Coagulation and fibrinolytic system impairment in insulin dependent diabetes mellitus

Long term clinical follow up of four patients with Wolfram syndrome and urodynamic abnormalities

OBJECTIVES

Wolfram syndrome is characterised by insulin-dependent diabetes (IDDM), diabetes insipidus (DI), optic atrophy, sensorineural deafness and neurocognitive disorders. The DIDMOAD acronym has been recently modified to DIDMOAUD suggesting the rising awareness of the prevalence of urinary tract dysfunction (UD). End stage renal disease is the commonest cause of mortality in Wolfram syndrome. We present a case series with main objective of long term follow up in four children having Wolfram syndrome with evaluation of their urodynamic profile.

METHODS

A prospective follow up of four genetically proven children with Wolfram syndrome presenting to a tertiary care pediatric diabetes clinic in Pune, India was conducted. Their clinical, and urodynamic parameters were reviewed.

RESULTS

IDDM, in the first decade, was the initial presentation in all the four children (three male and one female). Three children had persistent polyuria and polydipsia despite having optimum glycemic control; hence were diagnosed to have DI and treated with desmopressin. All four patients entered spontaneous puberty. All patients had homozygous mutation in WFS1 gene; three with exon 8 and one with exon 6 novel mutations. These children with symptoms of lower urinary tract malfunction were further evaluated with urodynamic studies; two of them had hypocontractile detrusor and another had sphincter-detrusor dyssynergia. Patients with hypocontractile bladder were taught clean intermittent catheterization and the use of overnight drain.

CONCLUSIONS

We report a novel homozygous deletion in exon 6 of WFS-1 gene. The importance of evaluation of lower urinary tract malfunction is highlighted by our case series. The final bladder outcome in our cases was a poorly contractile bladder in three patients.

Mechanisms of endothelial activation, hypercoagulation and thrombosis in COVID-19: a link with diabetes mellitus

Early since the onset of the COVID-19 pandemic, the medical and scientific community were aware of extra respiratory actions of SARS-CoV-2 infection. Endothelitis, hypercoagulation, and hypofibrinolysis were identified in COVID-19 patients as subsequent responses of endothelial dysfunction. Activation of the endothelial barrier may increase the severity of the disease and contribute to long-COVID syndrome and post-COVID sequelae. Besides, it may cause alterations in primary, secondary, and tertiary hemostasis. Importantly, these responses have been highly decisive in the evolution of infected patients also diagnosed with diabetes mellitus (DM), who showed previous endothelial dysfunction. In this review, we provide an overview of the potential triggers of endothelial activation related to COVID-19 and COVID-19 under diabetic milieu. Several mechanisms are induced by both the viral particle itself and by the subsequent immune-defensive response (i.e., NF-κB/NLRP3 inflammasome pathway, vasoactive peptides, cytokine storm, NETosis, activation of the complement system). Alterations in coagulation mediators such as factor VIII, fibrin, tissue factor, the von Willebrand factor: ADAMST-13 ratio, and the kallikrein-kinin or plasminogen-plasmin systems have been reported. Moreover, an imbalance of thrombotic and thrombolytic (tPA, PAI-I, fibrinogen) factors favors hypercoagulation and hypofibrinolysis. In the context of DM, these mechanisms can be exacerbated leading to higher loss of hemostasis. However, a series of therapeutic strategies targeting the activated endothelium such as specific antibodies or inhibitors against thrombin, key cytokines, factor X, complement system, the kallikrein-kinin system or NETosis, might represent new opportunities to address this hypercoagulable state present in COVID-19 and DM. Antidiabetics may also ameliorate endothelial dysfunction, inflammation, and platelet aggregation. By improving the microvascular pathology in COVID-19 and post-COVID subjects, the associated comorbidities and the risk of mortality could be reduced.

Inflammatory protein signatures in individuals with obesity and metabolic syndrome

There is variability in the metabolic health status among individuals presenting with obesity; some may be metabolically healthy, while others may have developed the metabolic syndrome, a cluster including insulin resistance, hypertension, dyslipidemia, and increased risk of cardiovascular disease and type 2 diabetes. The mechanisms contributing to this metabolic heterogeneity are not fully understood. To address this question, plasma samples from 48 individuals with BMI ≥ 35 kg/m2 were examined (27 with and 21 without metabolic syndrome). Fasting plasma samples were subjected to Olink proteomics analysis for 184 cardiometabolic and inflammation-enriched proteins. Data analysis showed a clear differentiation between the two groups with distinct plasma protein expression profiles. Twenty-four proteins were differentially expressed (DEPs) between the two groups. Pathways related to immune cell migration, leukocyte chemotaxis, chemokine signaling, mucosal inflammatory response, tissue repair and remodeling were enriched in the group with metabolic syndrome. Functional analysis of DEPs revealed upregulation of 15 immunological pathways. The study identifies some of the pathways that are altered and reflect metabolic health in individuals with obesity. This provides valuable insights into some of the underlying mechanisms and can lead to identification of therapeutic targets to improve metabolic health in individuals with obesity.

Heterogeneity of outcomes within diabetic patients with atrial fibrillation on edoxaban: a sub-analysis from the ETNA-AF Europe registry

BACKGROUND

Recent data have suggested that insulin-requiring diabetes mostly contributes to the overall increase of thromboembolic risk in patients with atrial fibrillation (AF) on warfarin. We evaluated the prognostic role of a different diabetes status on clinical outcome in a large cohort of AF patients treated with edoxaban.

METHODS

We accessed individual patients' data from the prospective, multicenter, ETNA-AF Europe Registry. We compared the rates of ischemic stroke/transient ischemic attack (TIA)/systemic embolism, myocardial infarction (MI), major bleeding and all-cause death at 2 years according to diabetes status.

RESULTS

Out of an overall population of 13,133 patients, 2885 had diabetes (22.0%), 605 of whom (21.0%) were on insulin. The yearly incidence of ischemic stroke/TIA/systemic embolism was 0.86% in patients without diabetes, 0.87% in diabetic patients not receiving insulin (p = 0.92 vs no diabetes) and 1.81% in those on insulin (p = 0.002 vs no diabetes; p = 0.014 vs diabetes not on insulin). The annual rates of MI and major bleeding were 0.40%, 0.43%, 1.04% and 0.90%, 1.10% and 1.71%, respectively. All-cause yearly mortality was 3.36%, 5.02% and 8.91%. At multivariate analysis, diabetes on insulin was associated with a higher rate of ischemic stroke/TIA/systemic embolism [adjusted HR 2.20, 95% CI 1.37-3.54, p = 0.0011 vs no diabetes + diabetes not on insulin] and all-cause death [aHR 2.13 (95% CI 1.68-2.68, p < 0.0001 vs no diabetes]. Diabetic patients not on insulin had a higher mortality [aHR 1.32 (1.11-1.57), p = 0.0015], but similar incidence of stroke/TIA/systemic embolism, MI and major bleeding, vs those without diabetes.

CONCLUSIONS

In a real-world cohort of AF patients on edoxaban, diabetes requiring insulin therapy, rather than the presence of diabetes per se, appears to be an independent factor affecting the occurrence of thromboembolic events during follow-up. Regardless of the diabetes type, diabetic patients had a lower survival compared with those without diabetes.

Procoagulant factors and future risk of arterial cardiovascular disease in patients with prior venous thrombosis: A cohort study

Patients with venous thrombosis (VT) are at increased risk of future arterial cardiovascular disease (CVD) (i.e., myocardial infarction, ischemic stroke or peripheral artery disease). We investigated whether shared risk factors for VT and CVD are associated with the levels of procoagulant factors (fibrinogen, factor VIII, and von Willebrand factor), and whether the relationship between these risk factors and subsequent CVD was mediated through these procoagulant factors in patients with VT. In a follow-up study consisting of 4956 patients with VT, 2176 patients (44%) provided blood samples and were linked to the Dutch Hospital registry of Statistics Netherlands to identify hospital admissions or procedures for subsequent CVD. In total, 52 CVD events occurred over a follow-up of 11,124 years, with an incidence rate of 4.7 per 1000 patient years (95% confidence intervals 3.5-6.1). Increasing age, male sex, smoking history, major illnesses, dyslipidemia, and impaired fasting glucose levels were associated with increased CVD risk. Procoagulant factor levels were also associated with CVD risk. When adjusted for these procoagulant factors, the association between the risk factors and CVD attenuated partially. This study provides evidence that procoagulant factors can partially explain the association between increased risks of subsequent CVD in patients with previous VT.

Antidepressants and the risk of myocardial infarction among patients with diabetes: A population-based cohort study

OBJECTIVE

To investigate the impact of antidepressants (ATDs) on the risk of myocardial infarction (MI) among patients with diabetes mellitus (DM).

METHODS

This was a retrospective population-based cohort study that used data obtained from the National Health Insurance Research Database in Taiwan. The study cohort included diabetic patients who were older than 50 years from 1997 to 2010. We then randomly assigned individuals to the matched cohort at a 1:1 ratio according to their demographic data. Both study and matched cohorts were followed up to compare the risk of MI between patients with and without ATD use from 2000 until the end of 2013. Multivariate Cox proportional hazards models were used to evaluate the relationship between ATD treatment and the occurrence of MI.

RESULTS

After adjustment for confounders, patients with ATD use of more than 180 days had a lower risk of MI than those without ATD use in the matched cohort (adjusted hazard ratio [HR] = 0.68, 95% confidence interval [CI], 0.66-0.71). The adjusted HRs of MI were 0.77 (95% CI, 0.73-0.81) and 0.56 (95% CI, 052.-0.60) in patients with DM and ATD use of 180 > cDDD ≥ 28 and cDDD ≥ 180, respectively. When the duration of ATD treatment was 180 days or longer, MI risk was significantly reduced (after adjustment) for all classes of ATD except bupropion.

CONCLUSIONS

Most ATDs, but not bupropion, were associated with significantly reduced risk of MI among the DM population.

Hemostatic state of children with type 1 diabetes

PURPOSE

Hyperglycemia is one of the factors responsible for the molecular alterations that modify hemostasis. The aim of this study was to determine the levels of circulating molecules that have a prothrombotic impact on the child and adolescent population with type 1 diabetes mellitus.

METHODS

There were 35 patients with type 1 diabetes mellitus (11.0±2.5 years of age and a median 3.7±2.0 years of the disease) with no vascular complications and 20 healthy controls with similar age, sex, and body mass index included in the study. The evaluated parameters were fibrinogen, plasminogen activator inhibitor-1 (PAI1), von Willebrand factor antigen, and standard coagulation tests (platelet count, prothrombin time, and activated partial thromboplastin time). Glycemic control was evaluated by hemoglobin A1c and fasting blood glucose tests, and the presence of retinopathy and nephropathy was ruled out. The data obtained were analyzed by IBM SPSS Statistics ver. 20.0 and expressed as mean±standard deviation. The Pearson correlation coefficient was applied to investigate correlations between variables.

RESULTS

Diabetic patients showed significantly higher levels of fibrinogen (308±66 mg/dL vs. 246±18 mg/dL, P=0.0001), PAI-1 (41.6±12 ng/mL vs. 11.7±1.0 ng/mL, P=0.0001), and von Willebrand factor antigen (284%±55% vs. 121%±19%, P=0.0001). However, standard coagulation tests did not show differences between the 2 groups. PAI-1 was correlated with glycemia, hemoglobin A1c, fibrinogen, and von Willebrand factor antigen.

CONCLUSION

Elevated levels of fibrinogen, PAI-1, and von Willebrand factor antigen were found in the pediatric and adolescent population with type 1 diabetes mellitus, which suggests a prothrombotic state.

Increased tissue factor activity promotes thrombin generation at type 1 diabetes onset in children

OBJECTIVE

In type 1 diabetes (T1D), a prothrombotic status due to elevated coagulation factors coincides with metabolic derailment. In a previous study, we discovered altered thrombin generation profiles in children with T1D. These alterations are potentially most pronounced at T1D onset and ameliorated after insulin treatment. We tested this hypothesis in a longitudinal study, measuring thrombin generation together with coagulation parameters in children at T1D onset and during follow-up.

MATERIALS AND METHODS

Twenty-three children (12 female, age: 9.4 [2.7-17.3] years; median [range]) were tested at T1D onset and after long-term insulin treatment. Thrombin generation was measured using calibrated automated thrombography. Tissue factor (TF) activity and tissue factor pathway inhibitor (TFPI) activity were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

A procoagulant shift was observed in thrombin generation traces at T1D onset compared to follow-up (time to peak: 5.67 [4.11-7.67] min vs 6.39 [4.89-10.44] min, P < .001). These alterations at T1D onset coincided with increased TF activity (5.18 [0.01-12.97] pmol/L vs 2.67 [0.04-10.41] pmol/L, P < .05) and increased TFPI activity (0.051 [0.038-0.074] U/mL vs 0.035 [0.026-0.056] U/mL, P < .05).

CONCLUSION

The procoagulant shift in thrombin generation at T1D onset is a result of increased TF activity, but this effect is partially counterbalanced by increased TFPI levels. Elevated TF and TFPI levels hint to a fragile hemostatic balance at the endothelial lining of blood vessels. Additional prothrombotic stimuli may tip over this balance explaining the increased thrombotic risk of children with T1D.

Clinical Outcome of Edoxaban vs. Vitamin K Antagonists in Patients with Atrial Fibrillation and Diabetes Mellitus: Results from a Multicenter, Propensity-Matched, Real-World Cohort Study

Diabetes mellitus (DM) is a chronic metabolic disease which is independently associated with unfavorable clinical outcomes in patients with atrial fibrillation (AF). Few real-world data are available about the clinical performance of non-vitamin K oral anticoagulants (NOACs) among patients with atrial fibrillation and diabetes. The aim of our propensity score-matched cohort study was to compare the safety and effectiveness of Edoxaban versus well-controlled vitamin K antagonists (VKAs) therapy among this population. In this study, we considered patients with AF and diabetes on Edoxaban or VKAs therapy included in the multicenter Atrial Fibrillation Research Database (NCT03760874). The occurrence of major bleedings (MB) and thromboembolic events (a composite of ischemic stroke, transient ischemic attack, systemic embolism) was respectively considered primary safety and effectiveness outcome. We identified 557 AF patients with diabetes who received Edoxaban (n: 230) or VKAs (n: 327) treatment. After propensity score matching analysis, 135 Edoxaban and 135 VKA recipients with similar clinical characteristics were evaluated. The mean follow-up was 27 ± 3 months. The incidence rate of thromboembolic events (TE) was 3.0 per 100 person-years (1.11 in Edoxaban vs. 1.9 in the VKA group, hazard ratio (HR): 0.59; 95% confidence interval (CI), 0.14 to 2.52; p = 0.48). The incidence rate of major bleedings (MB) was 3.7 per 100 person-years (1.2 in Edoxaban vs. 2.7 in the VKA group, HR: 0.43; 95% CI: 0.10 to 1.40; p = 0.14). The incidence rate of intracranial hemorrhage was 0.35 per 100 person-years in Edoxaban vs. 0.74 in the VKA group (HR: 0.49; 95% CI: 0.05 to 5.54; p = 0.56). A positive net clinical benefit (NCB) of Edoxaban over VKAs was found (+1.39). Insulin therapy (HR: 1.76, p = 0.004) and glycated hemoglobin (HR: 1.17, p = 0.002) were found to be independent predictors of TE; moreover, the concomitant use of antiplatelet drugs (HR: 2.41, p = 0.001) was an independent predictor of MB. Conclusions: Our data support the hypothesis of the safety and efficacy of Edoxaban for use in patients with AF and diabetes, justified by a favorable NCB over VKAs.

Endothelial Dysfunction, Fibrinolytic Activity, and Coagulation Activity in Patients With Atrial Fibrillation According to Type II Diabetes Mellitus Status

Recent findings in atrial fibrillation (AF) patients receiving oral anticoagulation showed that diabetes without insulin therapy has a thromboembolic risk comparable to nondiabetic patients, whereas only diabetic patients on insulin have a heightened thromboembolic risk. We explored possible pathophysiological correlates of such finding on 90 AF patients on oral anticoagulation, divided according to diabetes status (n = 30 without diabetes; n = 29 with diabetes on oral antidiabetic drugs; n = 31 with insulin-requiring diabetes). We assessed von Willebrand Factor (VWF) concentration (VWF:Ag) and activity (VWF R:Co) as measures of endothelial dysfunction; and thrombin-activatable fibrinolysis inhibitor (TAFI) and prothrombin fragment 1 + 2 (F1+2) levels as markers of fibrinolytic activity and thrombin generation. Values of VWF:Ag, VWF:RCo, and TAFI were similar in the 3 groups. Patients with diabetes requiring insulin had significantly higher levels of F1+2 (median 23.1 pg/ml [interquartile range 17.6; 33.5]) than those without diabetes (16.3 pg/ml [11.5; 22.5], p = 0.036) and diabetic patients on oral antidiabetic drugs (20.6 pg/ml [13.3; 29], p = 0.046). Thus, in AF patients receiving oral anticoagulation, those with diabetes, regardless of the diabetes type (with or without insulin therapy), and those without diabetes have comparable indices of the explored parameters of endothelial dysfunction and fibrinolytic activity. Despite anticoagulant therapy, thrombin generation is selectively higher in diabetic patients' on insulin than in those without diabetes or with diabetes on oral antidiabetic drugs, with no differences between these latter 2 conditions. Thrombin generation might thus be a predominant contributor to the excess of thromboembolic risk in AF patients on insulin-requiring diabetes.

Elevated HbA1c is not associated with recurrent venous thromboembolism in the elderly, but with all-cause mortality- the SWEETCO 65+ study

The association of glycated hemoglobin (HbA1c) with venous thromboembolism (VTE) and death in the elderly is unknown. In the SWEETCO 65+ study we analyzed prospectively a Swiss Cohort of Elderly Patients with Venous Thromboembolism (SWITCO 65+). 888 patients were enrolled for the SWEETCO 65+ analysis. HbA1c was determined at baseline and divided into three categories (HbA1c < 5.7%, normal range; 5.7–6.49%, pre-diabetic range; and >6.5%, diabetic range). Median follow-up was 2.5 years. The primary endpoint was recurrent VTE. Secondary endpoints included all-cause mortality and major bleeds. The total prevalence of diabetes was 22.1%. The risk of recurrent VTE was similar in patients with HbA1c with pre-diabetes (adjusted subhazard ratio (aSHR) 1.07 [0.70 to 1.63]) and diabetes (aSHR 0.73 [0.39 to 1.37]) as compared to those with a HbA1c in the normal range. However, a HbA1c ≥ 6.5% (median IQ range 7.0 [6.70;7.60]) was significantly associated with a higher risk of all-cause mortality (adjusted hazard ratio [aHR] 1.83 [1.21 to 2.75]). In summary we found no association between HbA1c and major bleeding. Elevated HbA1c levels are not associated with recurrent VTE but with increased all-cause mortality in an elderly population with acute VTE.

Antidepressants Reduced Risk of Mortality in Patients With Diabetes Mellitus: A Population-Based Cohort Study in Taiwan

CONTEXT

The effect of antidepressant (ATD) use on mortality in patients with diabetes mellitus (DM) has not yet been sufficiently studied, although comorbid depression is common in this population.

OBJECTIVE

To explore the impact of ATDs on mortality among DM patients.

DESIGN

A retrospective cohort study in a national database.

SETTING

This population-based study used the National Health Insurance Research Database in Taiwan. Since 2000, we identified 53,412 cases of newly diagnosed patients with DM and depression. Patient cases were followed for assessing mortality until 2013.

MAIN OUTCOME MEASURE

The association between mortality and ATD use was explored adjusting for cumulative dosing.

RESULTS

Using the time-dependent Cox regression model, ATD use was associated with significantly reduced mortality among patients with DM [in the highest dose group: hazard ratio (HR), 0.65; 95% CI, 0.59 to 0.71]. Further analysis showed that differences in mortality existed across ATD categories: selective serotonin reuptake inhibitors (HR, 0.63; 95% CI, 0.56 to 0.71), serotonin-norepinephrine reuptake inhibitors (HR, 0.58; 95% CI, 0.44 to 0.78), norepinephrine-dopamine reuptake inhibitors (HR, 0.20; 95% CI, 0.07 to 0.63), mirtazapine (HR, 0.60; 95% CI, 0.45 to 0.82), tricyclic/tetracyclic antidepressants (HR, 0.73; 95% CI, 0.54 to 0.97), and trazodone (HR, 0.52; 95% CI, 0.29 to 0.91). However, reversible inhibitor of monoamine oxidase A (RIMA) was found to be associated with an increase, rather than a decrease, in total mortality (HR, 1.48; 95% CI, 1.09 to 1.99).

CONCLUSION

Most ATDs, but not RIMA, were associated with significantly reduced mortality among a population with comorbid DM and depression.

Role of diabetes and insulin use in the risk of stroke and acute myocardial infarction in patients with atrial fibrillation: A Medicare analysis

BACKGROUND

Atrial fibrillation (AF) is associated with elevated risk for ischemic stroke and myocardial infarction (MI). The aim of the study is to assess the role of insulin use on the risk of stroke and MI in AF patients with diabetes.

METHODS

We identified Medicare beneficiaries with new AF in 2011 to 2013. Primary outcomes were ischemic stroke and MI. Multivariate Cox regression models were used to assess the association between AF and time to stroke and MI. We adjusted for anticoagulant as a time-dependent covariate.

RESULTS

Out of 798,592 AF patients, 53,212 (6.7%) were insulin-requiring diabetics (IRD), 250,214 (31.3%) were non-insulin requiring diabetics (NIRD) and 495,166 (62%) were non-diabetics (ND). IRD had a higher risk of stroke when compared to NIRD (adjusted HR: 1.15, 95% CI 1.10-1.21) and ND (aHR 1.24, 95% CI 1.18-1.31) (P < .01 for both). The risk of stroke was higher in NIRD compared to ND (aHR 1.08, 95% CI 1.05-1.12). For the outcome of MI, IRD had a higher risk compared to NIRD (aHR 1.24, 95% CI 1.18-1.31) and ND (aHR 1.46, 95% CI 1.38-1.54)]. NIRD had a higher risk compared to ND (aHR 1.17, 95% CI 1.13-1.22). Anticoagulation were most effective at preventing stroke in ND [0.72 (0.69-0.75)], and NIRD [0.88 (0.85-0.92)], but were not associated with significant reduction in stroke in IRD [0.96 (0.89-1.04)].

CONCLUSION

There is an incremental risk of ischemic stroke and MI from non-diabetics to non-insulin diabetics with the highest risk in insulin users. Protective effect of anticoagulation is attenuated with insulin use.

The biophysics and mechanics of blood from a materials perspective

Cells actively interact with their microenvironment, constantly sensing and modulating biochemical and biophysical signals. Blood comprises a variety of non-adherent cells that interact with each other and with endothelial and vascular smooth muscle cells of the blood vessel walls. Blood cells are further experiencing a range of external forces by the hemodynamic environment and they also exert forces to remodel their local environment. Therefore, the biophysics and material properties of blood cells and blood play an important role in determining blood behaviour in health and disease. In this Review, we discuss blood cells and tissues from a materials perspective, considering the mechanical properties and biophysics of individual blood cells and endothelial cells as well as blood cell collectives. We highlight how blood vessels provide a mechanosensitive barrier between blood and tissues and how changes in vessel stiffness and flow shear stress can be correlated to plaque formation and exploited for the design of vascular grafts. We discuss the effect of the properties of fibrin on blood clotting, and investigate how forces exerted by platelets are correlated to disease. Finally, we hypothesize that blood and vascular cells are constantly establishing a mechanical homeostasis, which, when imbalanced, can lead to hematologic and vascular diseases.

Association of coagulation profile with microvascular complications and glycemic control in type 2 diabetes mellitus - a study at a tertiary care center in Delhi

Introduction

Type 2 diabetes mellitus, characterized by insulin resistance, corresponds to approximately 90% of cases of diabetes worldwide. Hyperglycemia in diabetes contributes to hyperfibrinogenemia and activates the coagulation cascade thereby producing atherothrombotic events.

Objectives

This study was designed to evaluate the coagulation profile (activated partial thromboplastin time, prothrombin time and fibrinogen) in Type 2 diabetes and to analyze correlations between body mass index, fasting blood glucose, glycated hemoglobin and duration of diabetes with coagulation parameters.

Methods

This study included 60 type 2 diabetics and 30 controls. Diabetic patients were grouped in two sets based on the presence or absence of microvascular complications. The demographic profile and clinical details were recorded. Fasting blood glucose, glycated hemoglobin, coagulation parameters such as prothrombin time, activated partial thromboplastin time and fibrinogen along with other biochemical parameters were investigated.

Results

There were statistically significant differences in the coagulation parameters between the two groups of diabetics (with and without complications). The present study also found significant correlations between age and the duration of diabetes with and without complications and coagulation parameters such as the activated partial thromboplastin time, which was found to be significantly lower, and fibrinogen, which was found to be significantly higher in subjects with complications compared to subjects without complications.

Conclusion

Clinical tests for prothrombin time, activated partial thromboplastin time and fibrinogen are relatively inexpensive and readily available. The present study shows that shortened prothrombin time, activated partial thromboplastin time and increased fibrinogen levels might be useful hemostatic markers in diabetic patients, especially in those at high-risk for thrombotic complications.

Evaluation of Coagulation Profile in Children with Type 1 Diabetes Mellitus Using Rotational Thromboelastometry

The prothrombotic state in type 1 diabetes mellitus (T1DM) has been reported as a plausible cause of vascular complications. Rotational thromboelastometry (ROTEM) assay enables the global assessment of coagulation status. This study aimed to assess hypercoagulability in children with T1DM using ROTEM. A total of 43 T1DM children (20 females and 23 males) aged 2-18 years and age- and sex-matched 30 healthy control subjects were enrolled in the study group. ROTEM assays [intrinsic TEM (INTEM) and extrinsic TEM (EXTEM)] were used to measure and analyze coagulation time (CT), clot formation time, maximum clot firmness (MCF). Glycated hemoglobin levels (HbA1c), diabetic complications, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and dimerized plasmin fragment D (D-dimer) were determined in the study group. The mean duration of T1DM diagnosis was 3.15 ± 2.49 years, and the mean HbA1c level was 8.94 ± 1.88% (74.29 ± 20.59 mmol/mol). None of the patients had macrovascular complications. Nephropathy was present in five patients. In the T1DM group, EXTEM-CT [80.00 (66.75-108.50)] was significantly lower, and EXTEM-MCF [65.00 (64.00-70.00)] and INTEM-MCF [65.00 (62.00-68.00)] were significantly higher than in the controls (p < 0.001, p = 0.026, and p = 0.004, respectively). However, the duration of T1DM and the degree of metabolic control had no influence on these parameters. Platelet count, PT, aPTT, fibrinogen and D-dimer levels were comparable between the diabetic patients and the control group. There were statistically significant correlations between fibrinogen level and INTEM-MCF and EXTEM-MCF (p < 0.001, p = 0.002 and r = 0.545, r = 0.454, respectively) This study shows that decreased levels of CT and increased levels of MCF suggest hypercoagulability in patients with T1DM. Further studies are needed to confirm our findings on a larger number of diabetic patients.

Glucose and angiotensin II-derived endothelial extracellular vesicles regulate endothelial dysfunction via ERK1/2 activation

In various diseases, including diabetes, extracellular vesicles (EVs) have been detected in circulation and tissues. EVs are small membrane vesicles released from various cell types under varying conditions. Recently, endothelial cell-derived EVs (EEVs) were identified as a marker of endothelial dysfunction in diabetes, but the ensuing mechanisms remain poorly understood. In this study, we dissected the ensuing pathways with respect to nitric oxide (NO) production under the condition of type 2 diabetes. Human umbilical vein endothelial cells (HUVECs) were stimulated with glucose alone and with glucose in combination with angiotensin II (Ang II) for 48 h. In supernatants from glucose + Ang II-stimulated HUVECs, release of EEVs was assessed using Western blotting with an anti-CD144 antibody. EEV release was significantly increased after stimulation of HUVECs, and high glucose + Ang II-derived EEVs impaired ACh-induced vascular relaxation responses and NO production in mice aortic rings. Furthermore, high glucose + Ang II-derived EEVs induced ERK1/2 signalling and decreased endothelial NO synthase (eNOS) protein expression in mice aortas. Furthermore, in the presence of the MEK/ERK1/2 inhibitor PD98059, high glucose plus Ang II treatment stimulated EEVs in HUVECs and those EEVs prevented the impairments of ACh-induced relaxation and NO production in mice aortas. These data strongly indicate that high glucose and Ang II directly affect endothelial cells and the production of EEVs; the resultant EEVs aggravate endothelial dysfunction by regulating eNOS protein levels and ERK1/2 signalling in mice aortas.

Outcomes Following Advanced Wound Care for Diabetic Foot Ulcers: A Canadian Study

OBJECTIVES

Data concerning outcomes of Canadian patients with diabetic foot ulcers (DFUs) are limited. The objectives of this study were to evaluate the healing rates and identify the predictors of poor outcomes following advanced wound care in patients presenting with DFUs.

METHODS

We conducted retrospective cohort study of adult patients who had DFUs and were referred to a single Canadian advanced diabetic foot and wound care centre between January 1, 2010, and December 31, 2010. The primary outcome was the healing rate at 52 weeks. The generalized estimating equation model was used to identify potential risk factors associated with delayed healing of DFUs.

RESULTS

Of the 40 patients for whom there were complete follow ups, 35 (87.5%) had healing of all DFUs by 52 weeks. Predictors of poor healing were the presence of chronic ulcers, ulcer sizes >1 cm², peripheral vascular disease and multiple ulcers at first presentation. Of the patients, 7.1% required amputation, and 8.9% of patients receiving our treatment died before 52 weeks. At 52 weeks of follow up, 16 of 17 recurrent ulcers and 68 of 108 pre-existing ulcers had healed. Compared to the unadjusted healing rate of preexisting ulcers (63.0%), the unadjusted healing rate of recurrent ulcers (94.1%) was significantly higher (p=0.01).

CONCLUSIONS

Our findings demonstrate that patients with DFUs in Canada who receive early and continued care from specialized, outpatient, advanced wound care centres experience significantly improved rates of healing of recurrent DFUs compared to pre-existing DFUs.

In Vivo Functional Evaluation of Tissue-Engineered Vascular Grafts Fabricated Using Human Adipose-Derived Stem Cells from High Cardiovascular Risk Populations

Many preclinical evaluations of autologous small-diameter tissue-engineered vascular grafts (TEVGs) utilize cells from healthy humans or animals. However, these models hold minimal relevance for clinical translation, as the main targeted demographic is patients at high cardiovascular risk such as individuals with diabetes mellitus or the elderly. Stem cells such as adipose-derived mesenchymal stem cells (AD-MSCs) represent a clinically ideal cell type for TEVGs, as these can be easily and plentifully harvested and offer regenerative potential. To understand whether AD-MSCs sourced from diabetic and elderly donors are as effective as those from young nondiabetics (i.e., healthy) in the context of TEVG therapy, we implanted TEVGs constructed with human AD-MSCs from each donor type as an aortic interposition graft in a rat model. The key failure mechanism observed was thrombosis, and this was most prevalent in grafts using cells from diabetic patients. The remainder of the TEVGs was able to generate robust vascular-like tissue consisting of smooth muscle cells, endothelial cells, collagen, and elastin. We further investigated a potential mechanism for the thrombotic failure of AD-MSCs from diabetic donors; we found that these cells have a diminished potential to promote fibrinolysis compared to those from healthy donors. Together, this study served as proof of concept for the development of a TEVG based on human AD-MSCs, illustrated the importance of testing cells from realistic patient populations, and highlighted one possible mechanistic explanation as to the observed thrombotic failure of our diabetic AD-MSC-based TEVGs.

Hepatitis C Virus Infection Associated With an Increased Risk of Deep Vein Thrombosis: A Population-Based Cohort Study

The association between the hepatitis C virus (HCV) infection and the risk of myocardial infarction (MI) and stroke has been previously investigated. However, the association between the HCV infection and the risk of venous thromboembolism (VTE) has not been extensively discussed. Using the Longitudinal Health Insurance Database 2000 (LHID2000), we selected 3686 patients with newly diagnosed HCV infection. We randomly selected 14,744 people with no HCV or hepatitis B virus (HBV) infection as comparison group and frequency matched them with patients with HCV infection according to their age, sex, and index year. The incidence density rates and hazard ratios (HRs) of deep vein thrombosis (DVT) and pulmonary embolism (PE) were calculated until the end of 2011. The mean follow-up duration of 5.14 years for the HCV cohort and 5.61 years for the non-HCV cohort, the overall incidence density rates of DVT were 7.92 and 3.51 per 10,000 person-years in the non-HCV group, and the HCV groups, respectively (crude HR = 2.25; 95% confidence interval [CI] = 1.21-4.21). After adjusted for age, sex, and comorbidities, the risk of DVT remained significantly higher in the HCV group than in the non-HCV group (adjusted HR = 1.96; 95% CI = 1.03-3.73). The overall incidence density rates of PE in the HCV and non-HCV groups were not significantly different (crude HR = 2.20; 95% CI = 0.94-5.14). HCV infection is associated with the risk of DVT in a long-term follow-up period.

Peripheral artery disease in patients with diabetes: Epidemiology, mechanisms, and outcomes

Peripheral artery disease (PAD) is the atherosclerosis of lower extremity arteries and is also associated with atherothrombosis of other vascular beds, including the cardiovascular and cerebrovascular systems. The presence of diabetes mellitus greatly increases the risk of PAD, as well as accelerates its course, making these patients more susceptible to ischemic events and impaired functional status compared to patients without diabetes. To minimize these cardiovascular risks it is critical to understand the pathophysiology of atherosclerosis in diabetic patients. This, in turn, can offer insights into the therapeutic avenues available for these patients. This article provides an overview of the epidemiology of PAD in diabetic patients, followed by an analysis of the mechanisms by which altered metabolism in diabetes promotes atherosclerosis and plaque instability. Outcomes of PAD in diabetic patients are also discussed, with a focus on diabetic ulcers and critical limb ischemia.

Tissue factor and Toll-like receptor (TLR)4 in hyperglycaemia-hyperinsulinaemia. Effects in healthy subjects, and type 1 and type 2 diabetes mellitus

Diabetes mellitus (DM) patients have an increased incidence of cardiovascular events. Blood tissue factor-procoagulant activity (TF-PCA), the initiating mechanism for blood coagulation, is elevated in DM. We have shown that hyperglycaemia (HG), hyperinsulinaemia (HI) and combined HG+HI (induced using 24-hour infusion clamps) increases TF-PCA in healthy and type 2 DM (T2DM) subjects, but not in type 1 DM (T1DM) subjects. The mechanisms for this are unknown. DM patients have elevated plasma lipopolysaccharide (LPS), a toll-like receptor (TLR) 4 ligand. We postulated that TLR4 plays a role in modulating TF levels. We studied the effect of HG+HI on TLR4 and TF-PCA in vivo during 24-hour HG+HI infusion clamps in healthy subjects, and T1DM and T2DM subjects, and in vitro in blood. In vivo, in healthy subjects, 24-hour HG + HI infusion increased TLR4 six-fold, which correlated with TF-PCA (r= 0.91, p<0.0001). T2DM patients showed smaller increases in both. In T1DM subjects, TLR4 declined (50%, p<0.05) and correlated with TF-PCA (r=0.55; p<0.05). In vitro, HG (200 mg/dl added glucose) and HI (1-100 nM added insulin) increased TF-PCA in healthy subjects (~2-fold, 2-4 hours). Insulin inhibited by ~30% LPS-induced increase in TF-PCA and high glucose reversed it. TLR4 levels paralleled TF-PCA (r=0.71, p<0.0001); HG and HI increased TLR4 and insulin inhibited LPS-induced TLR4 increase. This is first evidence that even in healthy subjects, HG of short duration increases TLR4 and TF-PCA, key players in inflammation and thrombosis. TLR4-TF interplay is strikingly different in non-diabetic, T1DM and T2DM subjects.

Diabetes is associated with increased risk of venous thromboembolism: a systematic review and meta-analysis

AIMS

Increasing evidence suggests an association between diabetes and risk of venous thromboembolism (VTE); however, the results are inconsistent. We conducted a systematic review and meta-analysis of all epidemiological evidence to clarify association of diabetes with risk of VTE.

METHODS

We searched MEDLINE and EMBASE to retrieve all relevant articles. Pooled effect estimates were calculated through a random-effects model.

RESULTS

Sixteen articles involving 803,627,121 participants and 10,429,227 VTE patients were included. Pooled analysis of all evidence suggested that diabetes was associated with increased risk of VTE (HR, 1.35; 95%CI, 1.17-1.55; p=2.92*10(-5)), with evidence of small-study effect (p=0.024) and heterogeneity (I(2)=87.1%, p<0.001). However, when analysis was restricted to high quality cohort studies, the association remained significantly (HR, 1.36; 95%CI 1.11-1.68; p=0.004), with no evidence of publication bias (p=0.192) and heterogeneity (I(2)=23.2%, p=0.245).

CONCLUSIONS

Diabetes is associated with increased risk of VTE, which may have implications for the primary and secondary prevention of VTE.

Diabetes mellitus does not increase the risk of adverse long-term outcomes after intracranial stent placement

The present study is to investigate whether diabetes mellitus (DM) increases risk of adverse long-term outcomes after intracranial stent placement. Patients receiving intracranial stenting were assigned to DM group and non-DM group according to diabetes status. The long-term follow-up endpoint was composite of any stroke and death within 30 days, any ischemic stroke beyond 30 days, and transient ischemic attack in the territory of the stented artery at any time. A total of 44 stenoses in 43 patients were retrospectively analyzed. The cumulative probability of the composite outcomes were 15.4% (95% CI 15.3-47.3%) at 1 year and 30.8% (95% CI 26.5-33.6%) at 2 years for DM group; 17.5% (95% CI 16.0-31.2%) at both 1 year and 2 years for non-DM group (log-rank test, P = 0.424). After adjusting for the confounders, the risk of DM versus non-DM for composite outcomes remained insignificant (hazard ratio: 2.84, 95% CI 0.46-17.66; P = 0.26). Our results showed that there is no significant difference between patients with DM and without DM in cumulative probability of the composite outcomes. It suggests that based on our data, there is no evidence that DM increases the risk of adverse long-term outcomes after intracranial stent placement.

Whole-blood tissue factor procoagulant activity is elevated in type 1 diabetes: effects of hyperglycemia and hyperinsulinemia

OBJECTIVE

To determine tissue factor procoagulant activity (TF-PCA) in patients with type 1 diabetes and to examine effects of hyperglycemia and hyperglycemia plus hyperinsulinemia on TF-PCA.

RESEARCH DESIGN AND METHODS

We have determined circulating TF-PCA and other coagulation factors under basal (hyperglycemic) conditions, after acute correction of hyperglycemia, in response to 24 h of selective hyperglycemia, and in response to 24 h of hyperglycemia plus hyperinsulinemia in nine type 1 diabetic patients and in seven nondiabetic control subjects.

RESULTS

As shown previously in patients with type 2 diabetes, basal TF-PCA and plasma coagulation factor VIIa (FVIIa) were higher in patients with type 1 diabetes than in nondiabetic control subjects. However, in contrast with type 2 diabetes, normalizing glucose did not decrease the elevated TF-PCA levels, and raising glucose or glucose plus insulin levels did not increase TF-PCA.

CONCLUSIONS

Patients with type 1 diabetes have elevated circulating TF-PCA and FVIIa levels and are in a procoagulant state that may predispose them to acute cardiovascular events. The mechanisms regulating TF-PCA in patients with type 1 and type 2 diabetes are different and should be further explored.

Diabetes does not alter mortality or hemostatic and inflammatory responses in patients with severe sepsis

OBJECTIVE

Diabetes patients have an increased risk of sepsis. Several inflammatory and coagulant pathways that are activated during sepsis are also up-regulated in diabetes patients. We tested our a priori hypothesis that the presence of diabetes adversely affects the outcome of sepsis.

DESIGN

Retrospective analysis of a previously published study.

SETTING

Intensive care units of 164 centers in 11 countries.

PATIENTS

Eight hundred thirty severe sepsis patients who were admitted to the intensive care unit and who received standard critical care treatment.

INTERVENTIONS

Patients were stratified into diabetic and nondiabetic patient groups. Mortality was assessed after 28 and 90 days, causative microorganisms were evaluated, and markers of coagulation, fibrinolysis, and inflammation were measured at several time points.

MEASUREMENTS AND MAIN RESULTS

Diabetes was present in 22.7% of all sepsis patients. Throughout the study, plasma glucose levels were higher in diabetic patients. Mortality was equal in diabetic and nondiabetic patients (31.4% vs. 30.5% after 28 days). Markers of coagulation, fibrinolysis, and inflammation were generally equal in diabetic and nondiabetic patients, although on admission diabetic patients had slightly higher levels of anticoagulation markers. Interestingly, nondiabetic patients with admission hyperglycemia (>11.1 mmol/L; 200 mg/dL) had a higher mortality rate compared to those without admission hyperglycemia (43.0% vs. 27.2%).

CONCLUSIONS

Although diabetes is a risk factor for sepsis, once established, the outcome of severe sepsis does not appear to be significantly influenced by the presence of diabetes. In nondiabetic patients, however, admission hyperglycemia is associated with an increased mortality.

Plasminogen activator inhibitor-1 is associated with coronary artery calcium in Type 1 diabetes

BACKGROUND

Elevated levels of plasminogen activator inhibitor-1 (PAI-1), the major inhibitor of fibrinolysis, is associated with coronary artery disease (CAD). This association may not be independent of factors related to insulin resistance (IR). Patients with Type 1 diabetes mellitus have increased CAD and an increase in sub-clinical CAD which develops earlier in life. It is not known if PAI-1 is associated with sub-clinical CAD in Type 1 diabetes or if this association is independent of IR.

METHODS AND RESULTS

Type 1 diabetes patients (n=560) and participants without diabetes (n=693) were assessed for coronary artery calcium (CAC), a surrogate for subclinical CAD, by electron-beam computed tomography. PAI-1 was associated with CAC in both Type 1 diabetes (OR=1.32, 95% CI=1.12-1.58) and non-diabetes (OR=1.34, 95% CI=1.13-1.58), after controlling for traditional risk factors not associated with IR. In Type 1 diabetes, the relationship between PAI-1 and CAC was strongest for younger participants (P=.02 for PAI-1-by-age interaction) after controlling for factors related to IR. PAI-1 was positively associated with CAC for Type 1 diabetes participants younger than 45 years of age.

CONCLUSION

PAI-1 levels are independently related to CAC in younger Type 1 diabetes participants. PAI-1 levels were not independently related to CAC in non-diabetes participants.

Effect of valsartan on monocyte/endothelial cell activation markers and adiponectin in hypertensive patients with type 2 diabetes mellitus

Angiotensin II receptor blockade has been shown to have a beneficial effect on the angiopathies of hypertension and hyperglycemia in patients with type 2 diabetes. However, the effect of angiotensin II receptor blockade on monocyte and endothelial cell adhesion markers in type 2 diabetes is poorly understood. We investigated the effects of valsartan on these markers in 53 hypertensive patients with and without type 2 diabetes mellitus. Levels of monocyte activation markers (soluble CD14: 2.1+/-0.9 vs. 3.3+/-1.4 microg/ml, p<0.01; monocyte chemotactic peptide: 392+/-94 vs. 489+/-114 pg/ml, p<0.05; and monocyte-derived microparticles: 264+/-98 vs. 511+/-128/microL, p<0.01) and endothelial cell activation markers (soluble E-selectin: 41+/-11 vs. 61+/-20 ng/ml, p<0.001; and soluble vascular cell adhesion molecule-1: 478+/-82 vs. 584+/-101 ng/ml, p<0.01) were significantly increased in hypertensive patients with type 2 diabetes compared to normotensive controls. In addition, the concentrations of adiponectin were significantly decreased in patients with type 2 diabetes (8.1+/-3.1 vs. 5.2+/-2.5 microg/ml, p<0.01). Regardless of the presence of diabetic complications, both systolic and diastolic blood pressures significantly decreased after valsartan administration (valsartan 80 mg/day for 8 weeks). Monocyte and endothelial cell activation markers were decreased significantly in patients with type 2 diabetes after valsartan treatment, but not in non-type 2 diabetic patients. In addition, valsartan alleviated hypoadiponectinemia in hypertensive patients with diabetes (before vs. after: 5.2+/-2.5 vs. 7.6+/-2.7 microg/ml, p<0.001) but did not increase adiponectin levels in the non-diabetic hypertensive group, for which the average adiponectin level was normal prior to treatment. These results suggest angiotensin II receptor blockade (valsartan) may be beneficial as an anti-atherosclerotic therapy in patients with type 2 diabetes in addition to its anti-hypertensive action.

Diabetes mellitus, hypothalamic hypoestrogenemia, and coronary artery disease in premenopausal women (from the National Heart, Lung, and Blood Institute sponsored WISE study)

Diabetes mellitus (DM) portends a higher risk of coronary heart disease mortality in women compared with men. This relationship appears to be independent of traditional cardiac risk factors, and the role of reproductive hormones has been postulated. We assessed the relationship between DM, hypothalamic hypoestrogenemia (HHE), angiographic coronary artery disease (CAD), and major adverse cardiovascular events (MACE) during a median of 5.9 years in premenopausal women enrolled in the WISE Study. We evaluated 95 premenopausal women from WISE who underwent coronary angiography for suspected ischemia and were not using exogenous reproductive hormones. Results showed no difference in age between women with (n = 30) and without (n = 65) DM (43 +/- 6 years). DM was associated with hypertension, HHE, angiographic CAD, and coronary artery severity score (all p <0.05). Women with DM were twice as likely to have HHE (50% vs 26%; p = 0.02) compared with women without DM. The presence of both DM and HHE was associated with increased prevalence (40% vs 12% or 13%; p = 0.006) and severity of angiographic CAD (coronary artery severity score 19.9 +/- 19.2 vs 7.7 +/- 4.6 or 12.3 +/- 18.8; p = 0.008) compared with either HHE or DM alone, respectively. DM was moderately predictive of MACE. In conclusion, in premenopausal women undergoing coronary angiography for suspected myocardial ischemia, DM was associated with HHE. The presence of both DM and HHE predicted a greater burden of angiographic CAD. Prospective research is warranted to better understand causal relations between DM, endogenous hormones, and MACE in premenopausal women.

Cardiovascular Risk Factors and Venous Thromboembolism

Background— The concept that venous thromboembolism (VTE) and atherosclerosis are 2 completely distinct entities has recently been challenged because patients with VTE have more asymptomatic atherosclerosis and more cardiovascular events than control subjects. We performed a meta-analysis to assess the association between cardiovascular risk factors and VTE.

Methods and Results— Medline and EMBASE databases were searched to identify studies that evaluated the prevalence of major cardiovascular risk factors in VTE patients and control subjects. Studies were selected using a priori defined criteria, and each study was reviewed by 2 authors who abstracted data on study characteristics, study quality, and outcomes. Odds ratios or weighted means and 95% confidence intervals (CIs) were then calculated and pooled using a random-effects model. Statistical heterogeneity was evaluated through the use of χ 2 and I 2 statistics. Twenty-one case-control and cohort studies with a total of 63 552 patients met the inclusion criteria. Compared with control subjects, the risk of VTE was 2.33 for obesity (95% CI, 1.68 to 3.24), 1.51 for hypertension (95% CI, 1.23 to 1.85), 1.42 for diabetes mellitus (95% CI, 1.12 to 1.77), 1.18 for smoking (95% CI, 0.95 to 1.46), and 1.16 for hypercholesterolemia (95% CI, 0.67 to 2.02). Weighted mean high-density lipoprotein cholesterol levels were significantly lower in VTE patients, whereas no difference was observed for total and low-density lipoprotein cholesterol levels. Significant heterogeneity among studies was present in all subgroups except for the diabetes mellitus subgroup. Higher-quality studies were more homogeneous, and significant associations remained unchanged.

Conclusions— Cardiovascular risk factors are associated with VTE. This association is clinically relevant with respect to individual screening, risk factor modification, and primary and secondary prevention of VTE. Prospective studies should further investigate the underlying mechanisms of this relationship.

Coma with diffuse white matter hemorrhages in juvenile diabetic ketoacidosis

Cerebral edema is the most common neurologic complication of diabetic ketoacidosis in children. A minority of young patients with intracerebral crises in diabetic ketoacidosis present with cerebrovascular accidents. We report 2 adolescent patients with diabetic ketoacidosis who presented with coma and diffuse white matter hemorrhages in the absence of either cerebral edema or cerebrovascular accidents. These 2 cases illustrate a novel clinical and neuropathologic description of diffuse white matter hemorrhages, possibly related to a cytotoxic process as the underlying mechanism. These case descriptions emphasize that pediatric patients with diabetic ketoacidosis and coma can present with pathology not related to either cerebral edema or cerebrovascular accidents.

Diabetes-associated macrovasculopathy: pathophysiology and pathogenesis

The complications associated with diabetic vasculopathy are commonly grouped into two categories: microvascular and macrovascular complications. In diabetes, macrovascular disease is the commonest cause of mortality and morbidity and is responsible for high incidence of vascular diseases such as stroke, myocardial infarction and peripheral vascular diseases. Macrovascular diseases are traditionally thought of as due to underlying obstructive atherosclerotic diseases affecting major arteries. Pathological changes of major blood vessels leading to functional and structural abnormalities in diabetic vessels include endothelial dysfunction, reduced vascular compliance and atherosclerosis. Besides, advanced glycation end product formation interacts with specific receptors that lead to overexpression of a range of cytokines. Haemodynamic pathways are activated in diabetes and are possibly amplified by concomitant systemic hypertension. Apart from these, hyperglycaemia, non-enzymatic glycosylation, lipid modulation, alteration of vasculature and growth factors activation contribute to development of diabetic vasculopathy. This review focuses on pathophysiology and pathogenesis of diabetes-associated macrovasculopathy.

Intensive insulin therapy in the intensive care unit: update on clinical impact and mechanisms of action

OBJECTIVE

Hyperglycemia is a common feature of the critically ill and has been associated with increased mortality. In this review, we give an overview of studies associating critical illness-induced hyperglycemia with adverse outcome and describe how mortality and morbidity are affected when blood glucose levels are strictly controlled to normoglycemia with intensive insulin therapy.

RESULTS

Maintaining normoglycemia with intensive insulin therapy improves survival rates and reduces morbidity in prolonged critically ill patients in both surgical and medical intensive care units (ICUs), as shown by 2 large randomized controlled studies. Prevention of cellular glucose toxicity by strict glycemic control appears to play a predominant role, but other metabolic and nonmetabolic effects of insulin also seem to contribute to the clinical benefits of this therapy.

CONCLUSION

These data support the generalized implementation of a strict blood glucose control management with intensive insulin therapy in adult surgical as well as medical ICU patients.

Altered chaperone and protein turnover regulators expression in cultured skin fibroblasts from type 1 diabetes mellitus with nephropathy

In type-1 diabetes mellitus (T1DM) with diabetic nephropathy (DN), accumulation of abnormal proteins in the kidney and other tissues may derive from constitutive alterations of intracellular protein recognition, assembly, and turnover. We characterized the proteins involved in these functions in cultured skin fibroblasts from long-term T1DM patients with [DN+] or without [DN-] nephropathy but similar metabolic control, and from matched healthy subjects. 2-D gel electrophoresis and MS-MALDI analysis were employed. The [DN+] T1DM patients, compared with the two other groups, exhibited increased abundance of a high-molecular weight isoform of protein disulphide-isomerase A3 and a decrease of two low-molecular weight isoforms. They also had increased levels of heat shock protein (HSP) 60 kDa isoform #A4, of HSP71 kDa isoform #A30, and of HSP27 kDa isoform #6, whereas the HSP27 kDa isoforms #A90 and #A71 were decreased. Cathepsin beta-2 (#40), the cation-independent mannose 6-phosphate receptor binding protein 1 (CIMPR) (#A27), and annexin 2 (#A9) were also decreased in the [DN+] T1DM patients, whereas the RNA-binding protein regulatory subunity (#38) and the translationally-controlled tumor protein (TCTP) (#A45) were increased. These changes of chaperone-like proteins in fibroblasts may highlight those of the kidney and be patho-physiologically related to the development of nephropathy in T1DM.

Impact of Diabetes, Patient Age, and Gender on the 30-Day Incidence of Stroke and Death in Patients Undergoing Carotid Artery Stenting with Embolus Protection: A Post-Hoc Subanalysis of a Prospective Multicenter Registry

PURPOSE

To assess the impact of diabetes, patient age, and gender on major periprocedural (30-day) complications (major and minor strokes, all-cause deaths) following carotid artery stenting (CAS).

METHODS

An exploratory analysis was performed of 695 patients (516 men; mean age 69.9+/-8.4 years) enrolled consecutively between September 1999 and September 2002 in a multicenter Italian/German registry of routine CAS using cerebral protection devices. There were 535 nondiabetic patients and 160 diabetic patients in the analysis.

RESULTS

Logistic regression analysis revealed that diabetes and age, but not gender, impacted the cumulative 30-day incidence of any stroke and death (OR 2.1, 95% CI 1.0 to 4.8, p = 0.068 and OR 1.06, 95% CI 1.01 to 1.12, p = 0.031, respectively), as well as the 30-day incidence of major strokes and deaths (OR 5.9, 95% CI 1.6 to 21.8, p = 0.007 and OR 1.13, 95% CI 1.02 to 1.25, p = 0.018, respectively). According to receiver-operating characteristic analysis, age had no discriminatory power to predict complications in nondiabetic patients, but an age of 75 years was identified as the optimal cut point to predict complications in diabetic patients. Compared with nondiabetic patients, diabetics > or =75 years had a 4.3 greater risk of experiencing any stroke or death (95% CI 1.3 to 12.3, p = 0.016) and a 12.0 greater risk of a major stroke or death (95% CI 2.1 to 66.5, p = 0.005). Diabetics <75 years had no increase in risk over that of nondiabetic patients.

CONCLUSION

Diabetic patients > or =75 years carry a significantly increased risk for strokes or death after protected CAS. The findings should be taken into consideration when treating elderly diabetic patients.

Involvement of heat shock factor-1 in glycated LDL-induced upregulation of plasminogen activator inhibitor-1 in vascular endothelial cells

Coronary artery disease is the predominant cause of death in diabetic patients. Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of plasminogen activators. Heat shock protein (Hsp) was upregulated in uncontrolled diabetic patients. Our previous studies demonstrated that glycated LDL stimulated the generation of PAI-1 from vascular endothelial cells. The present study examined the effect of glycated LDL on the expression of heat shock factor-1 (HSF1), a physiological transcription factor of Hsp, and the involvement of HSF-1 in glycated LDL-induced production of PAI-1 in cultured human umbilical vein endothelial cells (HUVECs) and coronary artery endothelial cells (HCAECs). Treatment with glycated LDL increased the expression of HSF1 and Hsp-70 compared with LDL in subconfluent HCAECs or HUVECs, and that was associated with an increase of PAI-1 expression. The transfection of HSF1 gene enhanced the expression of PAI-1 in endothelial cells. Small interference RNA against HSF1 prevented glycated LDL-induced upregulation of PAI-1 in HCAECs or HUVECs. Glycated LDL increased the binding of a nuclear protein to the PAI-1 promoter. The nuclear protein-DNA complex was supershifted by HSF1 antibody. The presence of an antioxidant, butylated hydroxytulene, during the glycation of LDL prevented glycated LDL-induced increases of the expression of HSF1 or PAI-1 in endothelial cells. The results suggest that HSF-1 is involved in glycated LDL-induced upregulation of PAI-1 in subconfluent vascular endothelial cells through the binding of HSF1 to PAI-1 promoter. Glyco-oxidation may contribute to glycated LDL-induced expression of HSF1 and PAI-1 in endothelial cells.

Insulin resistance, the metabolic syndrome, diabetes, and cardiovascular disease risk in women with PCOS

Polycystic ovary syndrome is the most common endocrinopathy of reproductive aged women affecting 6-10% of the population. Traditionally considered a reproductive disorder manifesting as chronic anovulation, infertility, and hyperandrogenism, management has primarily focused on short-term reproductive outcomes. Recently, however, significant metabolic aspects in conjunction with longer-term health sequealae of PCOS have been recognized. The metabolic features are primarily related to underlying insulin resistance (IR), which is now understood to play an important role in both the pathogenesis and long-term sequelae of PCOS.

Insulin resistance, the metabolic syndrome, diabetes, and cardiovascular disease risk in women with PCOS

Polycystic ovary syndrome is the most common endocrinopathy of reproductive aged women affecting 6-10% of the population. Traditionally considered a reproductive disorder manifesting as chronic anovulation, infertility, and hyperandrogenism, management has primarily focused on short-term reproductive outcomes. Recently, however, significant metabolic aspects in conjunction with longer-term health sequealae of PCOS have been recognized. The metabolic features are primarily related to underlying insulin resistance (IR), which is now understood to play an important role in both the pathogenesis and long-term sequelae of PCOS.

Adrenal gland-dependent augmentation of plasminogen activator inhibitor-1 expression in streptozotocin-induced diabetic mice

BACKGROUND

Diabetes is associated with an excess risk of cardiac events, and one risk factor for infarction is an elevated level of plasminogen activator inhibitor-1 (PAI-1).

OBJECTIVES AND METHODS

To evaluate whether the glucocorticoid hormones are involved in the diabetes-induced PAI-1 production, we examined expression profiles of PAI-1 mRNA in adrenalectomized (ADX) mice with streptozotocin (STZ)-induced diabetes.

RESULTS

The diabetes-induced augmentation of plasma PAI-1 levels and PAI-1 mRNA expression in the heart and lungs was completely normalized in diabetic ADX mice. The glucocorticoid receptor antagonist RU486 significantly, but only partly suppressed PAI-1 induction in STZ-induced diabetic mice, suggesting that factors other than glucocorticoids are also involved in PAI-1 induction provoked by diabetes.

CONCLUSION

Our results suggested that the adrenal gland plays a critical role in the progression of thrombosis in diabetic patients by inducing expression of the PAI-1 gene.

Tissue factor pathway inhibitor: structure, biology and involvement in disease

Tissue factor (TF)-initiated coagulation plays a significant role in the pathophysiology of many diseases, including cancer and inflammation. Tissue factor pathway inhibitor (TFPI) is a plasma Kunitz-type serine protease inhibitor, which modulates initiations of coagulation induced by TF. In a factor (F) Xa-dependent feedback system, TFPI binds directly and inhibits the TF-FVII/FVIIa complex. Normally, TFPI exists in plasma both as a full-length molecule and as variably carboxy-terminal truncated forms. TFPI also circulates in complex with plasma lipoproteins. The levels and the dual inhibitor effect of TFPI on FXa and TF-FVII/FVIIa complex offers insight into the mechanisms of various pathological conditions triggered by TF. The use of selective pharmacological inhibitors has become an indispensable tool in experimental haemostasis and thrombosis research. In vivo administration of recombinant TFPI (rTFPI) in an experimental animal model prevents thrombosis (and re-thrombosis after thrombolysis), reduces mortality from E. coli-induced-septic shock, prevents fibrin deposition on subendothelial human matrix and protects against disseminated intravascular coagulation (DIC). Thus, TFPI may play an important role in modulating TF-induced thrombogenesis and it may also provide a unique therapeutic approach for prophylaxis and/or treatment of various diseases. In this review, we consider structural and biochemical aspects of the TFPI molecule and detail its inhibitory mechanisms and therapeutic implications in various disease conditions.

Glucose metabolism and insulin therapy

Hyperglycemia is a common feature of the critically ill patient and has been associated with increased mortality. Maintaining normoglycemia with insulin therapy improves survival and reduces morbidity in surgical ICU patients, as shown by a large randomized controlled study. Prevention of glucose toxicity by strict glycemic control but also other metabolic and non-metabolic effects of insulin contribute to these clinical benefits.