidence interval 1.5-9.6, p = 0.008). In the DXA subset, only 2/35 patients developed symptomatic VTE. However, within those prospectively screened during Induction, 30% (14/46) developed VTE; eight (17%) of these were asymptomatic and found only via screening.

CONCLUSIONS

In this pediatric ALL cohort, obesity conferred more than a three-fold increased risk for symptomatic VTE. In a subgroup of patients who underwent active screening, up to a third were noted to have VTE (symptomatic and asymptomatic). TEG did not predict VTE. Additional studies are necessary to validate these findings and to further refine a risk-stratified approach to thrombo-prevention during ALL therapy.

Haemophilia A mutations in patients with non-severe phenotype associated with a discrepancy between one-stage and chromogenic factor VIII activity assays

About one-third of patients with non-severe haemophilia A (HA) show a discrepancy of factor (F)VIII activity (FVIII:C) measured by one-stage (FVIII:C1st), two-stage assays or the chromogenic method (FVIII:Cchr). The aim of the study was to characterise the mutation profile in patients with FVIII:C assay discrepancies. FVIII:C discrepancy was considered significant if the calculated ratio between FVIII:C1st and FVIII:Cchr was ≤ 0.6. In 16 patients FVIII:C1st was higher than FVIII:Cchr. The reverse phenomenon was observed in 83 patients. Genetic analysis revealed 23 different missense mutations of which 17 were novel. Most mutations, exhibiting a higher FVIII:C1st were localised in the A1-A2-A3 interface. The majority of mutations associated with FVIII:Cchr>FVIII:C1st discrepancy were located close to or within the thrombin cleavage sites, FIX or vWF binding sites. Our data show a correlation between FVIII:C and thrombin generation testing with a clear differentiation between patients with haemophilia and normal controls. However, in the subgroup of FVIII:C1st>FVIII:Cchr discrepancy, the endogenous thrombin potential and peak thrombin parameters were similar to non-discrepant haemophilia patients, while in the inverse discrepancy FVIII:Cchr>FVIII:C1st, these variables showed values close to that of the normal control group. Certain hereditary F8 mis-sense mutations cause discrepancy in FVIII:C as measured with different assays. This can lead to failure in diagnosing HA or incorrectly classifying the severity of the disease. Therefore, we recommend that initial diagnosis of non-severe HA phenotypes should be based on results of both FVIII:C1st and FVIII:Cchr assays.

Neutrophil-to-lymphocyte ratio: an inflammation marker related to cardiovascular risk in children

Low-grade chronic inflammation plays a pathogenic role in cardiovascular disease. An increase in the ratio of circulating neutrophils to lymphocytes (N/L ratio) may serve as a marker of cardiovascular risk in adults. It was the study objective to study whether N/L ratio associates with vascular parameters in children. Subjects were 501 prepubertal and early pubertal Caucasian children (mean age 8.0 years; mean body mass index (BMI) Z-score 0.2 ± 0.9; 266 boys and 235 girls) recruited within an ongoing population-based study. The subjects were stratified into three groups according to age. Neutrophil, lymphocyte, BMI, waist circumference, systolic blood pressure (SBP) and carotid intima-media thickness (cIMT), assessed in all children. The N/L ratio, derived from the absolute neutrophil and lymphocyte counts. In children aged < 7 years (n=190, all prepubertal), no associations were observed between N/L ratio and either anthropometric or cardiovascular parameters. In children aged 7–9 years (n=171, 1.7 % early pubertal), higher N/L ratio associated with higher BMI Z-score and waist circumference (p=0.008 to p< 0.0001). In children aged > 9 years (n=140, 29.2 % early pubertal), N/L ratio associated again with BMI Z-score and waist circumference and also positively with SBP and cIMT (all p=0.008 to p< 0.0001). These associations remained significant in linear regression models following adjustment for possible confounding variables such as age, gender, fasting triglycerides, C-reactive protein and puberty (and for SBP and cIMT, adjustment also for BMI). In conclusion, our results provide the first evidence that a higher N/L ratio is associated with a less favourable cardiovascular profile in children and delineate the development of these associations from late childhood onwards.

Increased plasminogen activator inhibitor results in a hypofibrinolytic state in adolescents with obesity: in vivo and ex vivo evidence

Obesity in adolescents increases their risk for deep vein thrombosis. The objectives of this study were to determine potential mechanisms for thrombotic risk by investigating the fibrinolytic pathway in a sample of adolescents with and without obesity. Thirty-seven adolescents with obesity and 16 normal weight age-matched controls were recruited. Plasma levels of components of the fibrinolytic system were measured in addition to a Global Haemostasis Potential assay (GHP), which assesses plasma capacity to generate and lyse a fibrin clot. Levels of plasminogen activator inhibitor (PAI) and tissue plasminogen activator (tPA)/PAI complexes were increased in adolescents with obesity when compared to normal weight controls. There was a significant inverse association of increasing PAI with a decrease in plasmin-antiplasmin complexes. The GHP in obese adolescents displayed a hypofibrinolytic response with a markedly increased t_½ clot lysis time, as well as an increase in fibrin clot density as indicated by increased absorbance at maximum peak height. In the obese group, immunodepletion of PAI decreased both t_½ lysis time and absorbance at maximum peak height. We have shown in vivo and ex vivo there is a hypofibrinolytic state in obese adolescents and have established the hypofibrinolytic state is due to increased PAI levels.

Fibrinogen: cardiometabolic risk marker in obese or overweight children and adolescents

OBJECTIVES

To determine the prevalence of increased serum fibrinogen levels and its association with cardiometabolic risk factors in overweight or obese children and adolescents.

METHODS

Cross-sectional study with 138 children and adolescents (overweight or obese) followed at a reference outpatient clinic of the public health care network. Fibrinogen concentration was divided into quartiles, and values above or equal to the third quartile were considered high. The association between high fibrinogen values and cardiometabolic risk factors was assessed using Pearson's chi-squared test or Fisher's exact test, as necessary. Logistic regression was used to adjust variables predictive of fibrinogen levels. Analyses were performed using SPSS version 22.0 and SAS software, considering a confidence interval of 95%.

RESULTS

Serum fibrinogen levels were elevated in 28.3% of individuals, showing association with the presence of high CRP (p=0.003, PR: 2.41, 95% CI: 1.30-4.46) and the presence of four or more risk factors (p=0.042; PR: 1.78, 95% CI: 1.00-3.17). After a logistic regression, only elevated CRP remained associated with altered fibrinogen levels (p=0.024; PR: 1.32; 95% CI: 1.09-5.25).

CONCLUSIONS

Increased fibrinogen was prevalent in the study population and was associated with ultrasensitive C-reactive protein and the presence of four or more cardiovascular risk factors; it should be included in the assessment of individuals at risk.

Changes in thrombin generation and D-dimer concentrations in women injecting enoxaparin during pregnancy and the puerperium

BACKGROUND

It is well accepted that the gravid state is hypercoagulable and a significant cause of both maternal morbidity and mortality in the Western world. Although thrombin generation is reported to be increased in pregnant women, uncertainty exists on the pattern of thrombin generation change during this time. The aim of this study is to describe thrombin generation changes and D-dimer concentrations in women injecting enoxaparin during pregnancy the postnatal period.

METHODS

One hundred and twenty-three women injecting enoxaparin had their thrombin generation, as measured by Calibrated Automated Thombinography (CAT), repeatedly assayed during pregnancy, once in each trimester, at delivery and 8 weeks post-partum. Furthermore, to understand the impact enoxaparin has on D-dimer concentrations during pregnancy, D-dimer concentrations were measured monthly in the recruited women.

RESULTS

Thrombin generation was found to increase in the first trimester (mean endogenous thrombin potential (ETP): 1391 nmol/L.min), further increasing during the second trimester (mean ETP: 1757 nmol/L.min), after which it plateaued through to delivery, where it peaked (mean ETP: 1857 nmol/L.min) and then fell back at 8 weeks post-partum (ETP: 1293 nmol/L.min). In contrast D-dimer concentrations increased exponentially during the antenatal period, despite the enoxaparin prescription.

CONCLUSION

Our results provide further evidence on alterations of thrombin generation during pregnancy and the postnatal period.

Significant associations between hemostatic/fibrinolytic systems and accumulation of cardiovascular risk factors in Japanese elementary schoolchildren

The aim of this study was to establish the reference values of hemostatic/fibrinolytic markers and investigate their relationship with physical constitution and cardiovascular risk factors in a normal schoolchildren population. This study comprised 148 healthy Japanese children aged 9-10 years (males 73; females 75). We performed laboratory tests including blood levels of leptin, high-sensitive C-reactive protein (hs-CRP), hemostatic and fibrinolytic markers [plasminogen activator inhibitor 1 (PAI-1), coagulation factor VII (FVII), coagulation factor X (FX), fibrinogen (Fbg), protein C, protein S], as well as common biochemical markers in the morning after an overnight fast. We investigated the mean, 10th, 50th and 90th percentile values of these markers. All parameters were compared between two groups, that is those with body mass index (BMI) 90th percentile or higher and BMI less than 90th percentile, and between subgroups based on the number of cardiovascular risk factors. Multiple-linear regression was used to assess associations between these hematological parameters and the components related to metabolic syndrome (MetS). Alanine aminotransferase (ALT), uric acid, leptin, hs-CRP, and all hemostatic/fibrinolytic markers (PAI-1, FVII, FX, Fbg, protein C, protein S) tested were significantly higher in the group with BMI 90th percentile or higher, and increased with accumulation of cardiovascular risk factors. Multiple-linear regression analysis showed that these values were associated with one or more components related to MetS. Reference values of hemostatic/fibrinolytic markers in Japanese schoolchildren were obtained. Many hemostatic/fibrinolytic markers showed significant association with BMI and accumulation of cardiovascular risk factors in normal Japanese schoolchildren.

Endogenous thrombin potential and examination of a further 31 analytes in liver transplant candidates

BACKGROUND

To predict the change in patient status and differentation of the basic diseases, endogenous thrombin potential (ETP), clinical chemistry, and coagulation variables were measured in liver transplant-listed patients with different etiologies.

METHODS

Differences in values of ETP and analytes of 30 control persons and 164 cirrhotic patients were examined by means of binary logistic regression. The relationship between the analytes and ETP parameters were analyzed by means of Spearman correlation. The different etiologies of cirrhosises were studied by factor and discriminant analyses. Binary logistic regression was applied to forecast changes in clinical status. Survival analysis was carried out with the appropriate variable.

RESULTS

International Normalized Ratio and activated partial thromboplastin time values were higher, whereas the area-under-the-curve values were lower in cirrhosis than in healthy subjects. A strong relationship was found only between the peak height and the anti-thrombin III (ATIII) values. In the factor analysis, 3 factors were found, which explained 81.6% of the total variance. Combination of aspartate aminotransferase and ATIII mostly separated the basic disease groups from each other in the discriminant analysis. From 35 variables, the lactate dehydrogenase (LDH) and ATIII have been suited for predicting the change in patient status. Eighty percent of patients with low ATIII and high LDH levels had deterioration of their clinical status.

CONCLUSIONS

Our study demonstrated that the ETP parameters did not provide additional information compared with "conventional" coagulation tests in cirrhosis. On the basis of our study, LDH and ATIII appear to be promising analytes to assess the clinical status of patients with cirrhosis. In our opinion, the classification system of liver transplant-listed patients can be improved with their use.

Thrombin inhibition with dabigatran protects against high-fat diet-induced fatty liver disease in mice

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of obesity and metabolic syndrome. Robust coagulation cascade activation is common in obese patients with NAFLD. We identified a critical temporal relationship between thrombin generation and the manifestation of hepatic steatosis, inflammation, and injury in C57BL/6J mice fed a high-fat diet (HFD) for 1, 2, and 3 months. Mice fed a HFD exhibited dramatic increases in hepatocellular injury and inflammation over time. Hepatic fibrin deposition preceded an increase in serum alanine aminotransferase, and the most dramatic changes in liver histopathology occurred in conjunction with a detectable increase in plasma thrombin-antithrombin levels at 3 months. To directly determine whether thrombin activity promotes NAFLD pathogenesis, mice were fed a HFD and simultaneously treated with the direct thrombin inhibitor dabigatran etexilate for 3 months. Notably, dabigatran treatment significantly reduced hepatic fibrin deposition, hepatic inflammation, hepatocellular injury, and steatosis in mice fed a HFD. Of interest, dabigatran treatment also significantly attenuated HFD-induced body weight gain. Gene expression analysis suggested that thrombin potentially drives NAFLD pathogenesis by altering the expression of genes associated with lipid metabolism and bile acid synthesis. Collectively, the results suggest that thrombin activity is central to HFD-induced body weight gain, liver injury, and inflammation and provide the proof-of-principle evidence that pharmacological thrombin inhibition could be effective in limiting NAFLD and associated pathologies.

Impact of obesity on the risk of venous thromboembolism in an inpatient pediatric population

INTRODUCTION

The incidence of venous thromboembolism in children has increased significantly over the past 20 years. Over the same period of time, there was an increase in the prevalence of obesity in the pediatric population. Obesity is a known risk factor for VTE in adults, but little information is available in children.

METHODS

This study evaluates the relation between obesity and VTE using a retrospective, case-control design, comparing the body mass index (BMI) of patients admitted with a diagnosis of VTE versus patients admitted with other diagnoses, at a single institution, between 2007 and 2011.

RESULTS

We studied 48 inpatients diagnosed with deep venous thrombosis or pulmonary embolism and a control group of 274 age and gender matched patients admitted with other diagnoses. We found obese patients (BMI > 95th percentile) to have significantly higher risk of VTE (odds ratio 2.1, with 95% CI 1.1-4.2) than patients of normal weight (BMI < 85th percentile). Overweight patients (BMI 85th-95th percentile) did not demonstrate a significant change in risk. Most of the VTE patients were adolescents and the majority of them had other identifiable risk factors for thrombosis.

CONCLUSION

This study establishes a correlation between obesity and VTE in a group of hospitalized children, showing a risk for VTE in obese children similar to the one described in much larger adult cohorts.

Thrombin generation in Cushing's Syndrome: do the conventional clotting indices tell the whole truth?

Cushing's Syndrome (CS) is associated with an increased mortality, where hypercoagulability seems to have a crucial role in both arterial and venous thrombosis. Parameters of in vitro thrombin generation (TG) such as lag time, peak thrombin and endogenous thrombin potential (ETP), that describe the time until thrombin burst, the peak amount of TG and the total amount of thrombin generated, respectively as well as classical clotting markers were evaluated in 33 CS patients compared to both a group of 28 patients matched for the features of Metabolic Syndrome (MetS) and 31 healthy individuals. CS and MetS patients had shorter lag time (p < 0.0001), higher peak and ETP (p < 0.0001) than healthy controls, though lag time was less shortened in CS (p < 0.0001) respect to MetS group. Prothrombin time (PT) was increased (p < 0.0001) in both CS and MetS patients, while partial thromboplastin time (PTT) was shorter (p < 0.0001) in CS compared to both MetS and healthy group (p < 0.0001). Factor VIII (FVIII), Antithrombin (AT), protein C and S were increased only in CS patients (p < 0.0001). lag time, AT and FVIII correlated to night salivary cortisol (r = + 0.59; p = 0.0005, r = + 0.40; p = 0.003, r = + 0.40; p = 0.04, respectively); PTT correlated inversely to urinary free cortisol (r = -0.45; p = 0.009). BMI correlated negatively to lag time (r = -0.40; p = 0.0001) and positively to peak and ETP (r = + 0.34; p = 0.001, r = + 0.28; p = 0.008, respectively). Obese and diabetic patients had shorter lag time (p = 0.0005; p = 0.0002, respectively), higher ETP (p = 0.0006; p = 0.007, respectively) and peak (p = 0.0003; p = 0.0005, respectively) as well as a more prolonged PT (p = 0.04; p = 0.009, respectively). Hypertensive individuals had higher ETP (p = 0.004), peak (p = 0.0008) and FVIII (p = 0.001). Our findings confirm a prothrombotic state in both CS and MetS patients, though lag time was less shortened in CS. The high levels of endogenous physiological anticoagulants, could possibly represent a protective mechanism against hypercoagulability seen in CS patients.

Individuals with coronary artery disease at a young age and features of the metabolic syndrome have an increased prothrombotic potential

The relation between coagulation and atherosclerosis has been extensively described, pointing towards a hypercoagulable state in patients with atherosclerosis, especially in young individuals. However, not all studies were conclusive. It is known that the metabolic syndrome (MetS), a risk factor for coronary artery disease (CAD), is related to a higher incidence of thrombo-embolic events. We hypothesised that individuals with CAD at a young age and MetS have an increased prothrombotic potential. It was the study objective to analyse the endogenous thrombin potential (ETP) and related thrombin generation parameters in patients with CAD before the age of 51 in men and 56 in women with and without MetS features and their healthy first-degree relatives. In this case-control study we included 118 CAD patients and 50 first-degree relatives (controls). Parameters of thrombin generation were obtained with calibrated automated thrombinography. An adjusted general linear model (GLM) showed a positive association between the peak thrombin levels and the presence of CAD at a young age. Based on the NCEP criteria we divided our patient group in CAD patients with and without MetS, and compared them to the controls without MetS. We showed that CAD patients with MetS have increased ETP levels, both in comparison with healthy first-degree relatives and with CAD patients without MetS. There were no differences in ETP between patients without MetS and healthy controls. In conclusion, this study shows that individuals with CAD at a young age and MetS features have an increased prothrombotic potential, compared to CAD patients without MetS.

Calculating cardiac risk in obese adolescents before and after onset of lifestyle intervention

Prevalence and severity of obesity in adolescents is increasing worldwide. The obesity-associated cardiovascular risk factors (CRF) determine cardiac risk as demonstrated by longitudinal studies. Fat distribution and not overall fat mass determines the cardiac risk, since intra-abdominal adipose tissue is especially related to CRFs. Besides classical CRFs such as hypertension, dyslipidemia and impaired glucose metabolism, a proinflammatory and prothrombotic state in obesity is associated with cardiac risk. Adipocytokines such as adiponectin are related to cardiac risk and may present useful predictors of cardiac mortalities in future. Measurement of the carotid intima-media thickness is a new promising noninvasive marker for early cardiovascular changes including atherosclerosis. The therapy of choice to prevent cardiac events in obesity is lifestyle intervention of obese adolescents. However, in clinical practice, the weight loss in lifestyle interventions is only moderate and drug treatment of CRFs is seldom performed.

Increased coagulation in childhood obesity

OBJECTIVE

This study aims to explore the relation between childhood obesity and procoagulant and anticoagulant systems.

METHOD

Fifty-one obese children and 32 normal-weighted children with similar age and gender distribution and between ages of 5 and 16 years were recruited to the study. Antropometric measures of all subjects, existence of any accompanying disease, and medication histories had been recorded. Full blood count, procoagulant, and anticoagulant coagulation tests were run for all subjects.

RESULTS

When hematologic variables of obese children were compared with those of healthy controls, it was found that average erythrocyte hemoglobin concentration, erythrocyte distribution width, and platelet count of obese children are significantly higher than healthy control group. It was also found that fibrinogen, thrombin time, factor (F) VIII, FIX, FX, and von Willebrand factor levels of obese children are higher than healthy control group. By contrast, antithrombin levels of obese children are found to be lower.

CONCLUSION

In our study, we found that there is a procoagulant increase in the coagulation system activity of obese children compared to non-obese healthy children, whereas there is a significant decrease in anticoagulant system. These changes occurred in obese patients, especially higher levels of plasma procoagulant factors such as fibrinogen, FVIII, FIX, and von Willebrand factor, lead us to think that there is an activity in these patients at endothelial level. Further studies are needed on endothelial activity of obese children.

Diet modulates endogenous thrombin generation, a biological estimate of thrombosis risk, independently of the metabolic status

OBJECTIVE

High endogenous thrombin potential (ETP) is associated with venous and arterial thrombosis. Better knowledge of environmental influences on ETP may help to prevent thrombosis.

METHODS AND RESULTS

Weaning rats exhibited high ETP values that decreased in low-fat diet and remained elevated on high-fat diet. In adult rats, high-fat diet-induced ETP increase was independent of coagulation factors, obesity, and insulin resistance and negatively associated with polyunsaturated fatty acid levels. Switching from high-fat diet to low-fat diet reversed the procoagulant phenotype with a slower kinetic than the normalization of hyperinsulinemia. In humans, ETP was independent of body weight whereas it was negatively associated with nutritional markers such as the percentage of energy provided by proteins, the protein:fat ratio, circulating phenolic compounds, and omega-3 polyunsaturated fatty acid. A recommended 3-month healthy diet with reduced energy density, including lipids, decreased ETP (-21%; P<0.0001). Changes in ETP were not associated with body weight, insulin sensitivity, or coagulation factor variations, but correlated negatively with plasma docosahexaenoic acid, a nutritional status sensitive fatty acid, and compounds reflecting vegetable intake.

CONCLUSIONS

Diet plays a pivotal role in regulating ETP, independently of obesity and insulin resistance. Global nutritional recommendations could be useful in primary prevention of venous thrombosis.

Inflammatory and prothrombotic states in obese children of European descent

Adipose tissue may release mediators that induce a chronic inflammatory state and alterations in coagulation, which contribute to insulin resistance, atherosclerosis, and thrombosis. We investigated whether inflammatory and/or prothrombotic states exist in obese children and assessed their interrelationship. Sixty-one subjects were recruited, aged between 6 and 16 years, to participate in a cross-sectional study at Children's University Hospital of Geneva. Selected pro/anti-inflammatory cytokines/chemokines and hemostasis parameters were measured in obese children and lean controls. Cardiovascular risk factors in the family were indexed. Fasting glucose level, insulin, prothrombin time (PT), fibrinogen, activated partial thromboplastin time (aPTT), D-dimer, endogenous thrombin potential (ETP), C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-γ-inducible-protein (IP-10), monocyte chemoattractant protein 1 (MCP-1), and interleukin-1 receptor antagonist (IL-1Ra) were measured. We estimated insulin resistance by homeostatic model assessment (HOMA). Anti- (IL-1Ra) and proinflammatory cytokines (MCP-1, IL-6) were significantly increased in obese children in comparison to the control group, even before puberty. Hemostasis was also altered in obese children with a significantly increased fibrinogen level, increased D-dimer, a shortened PT, as well as an increased ETP. No correlation was found between cytokine levels and hemostasis parameters, except for IL-6 and fibrinogen. Obese children present with inflammatory and prothrombotic states as early as 6 years of age and these states are similar in prepubertal and pubertal obese children. The cytokines IL-1Ra and MCP-1 were most significantly increased in obese children. Further investigation is necessary to determine if these cytokines, together with ETP, can reliably predict the development of diabetes and atherosclerosis.

Therapeutic administration of the direct thrombin inhibitor argatroban reduces hepatic inflammation in mice with established fatty liver disease

Thrombin generation is increased in patients with nonalcoholic fatty liver disease (NAFLD) and in mouse models of diet-induced obesity. Deficiency in the thrombin receptor protease activated receptor-1 reduces hepatic inflammation and steatosis in mice fed a Western diet. However, it is currently unclear whether thrombin inhibitors can modify the pathogenesis of established NAFLD. We tested the hypothesis that thrombin inhibition could reverse hepatic steatosis and inflammation in mice with established diet-induced NAFLD. Low-density lipoprotein receptor-deficient LDLr(-/-) mice were fed a control diet or a Western diet for 19 weeks. Mice were given the direct thrombin inhibitor argatroban ∼15 mg/kg/day or its vehicle via a miniosmotic pump for the final 4 weeks of the study. Argatroban administration significantly reduced hepatic proinflammatory cytokine expression and reduced macrophage and neutrophil accumulation in livers of mice fed a Western diet. Argatroban did not significantly impact hepatic steatosis, as indicated by histopathology, Oil Red O staining, and hepatic triglyceride levels. Argatroban reduced serum triglyceride and cholesterol levels in mice fed a Western diet. Argatroban reduced both α-smooth muscle actin expression and Type 1 collagen mRNA levels in livers of mice fed a Western diet, indicating reduced activation of hepatic stellate cells. This study indicates that therapeutic intervention with a thrombin inhibitor attenuates hepatic inflammation and several profibrogenic changes in mice fed a Western diet.

Thrombin generation in type 2 diabetes with albuminuria and macrovascular disease

BACKGROUND

Albuminuria is an indicator of cardiovascular morbidity and mortality in patients with type 2 diabetic mellitus (T2DM).

MATERIALS AND METHODS

In our cross-sectional study, we measured thrombin generation (TG), a key process in haemostasis and a tool to detect an individual's coagulation potential, in normo-, micro- and macroalbuminuria in T2DM with and without macrovascular disease (MVD). The TG-assay was performed, and the TG-curve [including the lag phase, peak thrombin and area under the curve (AUC)] was analysed.

RESULTS

A total of 160 patients (62 women; mean age ± SD: 67 ± 11 years) with T2DM and normo-, micro- or macroalbuminuria were investigated. Of those, 90 (56%) patients had normoalbuminuria, 40 (25%) microalbuminuria and 30 (19%) macroalbuminuria. The AUC between the groups of patients with normo-, micro- and macroalbuminuria was statistically significantly different [3297 (2785; 3764) vs. 3222 (2381; 3678) vs. 3726 (3153; 4235) nM Thrombin; P = 0AE019]. T2DM patients with MVD (n = 121) had a significantly shorter lag phase [12 (9; 16) vs. 20 (15; 25) min; P < 0AE001], a significantly higher peak thrombin [233 (130; 339) vs. 133 (82; 187) nM; P < 0AE001] and a significantly higher AUC [3464 (2969; 3868) vs. 3091 (2384; 3619) nM Thrombin; P = 0AE01] than T2DM patients without MVD (n = 39), indicating an earlier and higher thrombin generation.

CONCLUSION

Our results support the hypothesis that TG may be involved in the pathogenesis of MVD in diabetic nephropathy as for the first time, we could show that patients with T2DM in different stages of diabetic nephropathy had disturbances in thrombin generation.

Thrombin generation in clinical conditions

Commercial assays for determining thrombin generation in plasma are being tested in clinical conditions associated with thrombosis or bleeding. While pre-analytical conditions remain a source of inter laboratory variation, demanding for further standardization, clinical research proceeds. In patients at risk of venous thrombosis thrombin generation (TG) analysis may be utilized to detect underlying thrombophilia and this has been achieved both with addition of thrombomodulin or activated protein C, to test the contribution of the protein C system. In patients with documented venous thromboembolism, increased TG values are seen in those patients at greatest risk for recurrence, although the data are not consistent yet. In patients with arterial vascular disease, effects on TG patterns are seen that both reflect atherosclerosis (and its risk factors) and link to risk of recurrent atherothrombosis (coronary or stroke), but the data are limited. In patients with a bleeding diathesis, like hemophilia, the main importance of TG assays lies in the application for monitoring replacement therapy, either with factor concentrate or rFVIIa. An interesting application is in conjunction with thromboelastography, for monitoring peri-operative transfusion policy. Finally, TG analysis may contribute to monitoring anticoagulant drug treatment, but these and other applications would greatly benefit from whole blood, point of care applications of TG testing.

Trunk weighted obesity, cholesterol levels and low grade inflammation are main determinants for enhanced thrombin generation

OBJECTIVE

Endogenous thrombin generation (ETP) may be critically involved in obesity associated thromboembolism.

METHODS

Three hundred and one participants of the STyrian Juvenile OBesity (STYJOBS)/Early DEteCTion of Atherosclerosis (EDECTA) study cohort (age, 16-58years) were analysed. ETP was measured by the new CE-IVD marked Siemens-Innovance(®) ETP test on a BCS-XP analyser, and correlated to clinical findings and extended lipometry-based anthropometric data, biomarkers, and coagulation parameters.

RESULTS

In the overweight/obese study group, ETP and fibrinogen levels were significantly higher compared to controls (p<0.001). In a multiple stepwise regression including all subjects, subcutaneous adipose tissue thickness of upper back, cholesterol and ultrasensitive C-reactive protein were the best predictors for ETP.

CONCLUSION

Trunk weighted obesity together with low grade inflammation and hypercholesterolemia enhance thrombin generation.

Protease-activated receptor 1 and hematopoietic cell tissue factor are required for hepatic steatosis in mice fed a Western diet

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of obesity and metabolic syndrome and contributes to increased risk of cardiovascular disease and liver-related morbidity and mortality. Indeed, obese patients with metabolic syndrome generate greater amounts of thrombin, an indication of coagulation cascade activation. However, the role of the coagulation cascade in Western diet-induced NAFLD has not been investigated. Using an established mouse model of Western diet-induced NAFLD, we tested whether the thrombin receptor protease-activated receptor 1 (PAR-1) and hematopoietic cell-derived tissue factor (TF) contribute to hepatic steatosis. In association with hepatic steatosis, plasma thrombin-antithrombin levels and hepatic fibrin deposition increased significantly in C57Bl/6J mice fed a Western diet for 3 months. PAR-1 deficiency reduced hepatic inflammation, particularly monocyte chemoattractant protein-1 expression and macrophage accumulation. In addition, PAR-1 deficiency was associated with reduced steatosis in mice fed a Western diet, including reduced liver triglyceride accumulation and CD36 expression. Similar to PAR-1 deficiency, hematopoietic cell TF deficiency was associated with reduced inflammation and reduced steatosis in livers of low-density lipoprotein receptor-deficient mice fed a Western diet. Moreover, hematopoietic cell TF deficiency reduced hepatic fibrin deposition. These studies indicate that PAR-1 and hematopoietic cell TF are required for liver inflammation and steatosis in mice fed a Western diet.