Abnormalities of coagulation, platelet function, and fibrinolysis associated with syndromes of insulin resistance

A lone spike in blood glucose can enhance the thrombo-inflammatory response in cortical venules

How transient hyperglycemia contributes to cerebro-vascular disease has been a challenge to study under controlled physiological conditions. We use amplified, ultrashort laser-pulses to physically disrupt brain-venule endothelium at targeted locations. This vessel disruption is performed in conjunction with transient hyperglycemia from a single injection of metabolically active D-glucose into healthy mice. The observed real-time responses to laser-induced disruption include rapid serum extravasation, platelet aggregation, and neutrophil recruitment. Thrombo-inflammation is pharmacologically ameliorated by a platelet inhibitor, by a scavenger of reactive oxygen species, and by a nitric oxide donor. As a control, vessel thrombo-inflammation is significantly reduced in mice injected with metabolically inert L-glucose. Venules in mice with diabetes show a similar response to laser-induced disruption and damage is reduced by restoration of normo-glycemia. Our approach provides a controlled method to probe synergies between transient metabolic and physical vascular perturbations and can reveal new aspects of brain pathophysiology.

Lipid and Bone Effects of Heparin Use During Hemodialysis

Unfractionated heparin (UFH) and low-molecular-weight heparins (LMWHs) are commonly prescribed anticoagulants for chronic hemodialysis (HD). The dialysis population comprises a unique group that receives heparin three times per week for a long period, with potential long-term cumulative metabolic effects such as osteoporosis and worsening lipid profile. HD patients have approximately half the number of lipases as healthy individuals, and their lipid metabolism is limited because of this decrease as well as partially inhibited function. Administration of UFH or LMWHs for anticoagulation can lead to metabolic starvation despite high triglyceride levels at the end of HD. In vitro studies indicate that UFH and LMWHs inhibit osteoblasts and promote osteoclasts. In patients on HD, long-term use of UFH or LMWHs did not worsen chronic kidney disease-mineral bone disease. Further investigation is needed to elucidate the underlining mechanisms of UFH and LMWHs and their possible influences on maintenance HD patients.

Metabolic Score for Insulin Resistance (METS-IR) Predicts Adverse Cardiovascular Events in Patients with Type 2 Diabetes and Ischemic Cardiomyopathy

Purpose

This study aimed to evaluate the association between metabolic score for insulin resistance (METS-IR) and adverse cardiovascular events in patients with ischemic cardiomyopathy (ICM) and type 2 diabetes mellitus (T2DM).

Methods

METS-IR was calculated using the following formula: ln[(2 × fasting plasma glucose (mg/dL) + fasting triglyceride (mg/dL)] × body mass index (kg/m2)/(ln[high-density lipoprotein cholesterol (mg/dL)]). Major adverse cardiovascular events (MACEs) were defined as the composite outcome of nonfatal myocardial infarction, cardiac death, and rehospitalization for heart failure. Cox proportional hazards regression analysis was used to evaluate the association between METS-IR and adverse outcomes. The predictive value of METS-IR was evaluated by the area under the curve (AUC), continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Results

The incidence of MACEs increased with METS-IR tertiles at a 3‑year follow‑up. Kaplan‒Meier curves showed a significant difference in event-free survival probability between METS-IR tertiles (P<0.05). Multivariate Cox hazard regression analysis adjusting for multiple confounding factors showed that when comparing the highest and lowest METS-IR tertiles, the hazard ratio was 1.886 (95% CI:1.613-2.204; P<0.001). Adding METS-IR to the established risk model had an incremental effect on the predicted value of MACEs (AUC=0.637, 95% CI:0.605-0.670, P<0.001; NRI=0.191, P<0.001; IDI=0.028, P<0.001).

Conclusion

METS-IR, a simple score of insulin resistance, predicts the occurrence of MACEs in patients with ICM and T2DM, independent of known cardiovascular risk factors. These results suggest that METS-IR may be a useful marker for risk stratification and prognosis in patients with ICM and T2DM.

Metabolic Syndrome and Cardiometabolic Risk Factors in the Mixed Hypercholesterolemic Populations with Respect to Gender, Age, and Obesity in Asir, Saudi Arabia

This record study aimed to investigate the prevalence of metabolic syndrome (MetS) profiles regarding sex, age, and obesity for the riskier factor of cardiovascular diseases in a general population in Saudi Arabia. Laboratory and anthropometric measurements were performed on non-specific participants with variant ages and BMI in either sex. Serobiochemical changes were measured for metabolic profiles, i.e., A1C/FSG, TC, TGC, HDLC/LDLC, Vit.D, TSH/T4, Hb, and Cr. The study was applied in a Polyclinic, Abha, Saudi Arabia in 2020 G. The general population showed variable incidences of MetS profiles, such as 69.4% diabetes, 85.5% hypothyroidism, and 92.2% obesity. Hypothyroidism showed a higher incidence in women rather than in men, but men were more dyslipidemic, with higher TGC and LDLC but low HDLC, compared to women. Men <40 Y. showed diabetes and hypothyroidism, but elders were dyslipidemic. Women <40 Y. showed anemia and hypovitaminosis-D but were suffering from hypothyroidism at all ages. Diabetes, hypothyroidism, hypovitaminosis-D, and dyslipidemia were the main MetS components in both overweight and obese participants, and an incidence of more than 50% in each profile was recorded. Diabetes with hypertension was characteristic of obese participants rather than those overweight. About 66.1% of the mixed-hypercholesterolemic cases were diabetic, but 18.9% of the mixed-diabetic participants were hypercholesterolemic. Castelli's risk factors, CRI-I and CRI-II, and atherogenic indices, AIP and AC, were measured for evaluating the cardiac risk in different populations based on the AUC-ROC and cut-off values. Insulin-resistance marker (TyG) was also measured, showing considerable cut-off values for diabetic susceptibility in the lipidemic participants with higher TGC and TC rather than HDLC or LDLC. In conclusion, MetS showed higher susceptibility to sex and age with increased incidence in women rather than men. However, the cardiac risk was more susceptible to men of higher TGC and low HDLC than women. Type 2 Diabetes mellitus (T2DM) was more prominent in both elders (≥40 Y.) than younger ages of either sex. Anemia and deficiency of Vit. D was characteristic of young women (<40 Y.). Hypothyroidism affects young men <40 Y. but was recorded in women of all ages. Both dyslipidemia and diabetes could trigger CVD, showing higher cardiac risk in mixed-hypercholesterolemic men rather than women. Our study strongly suggests that the consumption of unhealthy junk food, tobacco smoking, lack of exercise, and physical inactivity could be conclusive evidence of MetS in the Saudi population.

Targeting hypercoagulation to alleviate Alzheimer's disease progression in metabolic syndrome

INTRODUCTION

Metabolic Syndrome (MetS) constitutes an important risk factor for Alzheimer's disease (AD); however, the mechanism linking these two disorders has not been completely elucidated. Hence, hypercoagulation may account for the missing hallmark connecting MetS and AD. The present review proposes how hemostatic imbalance triggered in MetS advances in the context of AD. MetS causes interruption of insulin signaling and inflammation, inciting insulin resistance in the brain. Subsequently, neuroinflammation and brain endothelial dysfunction are prompted that further intensify the exorbitant infiltration of circulating lipids and platelet aggregation, thereby causing hypercoagulable state, impairing fibrinolysis and eventually inducing prothrombic state in the brain leading to neurodegeneration.

OBJECTIVE

This study aims to understand the role of hypercoagulation in triggering the progression of neurodegeneration in MetS. It also offers a few interventions to prevent the progression of AD in MetS targeting hypercoagulation.

METHODS

Literature studies based on MetS related neurodegeneration, the impact of coagulation on aggravating obesity and AD via the mechanisms of BBB disruption, neuroinflammation, and hypofibrinolysis.

CONCLUSION

The present paper proposes the hypothesis that hypercoagulation might amplify MetS associated insulin resistance, neuroinflammation, BBB disruption, and amyloid beta accumulation which eventually leads to AD.

Pulmonary embolism: Age specific temporal trends in incidence and mortality in Denmark 1999-2018

BACKGROUND

Through the last two decades the prevention, diagnosis and treatment of pulmonary embolism (PE) has evolved along with demographic changes. The influence of these current transformations is important in the assessment of the future burden of PE. We aimed to describe age specific temporal trends in incidence of first-time PE and subsequent mortality.

METHODS

We identified patients ≥18 years of age with a first-time in-hospital diagnosis of PE in Danish national registers. By dividing patients into seven age groups (18-34, 35-44, 45-54, 55-65, 65-74, 75-84, >85 years), age specific incidence and 1-year mortality rates were calculated for four different calendar periods between 1999 and 2018.

RESULTS

From 1999 to 2018 65,478 patients with a first-time PE were identified. PE incidence per 100,000 person years increased during the study period in all age-groups (18-34 years: 10 to 18, 35-44 years: 18 to 35, 45-54: 26 to 63, 55-64 years: 42 to 123, 65-74 years: 92 to 229, 75-84 years: 166 to 383 and >85 years: 155 to 417), p_trend <0.0001 for all. During the study period 1-year mortality rate decreased from 4 to 2 per 10 person years in patients aged 65-74 years and this trend was found in all age groups (p_trend = 0.0001 for all).

CONCLUSION

Despite a decreasing mortality rate, incidence rate of PE increased in Denmark across all age groups from 1999 to 2018, reflecting improved sensitivity of diagnostic methods and changes in the burden of comorbid conditions, all together warranting a continuing need for early prevention of PE.

PAI-1 in Diabetes: Pathophysiology and Role as a Therapeutic Target

Hypofibrinolysis is a key abnormality in diabetes and contributes to the adverse vascular outcome in this population. Plasminogen activator inhibitor (PAI)-1 is an important regulator of the fibrinolytic process and levels of this antifibrinolytic protein are elevated in diabetes and insulin resistant states. This review describes both the physiological and pathological role of PAI-1 in health and disease, focusing on the mechanism of action as well as protein abnormalities in vascular disease with special focus on diabetes. Attempts at inhibiting protein function, using different techniques, are also discussed including direct and indirect interference with production as well as inhibition of protein function. Developing PAI-1 inhibitors represents an alternative approach to managing hypofibrinolysis by targeting the pathological abnormality rather than current practice that relies on profound inhibition of the cellular and/or acellular arms of coagulation, and which can be associated with increased bleeding events. The review offers up-to-date knowledge on the mechanisms of action of PAI-1 together with the role of altering protein function to improve hypofirbinolysis. Developing PAI-1 inhibitors may form for the basis of future new class of antithrombotic agents that reduce vascular complications in diabetes.

Clopidogrel resistance response in patients with coronary artery disease and metabolic syndrome: the role of hyperglycemia and obesity

BACKGROUND

Despite the proven benefits of clopidogrel combined aspirin therapy for coronary artery disease (CAD), CAD patients with metabolic syndrome (MS) still tend to have coronary thrombotic events. We aimed to investigate the influence of metabolic risk factors on the efficacy of clopidogrel treatment in patients with CAD undergoing percutaneous coronary intervention (PCI).

METHODS

Cohorts of 168 MS and 168 non-MS subjects with CAD identified by coronary angiography (CAG) were enrolled in our study. MS was defined by modified Adult Treatment Panel III criteria. All subjects had taken 100 mg aspirin and 75 mg clopidogrel daily for more than 1 month, and administered loading doses of 600 mg clopidogrel and 300 mg aspirin before PCI. Blood samples were taken 24 h after the loading doses of clopidogrel and aspirin. Platelet aggregation was measured using light transmittance aggregometry (LTA) and thrombelastography (TEG). Clopidogrel resistance was defined as more than 50% adenosine diphosphate (ADP) induced platelet aggregation as measured by TEG.

RESULTS

Platelet aggregation inhibition rate by ADP was significantly lower in patients with MS as measured both by TEG (55% ± 31% vs. 68% ± 32%; P < 0.001) and LTA (29% ± 23% vs. 42% ± 29%; P < 0.001). In the multivariate analysis, elderly [OR (95% CI): 1.483 (1.047-6.248); P = 0.002], obesity [OR (95% CI): 3.608 (1.241-10.488); P = 0.018], high fasting plasma glucose level [OR (95% CI): 2.717 (1.176-6.277); P = 0.019] and hyperuricemia [OR (95% CI): 2.583 (1.095-6.094); P = 0.030] were all statistically risk factors for clopidogrel resistance. CAD patients with diabetes and obesity were more likely to have clopidogrel resistance than the CAD patients without diabetes and obesity [75% (61/81) vs. 43% (67/156); P < 0.001].

CONCLUSIONS

CAD patients with MS appeared to have poorer antiplatelet response to clopidogrel compared to those without MS. Obesity, diabetes and hyperuricemia were all significantly associated with clopidogrel resistance.

Evaluation of Mean Platelet Volume values in lean women with polycystic ovary syndrome

Objective: Mean Platelet Volume (MPV) is an important indicator of platelet activation. It is known that MPV increases in patients with coronory artery disease, diabetes mellitus, atherosclerosis and Polycystic ovary syndrome (PCOS). Our aim was to measure the MPV in lean patients with polycystic ovary syndrome.

Methods: The present study was designed to examine the platelet function by measuring MPV in non-obese women with PCOS. A total of 50 outpatients with PCOS were included. The control group consisted of 50 healthy subjects. Serum platelet, MPV, and white blood cell (WBC) levels were compared and evaluated retrospectively in all participants. These values were compared by statistical analysis.

Results: There were no statistically significant difference in between groups regarding MPV (p═0.357), WBC (p═0,414) and platelet (p═0,666).

Conclusion: There are studies implying MPV increase in PCOS patients, in our patients MPV levels did not correlate with PCOS except for patients with obesity. We think that PCOS itself has no effect on MPV levels and obesity changes MPV levels.

Importance of insulin resistance to vascular repair and regeneration

Metabolic insulin resistance is apparent across a spectrum of clinical disorders, including obesity and diabetes, and is characterized by an adverse clustering of cardiovascular risk factors related to abnormal cellular responses to insulin. These disorders are becoming increasingly prevalent and represent a major global public health concern because of their association with significant increases in atherosclerosis-related mortality. Endogenous repair mechanisms are thought to retard the development of vascular disease, and a growing evidence base supports the adverse impact of the insulin-resistant phenotype upon indices of vascular repair. Beyond the impact of systemic metabolic changes, emerging data from murine studies also provide support for abnormal insulin signaling at the level of vascular cells in retarding vascular repair. Interrelated pathophysiological factors, including reduced nitric oxide bioavailability, oxidative stress, altered growth factor activity, and abnormal intracellular signaling, are likely to act in conjunction to impede vascular repair while also driving vascular damage. Understanding of these processes is shaping novel therapeutic paradigms that aim to promote vascular repair and regeneration, either by recruiting endogenous mechanisms or by the administration of cell-based therapies.

Plasminogen activator inhibitor type 1 regulates microglial motility and phagocytic activity

Background

Plasminogen activator inhibitor type 1 (PAI-1) is the primary inhibitor of urokinase type plasminogen activators (uPA) and tissue type plasminogen activators (tPA), which mediate fibrinolysis. PAI-1 is also involved in the innate immunity by regulating cell migration and phagocytosis. However, little is known about the role of PAI-1 in the central nervous system.

Methods

In this study, we identified PAI-1 in the culture medium of mouse mixed glial cells by liquid chromatography and tandem mass spectrometry. Secretion of PAI-1 from glial cultures was detected by ELISA and western blotting analysis. Cell migration was evaluated by in vitro scratch-wound healing assay or Boyden chamber assay and an in vivo stab wound injury model. Phagocytic activity was measured by uptake of zymosan particles.

Results

The levels of PAI-1 mRNA and protein expression were increased by lipopolysaccharide and interferon-γ stimulation in both microglia and astrocytes. PAI-1 promoted the migration of microglial cells in culture via the low-density lipoprotein receptor-related protein (LRP) 1/Janus kinase (JAK)/signal transducer and activator of transcription (STAT)1 axis. PAI-1 also increased microglial migration in vivo when injected into mouse brain. PAI-1-mediated microglial migration was independent of protease inhibition, because an R346A mutant of PAI-1 with impaired PA inhibitory activity also promoted microglial migration. Moreover, PAI-1 was able to modulate microglial phagocytic activity. PAI-1 inhibited microglial engulfment of zymosan particles in a vitronectin- and Toll-like receptor 2/6-dependent manner.

Conclusion

Our results indicate that glia-derived PAI-1 may regulate microglial migration and phagocytosis in an autocrine or paracrine manner. This may have important implications in the regulation of brain microglial activities in health and disease.

Regulation of adipose tissue energy availability through blood flow control in the metabolic syndrome

Maintenance of blood flow rate is a critical factor for tissue oxygen and substrate supply. The potentially large mass of adipose tissue deeply influences the body distribution of blood flow. This is due to increased peripheral resistance in obesity and the role of this tissue as the ultimate destination of unused excess of dietary energy. However, adipose tissue cannot grow indefinitely, and the tissue must defend itself against the avalanche of nutrients provoking inordinate growth and inflammation. In the obese, large adipose tissue masses show lower blood flow, limiting the access of excess circulating substrates. Blood flow restriction is achieved by vasoconstriction, despite increased production of nitric oxide, the vasodilatation effects of which are overridden by catecholamines (and probably also by angiotensin II and endothelin). Decreased blood flow reduces the availability of oxygen, provoking massive glycolysis (hyperglycemic conditions), which results in the production of lactate, exported to the liver for processing. However, this produces local acidosis, which elicits the rapid dissociation of oxyhemoglobin, freeing bursts of oxygen in localized zones of the tissue. The excess of oxygen (and of nitric oxide) induces the production of reactive oxygen species, which deeply affect the endothelial, blood, and adipose cells, inducing oxidative and nitrosative damage and eliciting an increased immune response, which translates into inflammation. The result of the defense mechanism for adipose tissue, localized vasoconstriction, may thus help develop a more generalized pathologic response within the metabolic syndrome parameters, extending its effects to the whole body.

Relationship of ovarian volume with mean platelet volume and lipid profile in patients with polycystic ovary syndrome

The aim of the present study was to evaluate the relationship between ovarian volume (OV) and mean platelet volume (MPV) in women with polycystic ovary syndrome (PCOS). Hormonal parameters and lipid profile of cases, and their relationship to OV were also assessed. Bilateral OV of 210 newly diagnosed PCOS patients and 100 healthy non-hirsute women were measured by ultrasonography. Blood samples were obtained for full blood count, hormone levels and for lipid profiles. It was found that MPV increased gradually as OV increased. This implies a higher risk of hypercoagulability and therefore an increased risk of future cardiovascular disease.

The PPAR-Platelet Connection: Modulators of Inflammation and Potential Cardiovascular Effects

Historically, platelets were viewed as simple anucleate cells responsible for initiating thrombosis and maintaining hemostasis, but clearly they are also key mediators of inflammation and immune cell activation. An emerging body of evidence links platelet function and thrombosis to vascular inflammation. peroxisome proliferator-activated receptors (PPARs) play a major role in modulating inflammation and, interestingly, PPARs (PPARβ/δ and PPARγ) were recently identified in platelets. Additionally, PPAR agonists attenuate platelet activation; an important discovery for two reasons. First, activated platelets are formidable antagonists that initiate and prolong a cascade of events that contribute to cardiovascular disease (CVD) progression. Dampening platelet release of proinflammatory mediators, including CD40 ligand (CD40L, CD154), is essential to hinder this cascade. Second, understanding the biologic importance of platelet PPARs and the mechanism(s) by which PPARs regulate platelet activation will be imperative in designing therapeutic strategies lacking the deleterious or unwanted side effects of current treatment options.

Polycystic ovary syndrome: focus on platelets and prothrombotic risk

OBJECTIVES

Subjects with polycystic ovary syndrome (PCOS) were shown to carry an increased long-term cardiovascular risk. Systemic inflammation and reactive leukocytosis have also been described in PCOS. Recent research suggests the presence of an increased thrombotic risk in these patients.

METHODS

We describe a cohort of PCOS patients presenting with persistent thrombocytosis. Our cohort included women aged 20-37 who also had moderate leukocytosis and neutrophilia. They showed normal mean platelet volume and platelet aggregation. We excluded any myeloproliferative conditions in all patients.

RESULTS

The mean platelet count and standard deviation (SD) at presentation were 587 ± 61 × 10/L (normal 140-440 × 10/L). Median C-reactive protein (CRP) was 1.66 (range 1.2-2.2, normal <1 mg/dL). The platelet counts did not correlate with the CRP levels in our patients (Pearson correlation coefficient 0.171 and 0.170, respectively, P = 0.08).

CONCLUSION

While the inflammatory state of PCOS could play a role in triggering an increased platelet count, the persistent thrombocytosis in our patients did not correlate with the CRP levels. Therefore, from an etiological perspective, thrombocytosis appears to be at least partially independent from the classical pathways of systemic inflammation. The preexisting procoagulant state in PCOS due to coagulation cascade stimulation, platelet activation, and endothelial dysfunction may be further fueled by the presence of persistent thrombocytosis. We propose a unique model for cardiovascular risk assessment in women with PCOS to include not only the classic cardiovascular risk factors, but also the parameters related to the proinflammatory and procoagulant tendencies manifested in PCOS.

Mean platelet volume is associated with insulin resistance in non-obese, non-diabetic patients with coronary artery disease

BACKGROUND AND PURPOSE

Mean platelet volume (MPV), an indicator of platelet activation, has been shown to be elevated in patients with coronary artery disease (CAD) in some studies. Insulin resistance contributes to increased platelet activation and it is one of the risk factors for CAD. The aim of this study was to assess the relationship between insulin resistance and MPV in non-obese, non-diabetic patients with CAD.

METHODS AND SUBJECTS

Seventy-seven non-obese, non-diabetic CAD patients were divided into two groups, insulin resistant and insulin sensitive according to the homeostasis model assessment insulin resistance index (HOMA-IR). The insulin-resistant group was composed of 45 patients (30 males/15 females; mean age 59.8±11.1 years). The insulin-sensitive group was composed of 32 patients (17 males/15 females; mean age 58.9±12.2 years).

RESULTS

Insulin and HOMA-IR values were significantly higher in insulin-resistant CAD patients than in insulin-sensitive CAD patients. The MPV values were significantly higher in insulin-resistant CAD patients than in insulin-sensitive CAD patients (8.6±1.0 fl vs. 8.0±0.7 fl; respectively, p=0.01). The MPV was poorly correlated with HOMA-IR (r=0.30, p=0.054) and insulin (r=0.22, p=0.053).

CONCLUSIONS

We have shown that MPV was significantly elevated in insulin-resistant non-obese, non-diabetic CAD patients when compared to insulin-sensitive non-obese, non-diabetic CAD patients.

The impact of body mass index on the one year outcomes of patients treated by percutaneous coronary intervention with Biolimus- and Sirolimus-eluting stents (from the LEADERS Trial)

The aim of this analysis was to assess the effect of body mass index (BMI) on 1-year outcomes in patients enrolled in a contemporary percutaneous coronary intervention trial comparing a sirolimus-eluting stent with a durable polymer to a biolimus-eluting stent with a biodegradable polymer. A total of 1,707 patients who underwent percutaneous coronary intervention were randomized to treatment with either biolimus-eluting stents (n = 857) or sirolimus-eluting stents (n = 850). Patients were assigned to 1 of 3 groups according to BMI: normal (<25 kg/m(2)), overweight (25 to 30 kg/m(2)), or obese (>30 kg/m(2)). At 1 year, the incidence of the composite of cardiac death, myocardial infarction, and clinically justified target vessel revascularization was assessed. In addition, rates of clinically justified target lesion revascularization and stent thrombosis were assessed. Cox proportional-hazards analysis, adjusted for clinical differences, was used to develop models for 1-year mortality. Forty-five percent of the patients (n = 770) were overweight, 26% (n = 434) were obese, and 29% (n = 497) had normal BMIs. At 1-year follow-up, the cumulative rate of cardiac death, myocardial infarction, and clinically justified target vessel revascularization was significantly higher in the obese group (8.7% in normal-weight, 11.3% in overweight, and 14.5% in obese patients, p = 0.01). BMI (hazard ratio 1.47, 95% confidence interval 1.02 to 2.14, p = 0.04) was an independent predictor of stent thrombosis. Stent type had no impact on the composite of cardiac death, myocardial infarction, and clinically justified target vessel revascularization at 1 year in the 3 BMI groups (hazard ratio 1.08, 95% confidence interval 0.63 to 1.83, p = 0.73). In conclusion, BMI was an independent predictor of major adverse cardiac events at 1-year clinical follow-up. The higher incidence of stent thrombosis in the obese group may suggest the need for a weight-adjusted dose of clopidogrel.

Platelet hyper-reactivity in active inflammatory arthritis is unique to the adenosine diphosphate pathway: a novel finding and potential therapeutic target

OBJECTIVE

To assess the influence of disease activity on platelet function in patients with inflammatory arthritis (IA).

METHODS

Ninety-six patients with an established diagnosis of IA (RA, PsA, seronegative SpA) were recruited. Patients with a history of cardiovascular disease (CVD), diabetes mellitus or receiving anti-platelet therapy were excluded. Demographic data, traditional CVD risk factors and medication use were recorded. Patients were characterized as active disease (n = 38) or control disease (n = 58) groups, respectively, based on internationally validated measures of disease activity [comprising serological markers (ESR, CRP, fibrinogen), patient measures (visual analogue scale of disease activity), evaluator global assessment and the 28-joint disease activity score]. Platelet function was assessed using a novel assay of platelet reactivity. Platelet aggregation to multiple concentrations of arachidonic acid, collagen, epinephrine, thrombin receptor activating peptide and adenosine diphosphate (ADP) were measured simultaneously using a modification of light transmission aggregometry.

RESULTS

The two groups (active vs control) were similar in terms of demographics and CVD risk factors. Anti-TNF-alpha therapy use was higher in the control group (P = 0.004), whereas NSAID use was higher in the active group (P = 0.001). There was a significant difference between the two groups in platelet response to ADP (P < 0.001). Platelet aggregation, in response to submaximal concentrations of ADP, was increased in the active disease group compared with the control group. There was no difference in platelet reactivity between the groups in response to any of the other agonists.

CONCLUSION

Patients with active IA demonstrate enhanced platelet reactivity, unique to the ADP pathway. This potential pro-thrombotic bias may contribute to their increased cardiovascular risk.

Correlates and consequences of venous thromboembolism: The Iowa Women's Health Study

OBJECTIVES

We sought to document incidence, case-fatality, and recurrence rates of venous thromboembolism (VTE) in women and to explore the relationship of demographic, lifestyle, and anthropometric factors to VTE incidence.

METHODS

Data from participants aged 55 to 69 years in the Iowa Women's Health Study were linked to Medicare data for 1986 through 2004 (n = 40 377) to identify hospitalized VTE patients.

RESULTS

A total of 2137 women developed VTE, yielding an incidence rate of 4.04 per 1000 person-years. The 28-day case-fatality rate was 7.7%, and the 1-year recurrence rate was 3.4%. Educational attainment, physical activity, and age at menopause were inversely associated with VTE. Risk of secondary (particularly cancer-related) VTE was higher among smokers than among those who had never smoked. Body mass index, waist circumference, waist-to-hip ratio, height, and diabetes were positively associated with VTE risk. Hormone replacement therapy use was associated with increased risk of idiopathic VTE.

CONCLUSIONS

VTE is a significant source of morbidity and mortality in older women. Risk was elevated among women who were smokers, physically inactive, overweight, and diabetic, indicating that lifestyle contributes to VTE risk.

Acute coronary thrombosis in a patient with diabetes and severe hyperglycemia

The pathophysiological processes responsible for acute coronary events in diabetic patients, in addition to the conventional factors associated with plaque rupture, include an enhanced prothrombotic state. This enhanced prothrombotic state results from multiple abnormalities of the coagulation system including platelet activation, impaired fibrinolysis and increased activity of the coagulation cascade. Studies have also demonstrated that severe hyperglycemia can result in an exacerbation of the underlying pro-thrombotic state, indicating that patients with extreme hyperglycemia are subject to an even greater thrombotic risk. The present case illustrates the thrombotic hazards associated with severe hyperglycemia.

Metabolic syndrome and risk of venous thromboembolism: Longitudinal Investigation of Thromboembolism Etiology

SUMMARY BACKGROUND

In a recent case-control study, the odds of metabolic syndrome (MetSyn) among deep vein thrombosis cases were almost twice those among controls. We tested the hypothesis that the incidence of non-cancer-related venous thromboembolism (VTE) is higher among adults with MetSyn and further, that associations are stronger for idiopathic than secondary VTE.

METHODS

A total of 20 374 middle-aged and elderly adults were followed for over 12 years for incident VTE in the Longitudinal Investigation of Thromboembolism Etiology (LITE). All hospitalizations were identified and VTEs validated by chart review. Baseline MetSyn was defined using ATP III guidelines, including >or=3 of the following components: abdominal obesity, elevated blood pressure, low HDL-cholesterol, high triglycerides and high glucose. Because sex modified the relation between MetSyn and VTE (p(interaction) = 0.001), proportional hazards regression analyses were stratified by sex to assess the associations of MetSyn and its components with risk of incident non-cancer-related VTE, adjusting for potential confounders.

RESULTS

Incident VTE (n = 358) included 196 idiopathic events. Baseline MetSyn was associated with risk of total VTE (hazard ratio (HR) = 1.84, 95% CI = 1.30, 2.59) and idiopathic VTE (HR = 1.59, 95% CI = 1.02, 2.47) among men, but not women. The association was largely attributable to abdominal obesity (HR of VTE = 2.10, 95% CI = 1.51, 2.93, in men; HR of VTE = 1.70, 95% CI = 1.24, 2.34, in women), with no additional contribution by the other MetSyn components.

CONCLUSION

Although abdominal obesity was associated with increased risk of VTE in both men and women, MetSyn and its other components do not seem important in VTE etiology.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The metabolic syndrome

The "metabolic syndrome" (MetS) is a clustering of components that reflect overnutrition, sedentary lifestyles, and resultant excess adiposity. The MetS includes the clustering of abdominal obesity, insulin resistance, dyslipidemia, and elevated blood pressure and is associated with other comorbidities including the prothrombotic state, proinflammatory state, nonalcoholic fatty liver disease, and reproductive disorders. Because the MetS is a cluster of different conditions, and not a single disease, the development of multiple concurrent definitions has resulted. The prevalence of the MetS is increasing to epidemic proportions not only in the United States and the remainder of the urbanized world but also in developing nations. Most studies show that the MetS is associated with an approximate doubling of cardiovascular disease risk and a 5-fold increased risk for incident type 2 diabetes mellitus. Although it is unclear whether there is a unifying pathophysiological mechanism resulting in the MetS, abdominal adiposity and insulin resistance appear to be central to the MetS and its individual components. Lifestyle modification and weight loss should, therefore, be at the core of treating or preventing the MetS and its components. In addition, there is a general consensus that other cardiac risk factors should be aggressively managed in individuals with the MetS. Finally, in 2008 the MetS is an evolving concept that continues to be data driven and evidence based with revisions forthcoming.

Platelet reactivity and response to aspirin in subjects with the metabolic syndrome

BACKGROUND

Metabolic syndrome (MS) is associated with a prothrombotic state and predicts the subsequent development of type 2 diabetes mellitus. We hypothesized that similar to diabetes, subjects with MS may have increased platelet reactivity, and reduced response to aspirin. We, therefore, compared platelet reactivity and response to aspirin among subjects with MS and healthy volunteers.

METHODS

Fifty subjects with MS, defined by Adult Treatment Panel III criteria (age 44+/-9 years, 80% women, body mass index 35+/-8 kg/m2) were compared to 50 healthy controls who met none of the MS criteria (age 40+/-7 years, 80% women, body mass index: 24+/-3 kg/m2). Blood samples were taken before and 24 hours after 325 mg aspirin (single dose). Platelet function was evaluated by aggregation in response to 1.5 mmol/L arachidonic acid, 1 microg/mL collagen, and 5 and 20 micromol/L adenosine diphosphate; the VerifyNow Aspirin assay (Accumetrics Inc, San Diego, CA); Impact-R Cone and Plate(let) Analyzer (shear-dependent test) (DiaMed, Cresier, Switzerland) and flow cytometric determination of P-selectin expression and activated glycoprotein IIb/IIIa expression; and reticulated platelets (reflecting platelet turnover).

RESULTS

Subjects with MS had higher baseline P-selectin levels (14.5+/-5 vs 11.3+/-4 mean fluorescence intensity, P=.002), reticulated platelets (2.8%+/-3% vs 1.2%+/-1%, P=.04) and platelet deposition under flow (Impact-R 7.5%+/-2% vs 5.9%+/-2%, P=.003). Subjects with MS also had lower response to aspirin, as evaluated by the change in all platelet aggregation assays and the VerifyNow score.

CONCLUSIONS

Subjects with MS appear to have increased baseline platelet reactivity and turnover and a lower antiplatelet response to aspirin. Further research is required to elucidate platelet properties in subjects with MS and find ways to modify them.

Metabolic syndrome is a predictor for an ECG sign of no-reflow after primary PCI in patients with acute ST-elevation myocardial infarction

BACKGROUND AND AIM

The purpose of this study was to evaluate both the predictive value of metabolic syndrome (MS) on no-reflow phenomenon and 30-day clinical outcomes on patients undergoing primary percutaneous coronary intervention (PCI) for acute ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

One hundred and twelve consecutive patients (mean age 57+/-11 years, 94 male) with acute STEMI treated with primary PCI were analysed prospectively. Sum of ST-segment elevation was obtained immediately before and 60 min after the restoration of TIMI-3 flow. The difference between two measurements was accepted as the amount of ST-segment resolution and was expressed as summation operatorSTR. summation operatorSTR<50% was accepted as ECG sign of no-reflow phenomenon. Metabolic syndrome was defined based on Adult Treatment Panel-III criteria. The no-reflow was found in 22.3% of the entire group and was significantly higher in patients with MS than those without MS (43.7% vs. 13.7%, p<0.001). There was no significant difference in no-reflow between patients who had both MS and diabetes mellitus (DM) and patients who had MS but not DM (42.5% vs. 50%, respectively; p>0.05).

CONCLUSION

The presence of MS may play an important role in the occurrence of no- reflow in STEMI treated with primary PCI.

Symptoms and treatments of polycystic ovary syndrome

Up to 10% of women may suffer from polycystic ovary syndrome (PCOS). The clinical symptoms may vary, so the biochemical profile and ultrasonography are used to predict an accurate diagnosis. Many studies have indicated that a relationship may exist between hyperinsulineamia and hyperandrogenism but the exact pathogenesis remains obscure. PCOS is treated by a combination of surgery or pharmacological management. Treatment is not always successful therefore women in these cases require support and care from nursing staff to help overcome the disappointment of treatment failure. To support women with PCOS, nurses need to be knowledgeable about the condition and its clinical manifestations and available treatment options. This article aims to examine the current aetiology, clinical manifestations, pathophysiology, diagnosis and treatment options available to women with a diagnosis of PCOS.

Long-term effects of pioglitazone versus gliclazide on hepatic and humoral coagulation factors in patients with type 2 diabetes

This study compared the long-term effects of pioglitazone and gliclazide on the production of coagulation factors in patients with type 2 diabetes. Patients (n=283) with glycosylated haemoglobin > 7.5% were randomised to receive either pioglitazone (30-45 mg/day) or gliclazide (80-320 mg/day) for one year. Coagulation factors were measured at baseline and at six and 12 months. While both pioglitazone and gliclazide induced a comparable improvement in glycaemic control, only pioglitazone improved insulin sensitivity. Pioglitazone significantly (p < or = 0.001) decreased circulating levels of von Willebrand factor (-9.7%, -9.4%) and plasminogen activator inhibitor-1 (-16.8 ng/ml, -12.3 ng/ml), and increased levels of antithrombin-III (+1.3 mg/dL, +1.5 mg/dL) after six and 12 months, respectively. The beneficial effects of pioglitazone on glycaemic control, lipid homeostasis, and coagulation and thrombosis, may improve vascular outcomes in patients with type 2 diabetes.

Safety and efficacy of catheter ablation of atrial fibrillation in patients with diabetes mellitus—single center experience

BACKGROUND AND OBJECTIVE

Little is known about the outcome of catheter ablation of atrial fibrillation (AF) in patients with diabetes mellitus (DM). We investigated the safety and efficacy of catheter ablation of AF in patients with DM.

MATERIALS AND METHODS

Thirty one patients with DM from a group of 263 consecutive patients undergoing a first-time catheter ablation of AF procedure were enrolled in a prospective study. The ablation protocol (guided by CARTO system) consisted in two continuous circular lesions around ipsilateral pulmonary veins.

RESULTS

The following clinical characteristics differed between DM and no-DM patients: age (62.0 +/- 10.8 vs. 56.1 +/- 10.6 years, P = 0.004), longer AF history (9.6 +/- 9.3 vs. 6.7 +/- 6.3 years, P = 0.024), significantly larger left atrium size (41.1 +/- 7.8 vs. 38.3 +/- 5.8 mm, P = 0.021), hypertension (58.1 vs. 35.8%, P = 0.018) and structural heart disease (67.7 vs. 43.5%, P = 0.011). Despite a similar AF recurrence rate in DM and no-DM patients (32.3 vs. 22.4%, P = 0.240), the ablation procedure was complicated in 28 patients (11 hematomas, three cardiac tamponades and three strokes) and the incidence of complications was significantly higher in DM than in no-DM patients (29.0 vs. 8.2%, respectively, P = 0.002). Multivariate analysis showed that DM was an independent risk factor for complications occurrence (odd ratio 5.936, 95% confidence interval 2.059 to 17.112, P = 0.001).

CONCLUSIONS

First catheter ablation of AF procedure in DM patients was equally efficacious than in no-DM patients. However, DM patients had a higher incidence of complications, mostly thrombotic or hemorrhagic.

From vulnerable plaque to vulnerable patient--Part III: Executive summary of the Screening for Heart Attack Prevention and Education (SHAPE) Task Force report

Screening for early-stage asymptomatic cancers (eg, cancers of breast and colon) to prevent late-stage malignancies has been widely accepted. However, although atherosclerotic cardiovascular disease (eg, heart attack and stroke) accounts for more death and disability than all cancers combined, there are no national screening guidelines for asymptomatic (subclinical) atherosclerosis, and there is no government- or healthcare-sponsored reimbursement for atherosclerosis screening. Part I and Part II of this consensus statement elaborated on new discoveries in the field of atherosclerosis that led to the concept of the "vulnerable patient." These landmark discoveries, along with new diagnostic and therapeutic options, have set the stage for the next step: translation of this knowledge into a new practice of preventive cardiology. The identification and treatment of the vulnerable patient are the focuses of this consensus statement. In this report, the Screening for Heart Attack Prevention and Education (SHAPE) Task Force presents a new practice guideline for cardiovascular screening in the asymptomatic at-risk population. In summary, the SHAPE Guideline calls for noninvasive screening of all asymptomatic men 45-75 years of age and asymptomatic women 55-75 years of age (except those defined as very low risk) to detect and treat those with subclinical atherosclerosis. A variety of screening tests are available, and the cost-effectiveness of their use in a comprehensive strategy must be validated. Some of these screening tests, such as measurement of coronary artery calcification by computed tomography scanning and carotid artery intima-media thickness and plaque by ultrasonography, have been available longer than others and are capable of providing direct evidence for the presence and extent of atherosclerosis. Both of these imaging methods provide prognostic information of proven value regarding the future risk of heart attack and stroke. Careful and responsible implementation of these tests as part of a comprehensive risk assessment and reduction approach is warranted and outlined by this report. Other tests for the detection of atherosclerosis and abnormal arterial structure and function, such as magnetic resonance imaging of the great arteries, studies of small and large artery stiffness, and assessment of systemic endothelial dysfunction, are emerging and must be further validated. The screening results (severity of subclinical arterial disease) combined with risk factor assessment are used for risk stratification to identify the vulnerable patient and initiate appropriate therapy. The higher the risk, the more vulnerable an individual is to a near-term adverse event. Because <10% of the population who test positive for atherosclerosis will experience a near-term event, additional risk stratification based on reliable markers of disease activity is needed and is expected to further focus the search for the vulnerable patient in the future. All individuals with asymptomatic atherosclerosis should be counseled and treated to prevent progression to overt clinical disease. The aggressiveness of the treatment should be proportional to the level of risk. Individuals with no evidence of subclinical disease may be reassured of the low risk of a future near-term event, yet encouraged to adhere to a healthy lifestyle and maintain appropriate risk factor levels. Early heart attack care education is urged for all individuals with a positive test for atherosclerosis. The SHAPE Task Force reinforces existing guidelines for the screening and treatment of risk factors in younger populations. Cardiovascular healthcare professionals and policymakers are urged to adopt the SHAPE proposal and its attendant cost-effectiveness as a new strategy to contain the epidemic of atherosclerotic cardiovascular disease and the rising cost of therapies associated with this epidemic.

The metabolic syndrome, depression, and cardiovascular disease: interrelated conditions that share pathophysiologic mechanisms

This article introduces the metabolic syndrome as a clinical phenotype with consequences for diagnosis and treatment that go beyond the different clinical specialties involved. A life-course approach is suggested as a means of understanding the complex interrelations between the metabolic syndrome, depression, and cardiovascular disease. Pathophysiologic mechanisms that these conditions share are discussed in detail. These considerations provide arguments for a more integrative approach to patients in general that surpass the current disease-centered services such as endocrinology, psychiatry, and cardiology.