Coagulation and fibrinolysis parameters in type 2 diabetic patients with and without diabetic vascular complications

Genetic variation in thrombin-activatable fibrinolysis inhibitor is associated with the risk of diabetic nephropathy

Diabetic nephropathy is a kidney disease or damage that results as a complication of diabetes, especially Type 2 diabetes, while albuminuria is an early marker for diabetic nephropathy as it can predict cardiovascular events and mortality in diabetic patients. A potent inhibitor of fibrinolysis, the thrombin-activatable fibrinolysis inhibitor (TAFI) has been isolated and characterized from human plasma. We investigated the associations of the activity-related variants in the TAFI coding gene (505A/G,1040C/T) with the risk of diabetic nephropathy by examining 297samples including 140 health controls and 157 confirmed diabetic nephropathy patients. Diabetic nephropathy grades were further categorized by the urine albumin excretion (UAE)-to-creatinine ratios (ACR). We found little difference that was statistically significant in terms of 505A/G among patients and controls. While at 1040C/T, the detected frequency for the T allele in the group of diabetic nephropathy patients was significantly smaller than that of the control group (15.6% vs 25.7%, respectively; p<0.05). This was due to the relative decrease of T/T homozygotes in the patients (p<0.05, 95% odds ratio 0.28, confidence interval 0.11-0.70). Surprisingly, the difference was only observed with initial diabetic nephropathy stages. This study clearly indicates that, at 1040C/T, the frequency for the T allele is strongly associated with increased risk for diabetic nephropathy in a subset of the general population, implying that the T allele confers protection against the onset of diabetic nephropathy only in homozygosity and may function as a recessive trait.

Effect of insulin sensitizer therapy on atherothrombotic and inflammatory profiles associated with insulin resistance

OBJECTIVE

To determine whether targeted pharmacological improvement of insulin sensitivity will normalize the associated elevations of thrombotic and inflammatory cardiovascular disease (CVD) biomarkers in individuals with insulin resistance.

PATIENTS AND METHODS

Study 1 was a cross-sectional study of Asian Indians with and without diabetes mellitus and Northern European Americans without diabetes (n=14 each) conducted between December 11, 2003, and July 14, 2006. Study 2 was a secondary analysis of a double-blind randomized controlled study conducted between August 19, 2005, and August 24, 2010, that included 25 individuals with untreated diabetes or impaired fasting glucose who were randomized to receive placebo (n=13) or a combination of metformin, 1000 mg twice daily, and pioglitazone, 45 mg daily (n=12), for 3 months. In both studies, measurements of insulin sensitivity (euglycemic-hyperinsulinemic clamp) and plasma inflammatory and thrombotic factor concentrations were obtained on enrollment (studies 1 and 2) and after intervention (study 2).

RESULTS

Study 1 demonstrated significant correlations between insulin sensitivity and plasma adiponectin, high-density lipoprotein cholesterol, plasminogen activator inhibitor 1, interleukin 6, tumor necrosis factor α, and triglycerides. Insulin sensitizer therapy significantly improved insulin sensitivity, inflammatory cytokines except interleukin 6, and thrombotic factors except fibrinogen, without concomitant changes in weight, blood pressure, or body composition.

CONCLUSION

Insulin sensitizer therapy ameliorates inflammatory and thrombotic factors implicated in developing CVD. Interventions to improve insulin sensitivity may thus be considered as therapeutic options to reduce CVD burden in insulin-resistant states, although further research is needed to determine long-term effects on morbidity and mortality.

Hemostasis effects of various glucose-lowering medications and angiopathy prevention

Aim. To assess hemostasis effects of various glucose-lowering medications (GLM), such as sulphanilamides, biguanides, and insulin, in regard to micro- and microangiopathy progression over 5 years in patients with Type 2 diabetes mellitus (DM-2). Material and methods. The study included 72 patients with DM-2 (47 women, 25 men; median age 54,0 years (49,0-59,0 years); mean DM-2 duration 4,0 years (0,5-8,0 years)), receiving one of the following GLMs for 5 years: glibenclamide, gliclazide, metformin, insulin, or the combination of glibenclamide and metformin. Results. Various GLMs had different effects on platelet activity. In the gliclazide group, aggregant activity was decreased, compared to the glibenclamide and insulin groups. In the metformin group, aggregant activity and platelet disaggregation were similar to that in the gliclazide group. The microangiopathy progression over 5 years was related to GLM therapy, being minimal in the DM-2 patients receiving metformin, and maximal among participants administered glibenclamide. The microangiopathy progression was minimal in the metformin and gliclazide groups, and maximal — in the glibenclamide group. Conclusion. Carbohydrate and lipid metabolism compensation is not the only condition of angiopathy prevention. The latter should be based on the complex intervention, aimed at the complete metabolic compensation and hemostasis balance. The need for taking pleiotropic activity of specific agents into consideration when choosing GLM therapy is emphasized by protective effects of metformin (micro- and microangiopathy prevention) and gliclazide (microangiopathy prevention), but not glibenclamide.

The Hemostatic System in Patients With Type 2 Diabetes With and Without Cardiovascular Disease

The contribution of the hemostatic system in the development of cardiovascular disease (CVD) in patients with type 2 diabetes is not completely defined. The aim of this study was to elucidate associations of hemostatic factors with the development of CVD in patients with type 2 diabetes. Patients with type 2 diabetes without CVD (n = 113), with CVD (n = 94), and controls without CVD (n = 100) were enrolled in this study. Several hemostatic markers were measured. A disturbed hemostatic balance in patients with type 2 diabetes was observed as illustrated by hypofibrinolysis and increased levels of von Willebrand factor (vWF) and plasminogen-activator inhibitor 1 (PAI-1). Patients with type 2 diabetes with CVD have more thrombin generation compared to patients without CVD. This hemostatic imbalance might contribute to the development of CVD in patients with type 2 diabetes.

Plasma thrombin-activatable fibrinolysis inhibitor (TAFI) antigen levels in diabetic foot ulcers

Plasma TAFI may participate in arterial thrombosis in cardiovascular diseases (CVD) and may be involved in the mechanism of vascular endothelial damage in diabetic patients. The aim of this study was to investigate the association of plasma TAFI antigen level in the development of diabetic foot ulcer in Type 2 diabetes. The TAFI antigen levels were determined in 50 patients with diabetic foot ulcers and 34 patients without diabetic foot ulcers and 25 healthy individuals. We measured TAFIa/ai antigen in plasma samples with a commercially available ELISA Kit. Diabetic foot ulcer group and diabetic group were similar in terms of mean age and sex distribution. Diabetes duration, retinopathy, neuropathy, macrovascular disease and infection were related to diabetic foot ulcers. HbA1c, HDL-cholesterol and Folic Acid levels were decreased in the diabetic foot ulcer group. TAFI levels were 99.44 ± 55.94% in control group, 135.21 ± 61.05% in diabetic foot ulcer group, 136.75 ± 59.38% in diabetic group and was statistically different (P < 0.05). But no difference was seen in TAFI levels between the diabetic foot ulcer group and diabetic group (P > 0.05). No significant difference in plasma TAFI levels were seen between diabetic foot ulcer stages. TAFI antigen levels are increased in Type 2 diabetic patients, but are not related to diabetic foot ulcer development.

Inflammatory, hemostatic, and other novel biomarkers for diabetic retinopathy: the multi-ethnic study of atherosclerosis

OBJECTIVE

There are conflicting data regarding relationships of systemic biomarkers of inflammation, hemostasis, and homocysteine with diabetic retinopathy. We examined these relationships in the Multi-Ethnic Study of Atherosclerosis.

RESEARCH DESIGN AND METHODS

A total of 921 participants with diabetes were included. Diabetic retinopathy was graded from retinal photographs. We defined two outcomes: any diabetic retinopathy and vision-threatening diabetic retinopathy (severe nonproliferative diabetic retinopathy or worse). Systemic markers analyzed were C-reactive protein, homocysteine, fibrinogen, plasmin-alpha(2)-antiplasmin complex (PAP), interleukin-6, d-dimer, factor VIII, serum creatinine, and urinary albumin-to-creatinine (UAC) ratio.

RESULTS

Prevalence of diabetic retinopathy was 33.2% and vision-threatening diabetic retinopathy 7.1%. After adjusting for established risk factors (diabetes duration, A1C, systolic blood pressure, waist-to-hip ratio, and use of diabetes medications), fibrinogen (odds ratio 1.14 [95% CI 1.01-1.32], P = 0.05) and PAP (1.25 [1.05-1.50], P = 0.01) were associated with any diabetic retinopathy, while PAP (1.54 [1.13-2.11], P = 0.007) and homocysteine (1.57 [1.16-2.11], P = 0.003) were associated with vision-threatening diabetic retinopathy. Only PAP remained significant after additional adjustment for serum creatinine and UAC ratio. Area under receiver-operator characteristic curve (AUROC) for diabetic retinopathy was constructed for established and novel risk factors. Established risk factors accounted for a 39.2% increase of the AUROC, whereas novel markers (fibrinogen, PAP, homocysteine, serum creatinine, and UAC ratio) only accounted for an additional 2.2%.

CONCLUSIONS

There were few associations of novel markers of inflammation, hemostasis, and homocysteine with diabetic retinopathy after controlling for established risk factors. These data suggest that there is limited clinical use of these biomarkers for prediction of diabetic retinopathy.

Effects of one year simvastatin and atorvastatin treatments on acute phase reactants in uncontrolled type 2 diabetic patients

Type 2 diabetes mellitus is the leading cause of macrovascular diseases and related death. Additionally, diabetes mellitus is frequently complicated by other cardiovascular risk factors, such as hypercholesterolemia, hypertension, obesity, hypercoagulability, and inflammation. We wanted to evaluate and compare the effects of treating with a one-year course of atorvastatin or simvastatin on inflammatory markers such as high sensitive C-reactive protein (hsCRP), fibrinogen, and ferritin in uncontrolled type 2 diabetic patients. Also, we planned to investigate the correlation between inflammatory markers and metabolic parameters. Fifty type 2 diabetic patients (30 women, 20 men; mean age: 49.9 +/- 8.5 years) were enrolled into the study. Twenty healthy subjects, matched on body mass index and age, were also included in the study as a control group. Diabetic patients were divided into two groups and received simvastatin or atorvastatin (Group S and A, respectively). After 1 year of statin treatment (Group A), there were significant decreases in total cholesterol (217.3 +/- 46.5-173.8 +/- 37.2 mg/dl; P < 0.0001), LDL-cholesterol (146.7 +/- 50.3-102.3 +/- 31.1 mg/dl, P < 0.0001), hsCRP (0.88 +/- 0.62-0.35 +/- 0.18 mg/dl, P < 0.0001), fibrinogen (258.2 +/- 16.9-215.5 +/- 10.6 mg/l; P < 0.0001), and ferritin (118.2 +/- 73.9-81.2 +/- 72.5 ng/ml, P < 0.0001) levels compared to basal values. In the S group, there were significant decreases in total cholesterol (224.4 +/- 61.2-175.0 +/- 47.8 mg/dl; P < 0.0001), LDL-cholesterol (140.9 +/- 56.7-110.9 +/- 42.2 mg/dl, P < 0.0001), hsCRP (0.98 +/- 1.3-0.46 +/- 0.25 mg/dl, P < 0.0001), fibrinogen (265.7 +/- 26.8-222.1 +/- 20.6 mg/l; P < 0.0001), and ferritin (136.7 +/- 101.1-85.6 +/- 32.1 ng/ml, P < 0.0001) levels compared to basal values. At the end of the study, hsCRP, fibrinogen, and ferritin levels were correlated with LDL (r = 0.42; P = 0.005, with hsCRP), (r = 0.40; P = 0.008, with fibrinogen), (r = 0.46; P = 0.002, with ferritin) and HDL (r = -0.50; P < 0.0001, with hsCRP), (r = -0.32; p = 0.042, with fibrinogen), (r = -0.48; P < 0.0001, with ferritin) cholesterol levels. Atorvastatin and simvastatin treatments were found to be effective for the control of hypercholesterolemia and resulted in a significant decrease in acute phase reactants in uncontrolled type 2 diabetic patients.

Diabetic retinopathy, PAI-1 4G/5G and -844G/A polymorphisms, and changes in circulating PAI-1 levels in Tunisian type 2 diabetes patients

AIM

The association of altered plasminogen activator inhibitor (PAI)-1 levels and PAI-1 polymorphisms (4G/5G and -844G/A) with diabetic retinopathy (DR) was investigated in 856 type 2 diabetes (T2D) patients, of whom 383 presented with (DR group), and 473 presented without (DWR group), retinopathy.

METHODS

PAI-1 4G/5G and -844G/A genotyping were done by PCR-RFLP, and PAI-1 levels were measured by ELISA testing.

RESULTS

The genotype distribution of 4G/5G and -844G/A polymorphisms did not deviate from the Hardy-Weinberg equilibrium model among healthy subjects. Higher frequencies of the 4G/4G genotype, and lower frequencies of the -844A allele, -844G/A and -844A/A genotypes, were seen in DR patients, conferring disease susceptibility and protection, respectively. While PAI-1 levels were significantly elevated in the 4G/4G compared with other PAI-1 genotypes, significant differences in PAI-1 levels between DR and DWR patients were seen in the 4G/-844A, 4G/-844G and 5G/-844A haplotype carriers among DR patients. However, comparable distributions of 4G/5G and -844G/A alleles, genotypes and haplotypes, and similar PAI-1 levels, were seen in the proliferative retinopathy (PR) and non-proliferative retinopathy (NPR) patients, indicating that neither PAI-1 variants nor changes in PAI-1 levels were linked to DR severity. Multivariate analyses identified 4G/-844A and 4G/-844G haplotypes as negatively and positively associated, respectively, with DR, but not with DR severity (PR vs NPR) after adjusting for a number of covariates.

CONCLUSION

The present study identifies changes in PAI-1 levels and genetic variations at the PAI-1 locus as risk factors for DR, but not DR severity, that may serve as useful markers of increased DR susceptibility.

Comparison of skin microvascular reactivity with hemostatic markers of endothelial dysfunction and damage in type 2 diabetes

Aim:

Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased cardiovascular risk due to an accelerated atherosclerotic process. The present study aimed to compare skin microvascular function, pulse wave velocity (PWV), and a variety of hemostatic markers of endothelium injury [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), tissue factor pathway inhibitor (TFPI), and the soluble form of thrombomodulin (s-TM)] in patients with NIDDM.

Methods:

54 patients with NIDDM and 38 sex- and age-matched controls were studied. 27 diabetics had no overt micro- and/or macrovascular complications, while the remainder had either or both. The forearm skin blood flow was assessed by laser-Doppler imaging, which allowed the measurement of the response to iontophoretically applied acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation), as well as the reactive hyperemia triggered by the transient occlusion of the circulation.

Results:

Both endothelial and non-endothelial reactivity were significantly blunted in diabetics, regardless of the presence or the absence of vascular complications. Plasma vWF, TFPI and s-TM levels were significantly increased compared with controls only in patients exhibiting vascular complications. Concentrations of t-PA and PAI-1 were significantly increased in the two groups of diabetics versus controls.

Conclusion:

In NIDDM, both endothelium-dependent and -independent microvascular skin reactivity are impaired, whether or not underlying vascular complications exist. It also appears that microvascular endothelial dysfunction is not necessarily associated in NIDDM with increased circulating levels of hemostatic markers of endothelial damage known to reflect a hypercoagulable state.

Whole blood aggregation, coagulation, and markers of platelet activation in diet-induced diabetic C57BL/6J mice

AIMS

Type 2 diabetes in humans is associated with hypercoaguability; however, little is known about platelet function in mouse models of type 2 diabetes used to study this disorder. Therefore, the purpose of this study was to examine platelet aggregation, coagulation, and markers of platelet activation in a diet-induced mouse model of type 2 diabetes.

METHODS

Four week old, male, C57BL/6J mice were randomized to a standard chow or high fat (60% beef lard) diet for 4 months. To examine platelet function we measured ADP-induced whole blood aggregometry, whole blood coagulation by thromboelastography, tail bleeding times, platelet microparticle and platelet expression of p-selectin and platelet expression of CD61 by flow cytometry.

RESULTS

Diabetic mice exhibited less aggregation (p<0.05), less coagulation (p<0.01), prolonged tail bleeding times (n.s.), and lower agonist stimulated platelet CD61 expression (p<0.001) compared to non-diabetic mice. There was no difference in platelet microparticle and platelet p-selectin expression.

CONCLUSIONS

Diet-induced type 2 diabetic mouse do not demonstrate the hypercoagulability and platelet activation typically observed in humans with this disorder. More studies are warranted to further explore platelet function in this mouse model; to determine their applicability for studying these alterations in type 2 diabetes.

The association of plasma fibrinogen concentration with diabetic microvascular complications in young adults with early-onset of type 2 diabetes

AIMS

Diabetic nephropathy is an important risk factor for cardiovascular diseases (CVD). The underlying etiology is not fully understood but may be related to changes in inflammatory and hemostatic markers with kidney disease. We investigated the associations of the markers with microvascular complications in Pima Indians (PI) with early-onset type 2 diabetes (T2DM).

METHODS

C-reactive protein, interleukine-6, fibrinogen, D-dimer, plasmin-antiplasmin complex and plasminogen activator inhibitor-1 were measured in 104 PI (age: 32+/-4 y) with diabetes and 59 (32+/-4 y) with fasting glucose <110 mg/dl and 2-h glucose <140 mg/dl. Urine albumin to creatinine ratio (ACR) was used as marker of nephropathy. Severity of retinopathy was classified in the worse eye by direct ophthalmoscopy as none, background and proliferative.

RESULTS

Of these markers, only fibrinogen was associated with ACR (r=0.25, p<0.01). After adjustment for age, sex, percentage Pima heritage, smoking status, diabetes duration, blood pressure and use of aspirin, antihypertensive and antihyperglycemic agents, general linear models (with natural log-transformed values of fibrinogen and ACR as dependent and independent variables, respectively) revealed that a one percent increase in ACR would yield a 0.02% increase in the fibrinogen (beta=0.02, p<0.05). Plasma fibrinogen was also significantly increased with severity of diabetic retinopathy (p<0.05).

CONCLUSIONS

Increased plasma fibrinogen concentration was associated with diabetic microvascular disease, in particular with nephropathy. This may help to explain the etiologic link between nephropathy and CVD.

Mechanisms of disease: the oxidative stress theory of diabetic neuropathy

Diabetic neuropathy is the most common complication of diabetes, affecting 50% of diabetic patients. Currently, the only treatment for diabetic neuropathy is glucose control and careful foot care. In this review, we discuss the idea that excess glucose overloads the electron transport chain, leading to the production of superoxides and subsequent mitochondrial and cytosolic oxidative stress. Defects in metabolic and vascular pathways intersect with oxidative stress to produce the onset and progression of nerve injury present in diabetic neuropathy. These pathways include the production of advanced glycation end products, alterations in the sorbitol, hexosamine and protein kinase C pathways and activation of poly-ADP ribose polymerase. New bioinformatics approaches can augment current research and lead to new discoveries to understand the pathogenesis of diabetic neuropathy and to identify more effective molecular therapeutic targets.

Chronic superior mesenteric venous thrombosis revealed by diabetic ketonuria and bacteremia

We report a patient with superior mesenteric venous thrombosis presenting as diabetic ketonuria and bacteremia. The patient was a 65-year-old man with a history of diabetes mellitus, and was admitted to our hospital due to high fever. Tests revealed diabetic ketonuria and Bacteroides fragilis bacteremia. Abdominal computed tomographic scan and Doppler sonography revealed an old thrombus in the superior mesenteric vein with good flow through collateral vessels, causing the patient to have an absence of abdominal symptoms. There was no evidence of hereditary thrombophilia. The thrombus was secondary to a combination of comorbidities, including dehydration, hyperosmolarity, and diabetes mellitus.

The pathophysiology of cardiovascular disease in diabetes mellitus and the future of therapy

Diabetes mellitus is a complex disease with several metabolic abnormalities leading to varied, interconnected endothelial and vascular dysfunction and resulting in accelerated atherosclerosis. Cardiovascular disease is the main cause of mortality in patients with diabetes. Apart from traditional therapy for control of hyperglycemia and other associated comorbidities, various newer therapies are being investigated to fight atherosclerosis at a molecular level. In this review, the authors briefly describe the pathophysiology of cardiovascular disease in patients with diabetes mellitus and the future of therapy.

Type 2 diabetes mellitus: a cardiovascular perspective

Diabetes mellitus is a disease, which is at the epitome of cardiovascular risk factors causing considerable morbidity and mortality. In addition to microvascular complications, there is two- to six-fold increased risk of macrovascular diseases, such as coronary artery disease, peripheral artery disease and stroke. While the mortality from coronary artery disease in patients without diabetes has declined over the past 20 years, the mortality in men with type 2 diabetes mellitus has not changed. Furthermore, the prevalence of diabetes in the UK has increased by 30% since 1991 and the same among the world population in 2010 is expected to be twice in 1990. This dramatic increase has serious implications from a cardiovascular perspective and thus the aggressive management of blood pressure, dyslipidaemia and blood glucose in diabetes is of vital importance. The aim of this review is to evaluate the current evidence and to discuss the implications of type 2 diabetes and its relevance to clinical practice in cardiology. We address this broad subject in discussing (i) the pathophysiology of cardiovascular disease in the setting of type 2 diabetes and (ii) the prevalence of cardiovascular risk, complications and prognostic implications in type 2 diabetes, with a discussion of current therapeutic interventions for the prevention or delay of these consequences where relevant.

Inflammatory, atherothrombotic aspects of type 2 diabetes

BACKGROUND

There is a tight association between diabetes and cardiovascular disease - both occur more commonly together than independently. The development of vascular disease is dependent upon complex interactions between a number of metabolic pathways involving both fluid phase proteins and cellular components. Inflammation and coagulation are two intimately linked processes that are co-regulated. The characteristic cluster of risk factors - hypertension, hyperinsulinaemia, hyperglycaemia and lipid abnormalities, which are associated with insulin resistance - have been expanded to include inflammation and thrombotic risk. Studies in patients with diabetes indicate a higher prevalence of both inflammatory cells and thrombosis in coronary plaques in comparison to non-diabetic subjects and measures of C-reactive protein predict the development of both diabetes and cardio vascular disease in prospective studies.

SCOPE

This review (based on MEDLINE searches, 1990 to 2005) looks at the inflammatory, atherothrombotic aspects of type 2 diabetes that may be involved in the accelerated development of vascular disease in the population with diabetes.