fibrin and Diabetes-Mellitus--Type-1

Patients with type 1 diabetes form a less permeable fibrin network, which could contribute to their increased risk of cardiovascular disease (CVD). Low-dose aspirin treatment is the standard in the management of CVD; however, the effect seems reduced in patients with diabetes. We investigated the effects of low- and high-dose aspirin treatment on fibrin network formation in patients with type 1 diabetes (primary aim) and the possible interaction between the treatment effects of aspirin on fibrin network permeability and glycemic control in these patients (secondary aim).. Forty-eight patients (24 subjects with good [HbA(1c) <7.4%] and 24 subjects with poor [HbA(1c) >8.4%] glycemic control) were randomly assigned to treatment with 75 or 320 mg/day aspirin during 4 weeks in a crossover fashion. A 4-week washout period separated the treatment periods. The plasma fibrin network was assessed by determination of the permeability coefficient (K(s)).. Treatment with 75 mg aspirin did not influence fibrin network permeability (K(s)). However, K(s) increased significantly during treatment with 320 mg aspirin (P = 0.004), and a significant treatment effect was seen compared with treatment with 75 mg aspirin (P = 0.009). The increase in K(s) during high-dose aspirin treatment was significant in patients with poor glycemic control (P = 0.02), whereas K(s) only tended to increase in patients with good glycemic control (P = 0.06).. A high dose of aspirin is required to influence fibrin network permeability in patients with type 1 diabetes. The observed lack of effect with low-dose aspirin may contribute to aspirin treatment failure in diabetes.

Topics: Aspirin; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 1; Drug Administration Schedule; Female; Fibrin; Glycated Hemoglobin; Humans; Male

Diabetes is a prothrombotic state involving a more thrombogenic fibrin network. In the present study we investigated the effects of lipid-lowering therapy with atorvastatin on fibrin network structure and platelet-derived microparticles in patients with type 1 diabetes and dyslipidemia.. Twenty patients were treated with atorvastatin (80 mg daily) or placebo during 2 months in a randomized, double-blind, cross-over study. Fibrin network permeability, expression of glycoprotein IIIa, P-selectin and tissue factor on platelet-derived microparticles, plasma endogenous thrombin potential, plasminogen activator inhibitor-1 and tissue plasminogen activator antigen levels were assessed. Additionally, levels of plasma fibrinogen, high-sensitivity C-reactive protein and glycated haemoglobin were measured.. During treatment with atorvastatin, fibrin network permeability increased (p=0.01), while endogenous thrombin potential and expression of glycoprotein IIIa, P-selectin and tissue factor decreased (p<0.01). In vitro experiments indicated that platelet-derived microparticles influence the fibrin network formation as fibrin network permeability decreased significantly when platelet-derived microparticles were added to normal plasma. Baseline levels of plasminogen activator inhibitor-1 and tissue plasminogen activator antigen as well as plasma fibrinogen and high-sensitivity C-reactive protein were within reference values and not significantly changed during atorvastatin treatment, while glycated haemoglobin increased 0.3% (p<0.001).. Novel treatment effects were found in patients with type 1 diabetes and dyslipidemia during atorvastatin therapy, i.e. a more porous fibrin network, to which reduced expression of glycoprotein IIIa, P-selectin and tissue factor on platelet-derived microparticles may contribute. The observed impairment of glycemic control during long-term statin treatment deserves attention.

Topics: Adult; Aged; Atorvastatin; Biomarkers; Blood Platelets; C-Reactive Protein; Cell-Derived Microparticles; Cross-Over Studies; Diabetes Mellitus, Type 1; Double-Blind Method; Dyslipidemias; Fibrin; Fibrinolytic Agents; Glycated Hemoglobin; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Integrin beta3; Middle Aged; P-Selectin; Plasminogen Activator Inhibitor 1; Pyrroles; Sweden; Thrombin; Thromboplastin; Thrombosis; Time Factors; Treatment Outcome

Type 1 diabetes is a metabolic disorder caused by the loss or dysfunction of β-cells in the pancreas. Organ shortage is a critical concern of diabetic patients in need of beta islet transplantation. Tissue engineered islets are promising alternatives to traditional organ transplantation. Recent progress in stem cell biology and gene cloning techniques has raised hopes for the generation of insulin producing cells (IPCs) without the need of immunosuppression. The purpose of this study was to produce IPCs using human adipose-derived stem cells (hADSCs) and human endometrial-derived stem cells (hEnSCs) and also to compare the level of insulin secretion by these cells in 2D and 3D culture systems on fibrin scaffolding. Stem cells differentiation was carried out through transduction with an insulin over expression lentiviral vector. Real-time PCR and immunocytochemistry confirmed the successful transduction of both cell types. Both cell types showed comparable insulin secretion by ELISA.3D culture resulted in higher amounts of insulin secretion of the two cell types versus 2D as control. This study showed that insulin gene delivery to the stem cells could be an efficient method for producing IPCs and fibrin encapsulation enhances the functionality of these cells.

Topics: Adipose Tissue; Cell Differentiation; Cells, Cultured; Diabetes Mellitus, Type 1; Endometrium; Female; Fibrin; Gene Expression; Genetic Therapy; HEK293 Cells; Humans; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans Transplantation; Stem Cells; Tissue Scaffolds; Transduction, Genetic

Individuals with type-1 diabetes mellitus (T1DM) have a higher risk of thrombosis and low plasma magnesium concentrations. As magnesium is a known regulator of fibrin network formation, we investigated potential associations between fibrin clot properties and plasma magnesium concentrations in 45 individuals with T1DM and 47 age- and sex-matched controls without diabetes. Fibrin clot characteristics were assessed using a validated turbidimetric assay and associations with plasma magnesium concentration were examined. Plasma concentrations of fibrinogen, plasminogen activator inhibitor-1 (PAI-1), and lipids were measured and fibrin fiber diameters assessed using scanning electron microscopy. Fibrin clot maximum absorbance was unchanged in subjects with T1DM compared with controls, while lysis time was prolonged (

Topics: Adolescent; Adult; Blood Coagulation; Case-Control Studies; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinolysis; Glycated Hemoglobin; Homeostasis; Humans; Lipids; Lipoproteins; Magnesium; Male; Microscopy, Electron, Scanning; Nephelometry and Turbidimetry; Plasminogen Activator Inhibitor 1; Thrombosis; Young Adult

The increased risk of vascular complications in type 1 diabetes may in part be explained by changes in haemostatic function. In the present study, we investigated the fibrin clot properties in patients with type 1 diabetes in relation to sex and microvascular complications. The study included 236 patients (107 women) aged between 20-70 years and without any history of cardiovascular disease. Fibrin clot properties, assessed by determination of the permeability coefficient (Ks) and turbidimetric clotting and lysis assays, did not differ between men and women. Compared with men, women had worse glycaemic control as well as higher levels of prothrombin fragment 1+2 and peak thrombin generation in vitro, indicating increased thrombin generation both in vivo and in vitro. Subgroup analyses of patients younger than 30 years revealed less permeable fibrin clots and prolonged lysis time in females compared with age-matched men. Patients with microvascular complications had higher fibrinogen concentrations and denser and less permeable fibrin clots. Thus, we conclude that in vitro fibrin clot properties in patients with type 1 diabetes without cardiovascular disease are not different between the sexes, but associate with prevalence of microvascular complications. Tighter fibrin clot formation in younger women, as suggested by our results, may affect their future cardiovascular risk and should be investigated in a larger population.

Topics: Adult; Aged; Blood Coagulation; Blood Coagulation Tests; Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinogen; Fibrinolysis; Hemostasis; Humans; Hyperglycemia; Male; Microcirculation; Middle Aged; Nephelometry and Turbidimetry; Permeability; Risk Factors; Thrombin; Thrombosis; Young Adult

Diabetes is associated with various vascular complications and is suggested to induce a prothrombotic state. In the current study, we characterized antiplasmin incorporation into fibrin in relation to other fibrinolytic compounds in patients with type 1 diabetes.. A total of 236 patients with type 1 diabetes and 78 control subjects were investigated. The incorporation of antiplasmin into the fibrin network and the plasma levels of plasminogen activator inhibitor type 1 (PAI-1) activity, tissue plasminogen activator (tPA) activity, tPA/PAI-1 complex, plasmin-antiplasmin complex, antiplasmin, factor XIII, and d-dimer were measured. In addition, we used global assays to study fibrinolysis.. The incorporation of antiplasmin into the fibrin network was significantly higher in patients with type 1 diabetes than in control subjects without diabetes (1.65 ± 0.25 vs. 1.35 ± 0.18 mg/L, respectively; P < 0.0001). The patients also had lower PAI-1 activity (2.19 units/mL [interquartile range 0.96-5.42] vs. 4.25 units/mL [1.95-9.0]; P = 0.0012) and antiplasmin level in plasma (78.5 ± 13.3 vs. 83.2 ± 15.4 mg/L; P < 0.05), resulting in a higher fibrinolytic capacity (shorter clot lysis time; P = 0.0090). We did not find any important sex differences regarding fibrinolysis in the patients or in the control subjects.. Patients with type 1 diabetes incorporate more antiplasmin into the fibrin network than control subjects without diabetes do and have a reduced PAI-1 activity and a shorter clot lysis time. These results suggest that patients with type 1 diabetes produce a fibrin clot that is more resistant to fibrinolysis, which, however, may be counteracted by an increased fibrinolytic potential in plasma.

Topics: Adult; alpha-2-Antiplasmin; Case-Control Studies; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysin; Fibrinolysis; Humans; Male; Middle Aged; Plasminogen Activator Inhibitor 1; Tissue Plasminogen Activator

Topics: alpha-2-Antiplasmin; Diabetes Mellitus, Type 1; Female; Fibrin; Humans; Male

Topics: alpha-2-Antiplasmin; Diabetes Mellitus, Type 1; Female; Fibrin; Humans; Male

Impaired angiogenesis is a major clinical problem and affects wound healing especially in diabetic patients. Improving angiogenesis is a reasonable strategy to increase diabetes-impaired wound healing. Recently, our lab described a system of transient gene expression due to pegylated poly-l-lysine (PLL-g-PEG) polymer-mediated plasmid DNA delivery in vitro. Here we synthesized peptide-modified PLL-g-PEG polymers with two functionalities, characterized them in vitro and utilized them in vivo via a fibrin-based delivery matrix to induce dermal wound angiogenesis in diabetic rats. The two peptides were 1) a TG-peptide to covalently bind these nanocondensates to the fibrin matrix (TG-peptide) for a sustained release and 2) a polyR peptide to improve cellular uptake of these nanocondensates. In order to induce angiogenesis in vivo we condensed modified and non-modified polymers with plasmid DNA encoding a truncated form of the therapeutic candidate gene hypoxia-inducible transcription factor 1α (HIF-1α). HIF-1α is the primarily oxygen-dependent regulated subunit of the heterodimeric transcription factor HIF-1, which controls angiogenesis among other physiological pathways. The truncated form of HIF-1α lacks the oxygen-dependent degradation domain (ODD) and therefore escapes degradation under normoxic conditions. PLL-g-PEG polymer-mediated HIF-1α-ΔODD plasmid DNA delivery was found to lead to a transiently induced gene expression of angiogenesis-related genes Acta2 and Pecam1 as well as the HIF-1α target gene Vegf in vivo. Furthermore, HIF-1α gene delivery was shown to enhance the number endothelial cells and smooth muscle cells - precursors for mature blood vessels - during wound healing. We show that - depending on the selection of the therapeutic target gene - PLL-g-PEG nanocondensates are a promising alternative to viral DNA delivery approaches, which might pose a risk to health.

Topics: Amino Acid Sequence; Animals; Capillaries; Chlorocebus aethiops; COS Cells; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; DNA; Fibrin; Gene Expression Regulation; Gene Transfer Techniques; Hypoxia-Inducible Factor 1, alpha Subunit; Molecular Sequence Data; Neovascularization, Physiologic; Plasmids; Polyethylene Glycols; Polylysine; Rats; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A; Wound Healing

Impaired fibrin clot lysis is a key abnormality in diabetes and complement C3 is one protein identified in blood clots. This work investigates the mechanistic pathways linking C3 and hypofibrinolysis in diabetes using ex vivo/in vitro studies.. Fibrinolysis and C3 plasma levels were determined in type 1 diabetic patients and healthy controls, and the effects of glycaemia investigated. C3 incorporation into fibrin clots and modulation of fibrinolysis were analysed by ELISA, immunoblotting, turbidimetric assays and electron and confocal microscopy.. Clot lysis time was longer in diabetic children than in controls (599 ± 18 and 516 ± 12 s respectively; p < 0.01), C3 levels were higher in diabetic children (0.55 ± 0.02 and 0.43 ± 0.02 g/l respectively; p < 0.01) and both were affected by improving glycaemia. An interaction between C3 and fibrin was confirmed by the presence of lower protein levels in sera compared with corresponding plasma and C3 detection in plasma clots by immunoblot. In a purified system, C3 was associated with thinner fibrin fibres and more prolongation of lysis time of clots made from fibrinogen from diabetic participants compared with controls (244 ± 64 and 92 ± 23 s respectively; p < 0.05). Confocal microscopy showed higher C3 incorporation into diabetic clots compared with controls, and fully formed clot lysis was prolonged by 764 ± 76 and 428 ± 105 s respectively (p < 0.05). Differences in lysis, comparing diabetes and controls, were not related to altered plasmin generation or C3-fibrinogen binding assessed by plasmon resonance.. C3 incorporation into clots from diabetic fibrinogen is enhanced and adversely affects fibrinolysis. This may be one novel mechanism for compromised clot lysis in diabetes, potentially offering a new therapeutic target.

Topics: Adolescent; Adult; Blood Coagulation Disorders; Blood Coagulation Tests; Case-Control Studies; Complement C3; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male

The aim of this study was to determine whether local insulin delivery using a fibrin gel (FG) loaded with insulin/poly(lactic-co-glycolic acid) microspheres (FGIPM) improves the biomechanical retention of titanium implants in type 1 diabetic rats.. Rats were divided randomly into 8 groups: a group of healthy rats (no treatment), a group of diabetic rats (no treatment), and 6 groups of diabetic rats treated locally using carriers containing or not containing insulin. Rats received implants in the tibia and were allowed to heal for 4 or 8 weeks. Removal torque tests (RTQ) were performed to evaluate the biomechanical retention of the implants.. In the diabetic control group, the mean RTQ values were significantly decreased compared with those for the healthy group. The local application of FGIPM increased the RTQ values in diabetic rats to the values found in the healthy rats at 8 weeks. The FG-treated group presented statistically significant higher mean RTQ values than the diabetic rats receiving no treatment.. Local insulin delivery using FGIPM ameliorated the biomechanical retention of titanium implants in type 1 diabetic rats and the FG had a beneficial effect.

Topics: Administration, Topical; Animals; Biomechanical Phenomena; Delayed-Action Preparations; Dental Implants; Dental Materials; Dental Prosthesis Retention; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Drug Carriers; Drug Delivery Systems; Fibrin; Hypoglycemic Agents; Insulin; Lactic Acid; Male; Microscopy, Electron, Scanning; Microspheres; Placebos; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Random Allocation; Rats; Rats, Wistar; Streptozocin; Time Factors; Titanium; Torque

The cellular and molecular mechanisms and safety after drug-eluting stent (DES) implantation in diabetic patients are still poorly understood; therefore, in this study, we evaluated the pathologic responses of the sirolimus-eluting stent (SES) or paclitaxel-eluting stent (PES) in a type I diabetes mellitus (DM) rat model.. The type I DM rat model was manipulated by intra-peritoneal streptozotocin injection. Two weeks later, DES was implanted in the aorta of rats with hyperglycemia or not as a control. Four weeks after DES implantation, the stented aorta was isolated and histomorphometric analysis was performed.. On histomorphometric analysis, increased thrombus, inflammatory cell infiltration, and neointimal hyperplasia (NIH) without change of the smooth muscle cell number after DES implantation were observed in DM rats compared with non-DM (NDM) rats. Furthermore, delayed coverage of mature endothelial cells defined as a von Willebrand factor expression and increased immature endothelial cells as a c-kit expression after DES implantation were observed in DM rats compared with NDM rats. Increased fibrin deposition and decreased hyaluronic acid accumulation at NIH after DES implantation were also observed in DM rats compared with NDM rats.. In conclusion, the main mechanism of restenosis after DES implantation under hyperglycemic conditions was initial thrombus with changes of the extracellular matrix rather than SMC proliferation. These results provided a therapeutic clue for the selection of DES and application of combination therapy using anti-thrombotic and anti-inflammatory drugs in diabetic patients.

Topics: Animals; Anti-Inflammatory Agents; Aorta; Body Weight; Coronary Restenosis; Diabetes Mellitus, Type 1; Disease Models, Animal; Drug-Eluting Stents; Fibrin; Humans; Hyaluronic Acid; Hyperglycemia; Inflammation; Male; Paclitaxel; Rats; Rats, Sprague-Dawley; Sirolimus; Thrombosis

Topics: Aged; Case-Control Studies; Diabetes Mellitus, Type 1; Fibrin; Gels; Hematologic Tests; Humans; Middle Aged; Permeability; Porosity; Reproducibility of Results

Patients with Type 1 diabetes have a tighter plasma fibrin gel structure, to which impaired glycemic control might contribute. Improved glycemic control can be achieved with continuous subcutaneous insulin infusion (CSII).. The aim of the present study was to investigate the effect of CSII on plasma fibrin gel properties and circulating markers of inflammatory activity in patients with Type 1 diabetes.. Twenty-eight patients were investigated before and after 4-6 months' treatment with CSII. Fibrin gel structure formed in vitro from plasma samples was investigated by liquid permeation of hydrated fibrin gel networks. P-fibrinogen was analyzed by a syneresis method. Comparisons were made between patients with improved (> 0.5%) and unchanged (< 0.5%) glucosylated hemoglobin (HbA1c) during CSII.. Eighteen patients showed improved and 10 patients unchanged HbA1c during CSII. P-fibrinogen, high sensitive C-reactive protein and serum amyloid A-antigen were not significantly changed, while fibrin gel permeability (Ks) and fiber mass-length ratio ( micro ) increased in both groups (P < 0.02). P-insulin and triglycerides decreased (P < 0.05) in both groups, while reductions of total cholesterol and intercellular adhesion molecule-1 were seen only in patients with improved HbA(1c) (P < 0.05). Absolute changes in Ks were inversely correlated to changes in plasma fibrinogen (r = 0.50; P < 0.01) and in LDL-cholesterol (r = 0.46; P < 0.05).. Treatment with CSII in patients with Type 1 diabetes is associated with increased plasma fibrin gel porosity. Slight attenuation of the inflammatory activity was also observed. The changes in fibrin gel porosity seem to be mainly mediated by changes in plasma fibrinogen and blood lipids, and are probably secondary to improved insulin sensitivity.

Topics: Adolescent; Adult; Biomarkers; Cell Adhesion Molecules; Chemokines; Cytokines; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinogen; Glycated Hemoglobin; Hematologic Tests; Humans; Inflammation; Infusions, Parenteral; Insulin; Lipids; Male; Porosity

We investigated thrombin activatable fibrinolysis inhibitor (TAFI) and its influence on fibrinolysis by measuring pro-TAFI activity and total TAFI antigen in 38 patients with type I diabetes mellitus (18 with and 20 without microvascular complications), as well as in 20 healthy controls. The pro-TAFI levels in the two groups of patients did not differ from those in the control group. Total TAFI antigen [i.e. pro-TAFI, TAFI and inactive carboxypeptidase U (TAFIi)] tended to decrease in both the patient groups (59.7 +/- 7.2 and 73.4 +/- 8.9% with and without microvascular complications, respectively) compared with controls (91.9 +/- 12.2%) (P = 0.12). We also assessed the overall hemostatic potential (OHP) in plasma, the clot lysis time and the overall fibrinolytic potential. The OHP was significantly higher in patients with complications compared with controls (8.9 +/- 0.9 versus 6.7 +/- 0.4; P < 0.05) and also higher in the diabetics without complications (7.8 +/- 0.6), although the latter difference did not reach statistical significance. Levels of clot lysis time and overall fibrinolytic potential were similar in the two groups of patients and the controls. The increased OHP in plasma from diabetic patients with microvascular complications indicates an imbalance of the hemostatic system towards a prothrombotic state. No signs of impaired fibrinolysis were observed in patients with diabetes. Using the OHP method for estimation of overall hemostasis, it seems that TAFI does not influence either fibrinolysis or the increased thrombotic potential observed in patients with type I diabetes mellitus.

Topics: Adult; Carboxypeptidase B2; Case-Control Studies; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinolysis; Hemostasis; Humans; Male; Microcirculation; Middle Aged; Thrombophilia

Topics: Diabetes Mellitus, Type 1; Fibrin; Fibrinogen; Fibrinolysis; Gels; Humans; Immunoassay; Macromolecular Substances; Reference Values

Collagen IV matrix of glomerular basement membrane may be involved in the development of various renal diseases, e.g. diabetic nephropathy. An immunoblotting method for the detection of the carboxy-terminal non-collagenous (NC1) domain of type IV collagen in plasma was developed. The high sensitivity down to the picogram range enabled characterization of NC1(IV) fragments in human blood for the first time. Both Western blotting and gel filtration chromatography coupled with an enzyme-linked immunoassay surprisingly revealed that the NC1(IV)-related components are bound to the fibrin clot forming during blood coagulation. About 40% of the NC1(IV) fragments in plasma had an apparent molecular mass higher than 340,000. Abnormal NC1(IV) immunoblot patterns were observed in about 50% of patients with insulin-dependent (n = 20) and non-insulin-dependent (n = 20) diabetes mellitus compared with less than 7% in healthy control subjects (n = 30). There were no obvious associations between abnormal immunoblots and stage of nephropathy or glycaemic control in diabetic subjects.

Topics: Adult; Aged; Antibodies; Antigens; Binding, Competitive; Blood Coagulation; Blood Glucose; Blotting, Western; Chromatography, Gel; Collagen; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Female; Fibrin; Humans; Male; Middle Aged; Protein Structure, Tertiary; Sensitivity and Specificity

High plasma fibrinogen levels are associated with vascular complications in the general population. Fibrin, the structural element in a clot, is derived from fibrinogen by activation of thrombin. An abnormal fibrin gel structure has been demonstrated in patients with myocardial infarction and in diabetic patients during poor metabolic control. In the present study the properties of fibrin gel structure were investigated in 20 patients with insulin-dependent diabetes mellitus (IDDM): 10 patients without (age: 30 +/- 8; diabetes duration: 7 +/- 6 years), and 10 patients (age: 44 +/- 7; diabetes duration: 27 +/- 9 years) with microangiopathy. Fifteen healthy subjects served as controls (age: 40 +/- 8 years). The glycosylated haemoglobin level (HbA1c) was elevated (p < 0.001) in the patients: 6.5 +/- 1.5% in diabetic patients without, and 7.1 +/- 1.0% in diabetic patients with microangiopathy. C-reactive protein and plasma fibrinogen were similar as compared to healthy control subjects. The properties of the fibrin gel structure; i.e. the permeability coefficient (Ks) and the fibre mass length ratio (mu) formed in recalcified plasma on addition of thrombin were investigated. Ks was decreased in the diabetic patients, with (6.5 +/- 2.0 cm2; p < 0.01) and without microangiopathy (6.5 +/- 2.7 cm2; p < 0.05), as compared to healthy subjects (10.0 +/- 3.4 cm2), while mu was not significantly (p = 0.14) altered. The results indicate a lower fibrin gel porosity in patients with IDDM, despite normal plasma fibrinogen and irrespective of microangiopathy. The abnormal fibrin gel structure may be due to an increased glycosylation of the fibrin (-ogen) molecule caused by long-term hyperglycaemia and may be of importance for the development of angiopathy in diabetic patients.

Topics: Adult; Coagulants; Cohort Studies; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinogen; Gels; Glycated Hemoglobin; Humans; Male; Middle Aged; Thrombin

Topics: Adult; Blood Coagulation; Blood Proteins; Chromatography, Gel; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male; Protein Denaturation

Diabetic patients are prone to develop vascular complications. Increased procoagulatory factors and a reduced fibrinolytic potential are considered as thrombogenic risk factors, although controversy remains. In epidemiological and dietary intervention studies fish or fish oil, rich in the two n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have demonstrated a potential to reduce cardiovascular disease. We compared the plasmatic coagulatory and fibrinolytic profile of 13 near normoglycaemic type I diabetics almost free of cardiovascular disease with healthy volunteers, matched for age and sex. Except for fibrinogen levels and tPA activity being elevated and soluble fibrin and fibrinopeptide A being reduced, no differences could be discerned between type I diabetics and controls in all investigated plasmatic parameters. In a dietary intervention study we investigated the effects of 5.4 g EPA and 2.7 g DHA per day during and after a 4-week dietary supplementation in the diabetic patients. The factors, inhibitors and activation products of coagulation and fibrinolysis measured were at best transiently affected by the diet. Only plasminogen activator inhibitory activity in plasma significantly increased during the dietary supplementation and returned to prediet values after cessation of n-3 fatty acids. Changes in PAI activity were negatively correlated to changes in serum triglycerides. We conclude that well adjusted type I diabetics show an almost unchanged haemostatic profile compared to matched healthy controls. A dietary intervention with n-3 fatty acids in these patients does not affect the plasmatic haemostatic pattern except for an increase in PAI activity.

Topics: Adult; Arteriosclerosis; Diabetes Mellitus, Type 1; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Eicosapentaenoic Acid; Female; Fibrin; Fibrinogen; Fibrinolysis; Fibrinopeptide A; Hemostasis; Humans; Male; Plasminogen Inactivators; Tissue Plasminogen Activator

One hundred and fourty-eight insulin-dependent diabetic patients were available for this study; 56 males and 92 females. For the investigation of coagulation activation we determined activated partial thromboplastin time, thrombin time, and fibrinogen besides fibrin monomers and thrombin-antithrombin III complexes (TAT-III). We assessed large percentages of increased fibrinogen levels but non-significant increases of the mean values in comparison with the reference group. The values for thrombin time were significantly prolonged, although relatively small percentages were exceeding the reference range. For the activated partial thromboplastin time, the values exceeded the upper reference limit, and the mean values were significantly higher than those of the reference group. Also for the fibrin monomers we obtained often enhanced values, and moreover, the values were significantly higher as compared with the reference subjects. The amount of TAT-III concentrations above the reference range was much smaller than for the fibrin monomers and the TAT-III levels were not significantly enhanced. The results presented here are indicative of coagulation activation in diabetics, as indicated by the fibrin monomers and more or less by the TAT-III levels. Moreover, there could be demonstrated a positive correlation between fibrin monomer levels and HbA1 concentrations.

Topics: Adult; Aged; Aged, 80 and over; Antithrombin III; Blood Coagulation; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinogen; Glycated Hemoglobin; Humans; Male; Middle Aged; Partial Thromboplastin Time; Peptide Hydrolases; Sex Factors; Thrombin Time

To investigate the effect of blood glucose concentration on thrombin generation and fibrinolytic activity, six Type 1 patients had the blood glucose concentration maintained for 1 h at 5, 15, and 25 mmol l-1, and 8 patients underwent hypoglycaemia of 20 min duration after the blood glucose had been kept at 8 mmol l-1 for 1 h. During hyperglycaemia plasminogen activator activity rose from 214 (11-625) (median, range) to 478 (18-772) units (p less than 0.05) at a blood glucose of 5 mmol l-1 and to 511 (89-816) (p less than 0.05) and 535 (33-976) (p less than 0.05) units at a blood glucose of 15 and 25 mmol l-1, respectively. Cross-linked fibrin degradation products (FDP) were 45 and 53 micrograms l-1 at a blood glucose of 5 mmol l-1 and remained unchanged at higher glucose levels. Fibrinopeptide A was 1.3 (0.6-2.8) nmol l-1 at a blood glucose of 5 mmol l-1, and remained unchanged with hyperglycaemia, being 1.3 (0.9-1.3) nmol l-1 after 1h at 25 mmol l-1. During hypoglycaemia, plasminogen activator activity rose from 155 to 745 units (p less than 0.05) while both fibrinopeptide A and cross-linked FDP remained unchanged. The results indicate that acute fluctuations in blood glucose concentration do not lead to thrombin generation. Additionally, increased fibrinolytic activity measured in vitro is not associated with an increase in cross-linked FDP. This suggests that short-term hyper- and hypoglycaemia do not affect the end-products of the coagulation and fibrinolytic pathways.

Topics: Blood Glucose; Diabetes Mellitus, Type 1; Fibrin; Fibrinopeptide A; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Male; Plasminogen Activators; Thrombin

Polymerisation and crosslinking of fibrin monomers was studied in 35 healthy volunteers and in 42 poorly controlled diabetic patients. Polymerisation did not show any difference between control subjects (n = 10) and diabetic patients (n = 11) (p greater than 0.1), although fibrinogen was 35% more glycated in the diabetic patients (p less than 0.001). Alpha chain crosslinking in the diabetic patients, however, was impaired as is shown from an increase in intermediate alpha polymers with a concomitant decrease in alpha monomer disappearance. A significant positive correlation was found between the degree of glycation of fibrinogen and the defective alpha chain polymerisation (r = 0.86, p less than 0.005). These results were consistent with the results of thrombin and reptilase experiments. The reaction rate with reptilase did not show any difference between the two groups (p greater than 0.1), whereas the reaction rate with thrombin was significantly slower in the diabetic group compared to the control subjects (p less than 0.001). Purified fibrin clots obtained from the diabetic patients were more susceptible to plasmin than clots obtained from control subjects. It is concluded that in poorly controlled diabetic patients polymerisation of fibrin monomers is normal, but crosslinking of the alpha chains is impaired, leading to a higher susceptibility of the clots to plasmin degradation.

Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 1; Fibrin; Fibrinogen; Glycated Hemoglobin; Humans; Kinetics; Macromolecular Substances; Middle Aged; Reference Values

Cultured endothelial cells (EC) from the umbilical veins of infants of non-diabetic mothers induced retraction of fibrin clots formed by addition of thrombin to cell-free plasma. Fibrin clot retraction activity increased with time, reaching a maximum within 24 hours and was inhibited at 4 degrees C or in the presence of EDTA. This retraction had many characteristics in common with that induced by platelets. EC obtained from the umbilical veins of infants of poorly controlled insulin dependent diabetic mothers (IDDM) showed similar patterns of retraction. However, compared to normals, these cells induced greater retraction. Since the retraction of fibrin clots is thought to promote the exposure of sub-endothelial layers and since such an exposure plays a major role in thrombogenesis, we suggest that retraction of fibrin clot by EC should be taken into account in evaluating pre-thrombotic states.

Topics: Cells, Cultured; Clot Retraction; Diabetes Mellitus, Type 1; Endothelium; Female; Fibrin; Humans; Infant, Newborn; Pregnancy; Pregnancy in Diabetics; Time Factors; Umbilical Veins

Fibrinogen was purified from plasma from 22 non-diabetic and 26 poorly controlled Type 1 (insulin-dependent) diabetic subjects. In non-diabetic subjects, 0.95 +/- 0.17 mol glucose was bound per mol fibrinogen, whereas in the diabetic subjects 1.33 +/- 0.21 mol glucose was bound per mol fibrinogen (mean +/- SD, p less than 0.001). Comparison of the amount of bound glucose, when estimated by two different methods, suggested that lysine is the site of glycosylation. It is currently unknown whether this increased glycosylation of fibrinogen alters its function.

Topics: Adult; Binding Sites; Blood Glucose; Diabetes Mellitus, Type 1; Female; Fibrin; Fibrinogen; Humans; Lysine; Male; Middle Aged

The presence of soluble fibrin complexes (SFC) measured by gel filtration of plasma on 4% agarose columns, fibrinogen heterogeneity on 3.5% SDS-polyacrylamide gels and the concentrations of several plasma proteins were evaluated in 39 patients with diabetes mellitus (DM) and 19 matched control subjects. A small but significant increase of SFC was found in DM (p less than 0.01). On individual basis 51.2% of the patients had increased SFC (greater than M + 2 SD of the controls). Polyacrylamide gel electrophoresis of the SFC showed no evidence of cross-linking or proteolysis. Plasma clots formed in the presence of EDTA and trasylol were analysed in SDS-polyacrylamide gels in a normal and two lower molecular weight fibrin bands (band I, II, III). The percentage of band I fibrinogen was in diabetics (65.3 +/- 4.7%) lower than that of the controls (71.8 +/- 4.5%) (p less than 0.01). Fibrinogen levels, antithrombin III, alpha 1-antitrypsin, alpha 2-macroglobulin and plasminogen were significantly increased in DM. We suggest that in DM there is an enhancement of intravascular fibrin formation and accelerated fibrinogen degradation to lower molecular weight forms.

Topics: Adolescent; Adult; Aged; alpha 1-Antitrypsin; alpha-Macroglobulins; Antithrombin III; Blood Coagulation; Chromatography, Gel; Diabetes Mellitus; Diabetes Mellitus, Type 1; Disseminated Intravascular Coagulation; Electrophoresis, Polyacrylamide Gel; Female; Fibrin; Fibrinogen; Humans; Male; Middle Aged; Plasminogen; Solubility

Preliminary evidence has suggested that somatostatin might interfere with platelet function in the baboon. Because this agent is currently being administered experimentally to human beings, we studied its effect on coagulation and platelet function in man. In five subjects, a four-hour infusion of somatostatin (500 micrograms per hour) had no definite effect on platelet count, leukocyte count, hematocrit, platelet adhesiveness and aggregation, bleeding time, partial thromboplastin time, prothrombin time, and fibrinogen levels. A similar infusion for 18 hours in three subjects was likewise without effect. These studies indicate that somatostatin does not affect coagulation and platelet function in man and that its prolonged administration lacks ostensible toxicity.

Topics: Adenosine Diphosphate; Adult; Blood Cell Count; Blood Coagulation; Blood Coagulation Tests; Blood Glucose; Blood Platelets; Collagen; Diabetes Mellitus, Type 1; Drug Evaluation; Epinephrine; Female; Fibrin; Fibrinogen; Glucagon; Hematocrit; Humans; Infusions, Parenteral; Leukocyte Count; Male; Platelet Adhesiveness; Platelet Aggregation; Prothrombin Time; Serotonin; Somatostatin

Topics: Adult; Age Factors; Aged; Arteries; Blood Flow Velocity; Blood Pressure; Blood Vessels; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Diabetic Retinopathy; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Leg; Male; Middle Aged; Obesity; Plasminogen; Plethysmography, Impedance; Regional Blood Flow; Thrombophlebitis

Topics: Adolescent; Adult; Aged; Arteriosclerosis; Blood Coagulation Disorders; Blood Coagulation Tests; Diabetes Complications; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Fibrin; Fibrinogen; Half-Life; Humans; Iodine Radioisotopes; Middle Aged