Platelet hyperprocoagulant activity in Type 2 diabetes mellitus: attenuation by glycoprotein IIb/IIIa inhibition

Diabetes Mellitus in Acute Coronary Syndrome

The global prevalence of diabetes mellitus (DM) has led to a pandemic, with significant microvascular and macrovascular complications including coronary artery disease (CAD), which worsen clinical outcomes and cardiovascular prognosis. Patients with both acute coronary syndrome (ACS) and DM have worse prognosis and several pathophysiologic mechanisms have been implicated including, insulin resistance, hyperglycemia, endothelial dysfunction, platelet activation and aggregations as well as plaque characteristics and extent of coronary lesions. Therefore, regarding reperfusion strategies in the more complex anatomies coronary artery bypass surgery may be the preferred therapeutic strategy over percutaneous coronary intervention while both hyperglycemia and hypoglycemia should be avoided with closed monitoring of glycemic status during the acute phase of myocardial infraction. However, the best treatment strategy remains undefined. Non-insulin therapies, due to the low risk of hypoglycemia concurrently with the multifactorial CV protective effects, may be proved to be the best treatment option in the future. Nevertheless, evidence for the beneficial effects of glucagon like peptide-1 receptor agonists, dipeptidyl-peptidase 4 inhibitors and sodium glycose cotransporter 2 inhibitors, despite accumulating, is not robust and future randomized control trials may provide more definitive data.

Quantifying Shear-induced Margination and Adhesion of Platelets in Microvascular Blood Flow

Platelet margination and adhesion are two critical and closely related steps in thrombus formation. Using dissipative particle dynamics (DPD) method that seamlessly models blood cells, blood plasma, and vessel walls with functionalized surfaces, we quantify the shear-induced margination and adhesion of platelets in microvascular blood flow. The results show that the occurrence of shear-induced RBC-platelet collisions has a remarkable influence on the degree of platelet margination. We characterize the lateral motion of individual platelets by a mean square displacement analysis of platelet trajectories, and find that the wall-induced lift force and the shear-induced displacement in wall-bounded flow cause the variation in near-wall platelet distribution. We then investigate the platelet adhesive dynamics under different flow conditions, by conducting DPD simulations of blood flow in a microtube with fibrinogen-coated wall surfaces. We find that the platelet adhesion is enhanced with the increase of fibrinogen concentration level but decreased with the increase of shear rate. These results are consistent with available experimental results. In addition, we demonstrate that the adherent platelets have a negative impact on the margination dynamics of the circulating platelets, which is mainly due to the climbing effect induced by the adherent ones. Taken together, these findings provide useful insights into the platelet margination and adhesion dynamics, which may facilitate the understanding of the predominant processes governing the initial stage of thrombus formation.

Effectiveness of Platelet-Rich Plasma for Patients With Carpal Tunnel Syndrome: A Systematic Review and meta-Analysis of Current Evidence in Randomized Controlled Trials

Background: Recently, there was a series of clinical studies focusing on local injection of platelet-rich plasma (PRP) for treatment of patients with carpal tunnel syndrome (CTS). However, the safety and efficacy of PRP in these CTS patients remains controversial. Therefore, we performed a systematic review to compare PRP with other conservative treatments in treatment of CTS patients.

Methods: We systematically searched from electronic databases (Cochrane, PubMed, Web of Science, and EMBASE) up to 10 December 2021. The data of clinical results were extracted and analyzed by RevMan Manager 5.4.

Results: Finally, eight randomized controlled studies, involving 220 CTS patients undergoing local injection of PRP were enrolled in this systematic review. All enrolled trials were considered to be of high quality. In the short-term efficacy, the PRP group was significantly lower in symptom severity scale (SSS) compared with the control group (MD = −2.00; 95% CI, −3.15 to −0.85; p = 0.0007; I² = 0%). In the mid-term efficacy, the PRP group was significantly effective than the control group in the visual analogue scale (MD = −0.63; 95% CI, −1.22 to −0.04; p = 0.04; I² = 61%), SSS (MD = −3.56; 95% CI, −4.93 to −2.18; p < 0.00001; I² = 0%), functional status scale (MD = −2.29; 95% CI, −3.03 to −1.56; p < 0.00001; I² = 45%), sensory peak latency (MD = −0.39; 95% CI, −0.58 to −0.19; p = 0.0001; I² = 0%) and cross-sectional area of median nerve (MD = -0.20; 95% CI, −0.31 to −0.10; p = 0.0002; I² = 0%). In the mid-long-term efficacy, the PRP group was only significantly lower in SSS compared with the control group (MD = −2.71; 95% CI, −4.33 to −1.10; p = 0.001; I² = 38%).

Conclusion: Local PRP injection is more effective than other conservative treatments in terms of mid-term efficacy in relieving pain, improving wrist function and symptoms, reducing MN swelling, and partially improving electrophysiological indicators. However, the long-term adverse side and consensus on standardization of PRP in CTS patients still need further large-scale trials.

Diabetes and Thrombosis: A Central Role for Vascular Oxidative Stress

Diabetes mellitus is the fifth most common cause of death worldwide. Due to its chronic nature, diabetes is a debilitating disease for the patient and a relevant cost for the national health system. Type 2 diabetes mellitus is the most common form of diabetes mellitus (90% of cases) and is characteristically multifactorial, with both genetic and environmental causes. Diabetes patients display a significant increase in the risk of developing cardiovascular disease compared to the rest of the population. This is associated with increased blood clotting, which results in circulatory complications and vascular damage. Platelets are circulating cells within the vascular system that contribute to hemostasis. Their increased tendency to activate and form thrombi has been observed in diabetes mellitus patients (i.e., platelet hyperactivity). The oxidative damage of platelets and the function of pro-oxidant enzymes such as the NADPH oxidases appear central to diabetes-dependent platelet hyperactivity. In addition to platelet hyperactivity, endothelial cell damage and alterations of the coagulation response also participate in the vascular damage associated with diabetes. Here, we present an updated interpretation of the molecular mechanisms underlying vascular damage in diabetes, including current therapeutic options for its control.

Extracellular Vesicles and MicroRNA: Putative Role in Diagnosis and Treatment of Diabetic Retinopathy

Diabetic retinopathy (DR) is a complex, progressive, and heterogenous retinal degenerative disease associated with diabetes duration. It is characterized by glial, neural, and microvascular dysfunction, being the blood-retinal barrier (BRB) breakdown a hallmark of the early stages. In advanced stages, there is formation of new blood vessels, which are fragile and prone to leaking. This disease, if left untreated, may result in severe vision loss and eventually legal blindness. Although there are some available treatment options for DR, most of them are targeted to the advanced stages of the disease, have some adverse effects, and many patients do not adequately respond to the treatment, which demands further research. Oxidative stress and low-grade inflammation are closely associated processes that play a critical role in the development of DR. Retinal cells communicate with each other or with another one, using cell junctions, adhesion contacts, and secreted soluble factors that can act in neighboring or long-distance cells. Another mechanism of cell communication is via secreted extracellular vesicles (EVs), through exchange of material. Here, we review the current knowledge on deregulation of cell-to-cell communication through EVs, discussing the changes in miRNA expression profiling in body fluids and their role in the development of DR. Thereafter, current and promising therapeutic agents for preventing the progression of DR will be discussed.

Platelet aggregation is not altered among men with diabetes mellitus

AIMS

Platelets are pivotal in arterial thrombosis, and platelet hyperresponsiveness may contribute to the increased incidence of cardiovascular events in diabetes mellitus. Consequently, we hypothesized that increased in vitro platelet aggregation responses exist in men with diabetes mellitus.

METHODS

The Danish Cardiovascular Screening Trial (DANCAVAS) is a community-based cardiovascular screening trial including men aged 65-74 years. Platelet aggregation was tested using 96-well light transmission aggregometry with thrombin receptor-activating peptide (TRAP), adenosine diphosphate, collagen type 1, arachidonic acid and protease-activated receptor-4 in three concentrations. Further, cardiovascular risk factors and coronary artery calcification (CAC), estimated by CT scans and ankle-brachial index, were obtained.

RESULTS

Included were 720 men aged 65-74 years, 110 with diabetes mellitus. Overall, there was no difference in platelet aggregation among men with versus without diabetes mellitus when adjusting for or excluding platelet inhibitor treatment and men with established cardiovascular disease (CVD). This was true for all agonists, e.g., 10 µM TRAP-induced platelet aggregation of median 69% (IQR 53-75) versus 70% (IQR 60-76) in men with versus without diabetes mellitus. Platelet aggregation did not correlate with HbA_1c or CAC. Men with diabetes mellitus displayed higher CAC, median 257 Agatston units (IQR 74-1141) versus median 111 Agatston units (IQR 6-420) in the remaining individuals, p < 0.0001.

CONCLUSIONS

Among outpatients with diabetes mellitus, but no CVD and no platelet inhibitor treatment, neither are platelets hyperresponsive in diabetes mellitus, nor is platelet aggregation associated with glycemic status or with the degree of coronary atherosclerosis.

TRIAL REGISTRATION

ISRCTN12157806.

Aspirin in the primary prevention of cardiovascular disease in diabetes mellitus: A new perspective

Although the improved control of hyperglycaemia and other cardiovascular risk factors was associated with a parallel decline of atherosclerotic cardiovascular disease (ASCVD) and death in both type 1 (T1) and type 2 (T2) diabetes mellitus (DM), the burden of death and hospitalization for ASCVD remains significantly higher by about 2-fold versus the matched non-DM population. Life style interventions, such as physical activity and healthy diet, and drugs, such as statins and low-dose aspirin, may have beneficial effects by targeting one or multiple pathways responsible for accelerated atherosclerosis and its thrombotic complications. The debate on the benefit-risk balance of primary cardiovascular prevention with aspirin has been especially vivacious over the past two years, following the publication of three large randomized, placebo-controlled, primary prevention trials in different settings, spanning from healthy elderly to DM subjects. The aim of this review is to discuss the pathophysiological, pharmacological and clinical evidence supporting the appropriate use of low-dose aspirin in DM, within the context of the current multifactorial approach to primary cardiovascular prevention.

Endothelial HNF4α potentiates angiogenic dysfunction via enhancement of vascular endothelial growth factor resistance in T2DM

Although both hyperprocoagulant status, characterized by elevated thrombin levels, and vascular endothelial growth factor (VEGF) resistance, marked by attenuated expression of VEGFR2 (also called FLK1 or KDR), are known to contribute importantly to an increased risk of vascular events in diabetes mellitus type 2 (T2DM), it remains obscure whether these two biological events regulate angiogenic response in a coordinated manner. We show here that endothelial expression of hepatocyte nuclear factor 4α (HNF4α) was significantly upregulated in rodents and humans with T2DM, and HNF4α upregulation by thrombin was dependent on activation of multiple pathways, including protein kinase B, c-Jun N-terminal kinase, p38, oxidative stress, protein kinase C, and AMPK (5'-adenosine monophosphate (AMP)-activated protein kinase). Functionally, HNF4α inhibited VEGF-mediated endothelial proliferation and migration, and blunted VEGF-stimulated in vitro angiogenesis, thus rendering endothelial cells unresponsive to established angiogenic VEGF stimulation. Mechanistically, HNF4α potentiated the endothelial VEGF resistance through the direct transcriptional repression of FLK1 gene. From a therapeutic standpoint, overexpression of the exogenous FLK1 successfully rescued HNF4α-inhibited angiogenic response to VEGF and potentiated VEGF-stimulated in vitro tube formation. Considering a strong association between HNF4A deregulation and increased risk of T2DM, our findings suggest that HNF4α may act as a critical converging point linking hyperprocoagulant condition to VEGF resistance in diabetic ECs, and repression of FLK1 expression by thrombin-induced HNF4α mediates, at least partially, the vascular dysfunction caused by T2DM.

Aerobic training improves platelet function in type 2 diabetic patients: role of microRNA-130a and GPIIb

AIMS

MicroRNAs (miRs) that are mediators of gene expression have been implicated in type 2 diabetes mellitus (T2DM). Platelet hyper-reactivity is one of the most important disorders in T2DM patients. In this study, we explored the effects of aerobic training (AT) on platelet aggregation and Glycoprotein IIb (GPIIb) receptor and miR-130a expression.

METHODS

In a quasi-experimental controlled trial, 24 sedentary, eligible female participants with T2DM were selected (age 61.92 ± 3.63) and divided into AT and control (CON) groups based on their peak oxygen consumption (VO_2peak). AT protocol was performed three times per week in non-consecutive days on a treadmill with mean intensity (60-75% VO_2peak) for 8 weeks, while the control group refrained from any type of exercise training. Two blood samples were taken before and after this period. Real-time PCR was used to determine the expression of platelet GPIIb and miR-130a. Moreover, platelet indices (PLT, MPV, PDW, and PCT), collagen-induced platelet aggregation and glycemic variables were measured.

RESULTS

Analyses of data showed that anthropometric variables, VO_2peak and glycemic control improved significantly (P < 0.01) after AT. Furthermore, MPV, PDW (P < 0.01), and platelet aggregation (P < 0.001) decreased significantly following AT compared with control group. Platelet GPIIb expression down-regulated significantly (P < 0.05) in AT group but up-regulation of miR-130a expression was not significant between two groups (P > 0.05).

CONCLUSIONS

Platelet hyper-reactivity in T2DM females might be decreased not only by glycemic control and amelioration of anthropometric and platelet indices, but also the down-regulation of GPIIb following AT. However, more research is needed to determine the effects of exercise training on platelet miR-130a.

Pathogenic roles of microvesicles in diabetic retinopathy

Diabetic retinopathy (DR) is a common complication of diabetes and has been recognized as the leading cause of blindness in adults. Several interrelated molecular pathways are involved in the development of DR. Microvesicles (MVs) are cell membrane vesicles, which carry many biologic molecules, such as mRNAs, microRNAs, transcription factors, membrane lipids, membrane receptors, and other proteins. They may be involved in intercellular communication that can promote inflammation, angiogenesis, and coagulation. Recent studies have indicated that changes in the number and composition of MVs may reflect the pathologic conditions of DR. At present, MVs are well recognized as being involved in the pathophysiological conditions of tumors and cardio-metabolic diseases. However, the roles of MVs in DR have yet to be investigated. In this review, we provide an overview of DR-induced microvascular injury that is caused by MVs derived from endothelial and circulating cells, and discuss the possible mechanisms by which MVs can lead to endothelial dysfunction, coagulation and inflammation. In addition, the protective effects of preconditioned MVs and stem cell-derived MVs are also described . Understanding the involvement of MVs in the pathophysiological conditions of DR may provide insight into the disease mechanisms and may suggest novel therapeutic strategies for DR in the future.

Unaltered Angiogenesis-Regulating Activities of Platelets in Mild Type 2 Diabetes Mellitus despite a Marked Platelet Hyperreactivity

Type 2 diabetes mellitus (T2DM) is associated with platelet dysfunction and impaired angiogenesis. Aim of the study is to investigate if platelet dysfunction might hamper platelet angiogenic activities in T2DM patients. Sixteen T2DM patients and gender/age-matched non-diabetic controls were studied. Flow cytometry and endothelial colony forming cell (ECFC) tube formation on matrigel were used to assess platelet reactivity and angiogenic activity, respectively. Thrombin receptor PAR1-activating peptide (PAR1-AP) induced higher platelet P-selectin expression, and evoked more rapid and intense platelet annexin V binding in T2DM patients, seen as a more rapid increase of annexin V⁺ platelets (24.3±6.4% vs 12.6±3.8% in control at 2 min) and a higher elevation (30.9±5.1% vs 24.3±3.0% at 8 min). However, PAR1-AP and PAR4-AP induced similar releases of angiogenic regulators from platelets, and both stimuli evoked platelet release of platelet angiogenic regulators to similar extents in T2DM and control subjects. Thus, PAR1-stimulated platelet releasate (PAR1-PR) and PAR4-PR similarly enhanced capillary-like network/tube formation of ECFCs, and the enhancements did not differ between T2DM and control subjects. Direct supplementation of platelets to ECFCs at the ratio of 1:200 enhanced ECFC tube formation even more markedly, leading to approximately 100% increases of the total branch points of ECFC tube formation, for which the enhancements were also similar between patients and controls. In conclusion, platelets from T2DM subjects are hyperreactive. Platelet activation induced by high doses of PAR1-AP, however, results in similar releases of angiogenic regulators in mild T2DM and control subjects. Platelets from T2DM and control subjects also demonstrate similar enhancements on ECFC angiogenic activities.

Aspirin in the prevention of cardiovascular events in patients with diabetes

Diabetes imparts a substantial increased risk for cardiovascular disease-related mortality and morbidity. Because of this, current medical guidelines recommend prophylactic treatment with once-daily, low-dose aspirin (acetylsalicylic acid) for primary and secondary prevention of cardiovascular (CV) events in high-risk patients. However, only modest reductions in CV events and mortality have been observed with once-daily aspirin treatment in patients with diabetes, including patients with a previous CV event, perhaps because of disparity between aspirin pharmacokinetics and diabetes-related platelet abnormalities. Once-daily aspirin irreversibly inactivates platelets for only a short duration (acetylsalicylic acid half-life, approximately 15-20 minutes), after which time newly generated, active platelets enter the circulation and weaken aspirin's effect. Platelets from patients with diabetes are more reactive and are turned over more rapidly than platelets from normal individuals; the short inhibitory window provided by once-daily aspirin may therefore be insufficient to provide 24-h protection against CV events. Alternative conventional aspirin regimens (e.g. higher daily dose, twice-daily dosing, combination with clopidogrel) and newer formulations (e.g. 24-h, extended-release) have been proposed to overcome the apparent limited efficacy of conventional aspirin in patients with diabetes; however, tolerability concerns and limited clinical efficacy data need to be taken into account when considering the use of such regimens.

FoxO Transcription Factors and Regenerative Pathways in Diabetes Mellitus

Mammalian forkhead transcription factors of the O class (FoxO) are exciting targets under consideration for the development of new clinical entities to treat metabolic disorders and diabetes mellitus (DM). DM, a disorder that currently affects greater than 350 million individuals globally, can become a devastating disease that leads to cellular injury through oxidative stress pathways and affects multiple systems of the body. FoxO proteins can regulate insulin signaling, gluconeogenesis, insulin resistance, immune cell migration, and cell senescence. FoxO proteins also control cell fate through oxidative stress and pathways of autophagy and apoptosis that either lead to tissue regeneration or cell demise. Furthermore, FoxO signaling can be dependent upon signal transduction pathways that include silent mating type information regulation 2 homolog 1 (S. cerevisiae) (SIRT1), Wnt, and Wnt1 inducible signaling pathway protein 1 (WISP1). Cellular metabolic pathways driven by FoxO proteins are complex, can lead to variable clinical outcomes, and require in-depth analysis of the epigenetic and post-translation protein modifications that drive FoxO protein activation and degradation.

Analysis of platelet function and dysfunction

Although platelets act as central players of haemostasis only their cross-talk with other blood cells, plasma factors and the vascular compartment enables the formation of a stable thrombus. Multiple activation processes and complex signalling networks are responsible for appropriate platelet function. Thus, a variety of platelet function tests are available for platelet research and diagnosis of platelet dysfunction. However, universal platelet function tests that are sensitive to all platelet function defects do not exist and therefore diagnostic algorithms for suspected platelet function disorders are still recommended in clinical practice. Based on the current knowledge of human platelet activation this review evaluates point-of-care related screening tests in comparison with specific platelet function assays and focuses on their diagnostic utility in relation to severity of platelet dysfunction. Further, systems biology-based platelet function methods that integrate global and specific analysis of platelet vessel wall interaction (advanced flow chamber devices) and post-translational modifications (platelet proteomics) are presented and their diagnostic potential is addressed.

An association between anti-platelet drug use and reduced cancer prevalence in diabetic patients: results from the Vermont Diabetes Information System Study

Background

Diabetes is associated with an increased risk of several malignancies. Both diabetic patients and patients with cancer have an increase in platelet reactivity and platelet activation has recently emerged as a potential mediator of cancer progression. Drug therapies, such as aspirin, that reduce platelet reactivity reduce both cardiovascular and cancer risk.

Methods

We performed a cross-sectional analysis to assess the association between history of cancer and current anti-platelet drug use in a primary care population of adults with diabetes enrolled in the Vermont Diabetes Information System.

Results

Self-reported characteristics, medical history, and a complete medication list were recorded on 1007 diabetic adults. Fifty percent of diabetic patients used an anti-platelet drug. In unadjusted analysis, no association was seen between anti-platelet drug use and cancer history (OR = 0.93; P = .70). Platelet inhibitor use was associated with a decreased patient-reported history of malignancy in a multivariate logistic regression adjusted for age, sex, body mass index, comorbidity, and number of medications (OR = 0.66; CI 0.44-0.99; P = .045). Similar odds of association were seen in both males and females, and for aspirin and non-aspirin platelet inhibitor therapy.

Conclusions

Our data suggest an association between anti-platelet drug use and reduced cancer prevalence in patients with diabetes. Given the potentially large implications of our observations in the diabetic population, further studies are required to determine if this association is causal.

Effect of omega-3 fish oil on cardiovascular risk in diabetes

PURPOSE

Diabetes and cardiovascular disease are major public health concerns worldwide and are leading causes of morbidity and mortality. People with type 2 diabetes are at an increased risk for cardiovascular disease. Diet has a substantial affect on the progression of many diseases, including diabetes, cardiovascular disease, osteoporosis, and arthritis. Omega-3 polyunsaturated fatty acids (long-chain polyunsaturated fatty acids [LC-PUFA]) have long been attributed to the maintenance of health and may be of benefit in reducing cardiovascular risk. The purpose of this review is to investigate the possible roles of omega-3 in reducing cardiovascular risk in patients with diabetes.

METHODS

A literature search was conducted from the Medline, EBSCO, and EMBASE databases. Articles that addressed diabetes, cardiovascular disease, or omega-3 were included.

RESULTS

Reviews and studies reported an association with fish and omega-3 LC-PUFA consumption and decreased total cardiovascular mortality (approximately 15%-19%), along with decreased platelet activation and aggregation, improved lipid profiles, including reduction of triglycerides and very low-density lipoprotein (VLDL), decreased inflammation, and lowered blood pressure.

CONCLUSION

Diets higher in fish and omega-3 LC-PUFA may reduce cardiovascular risk in diabetes by inhibiting platelet aggregation, improving lipid profiles, and reducing cardiovascular mortality. Fish and omega-3 LC-PUFA can be recommended to people with diabetes and included into a diabetes management program.

Platelets of type 2 diabetic patients are characterized by high ATP content and low mitochondrial membrane potential

Platelet dysfunction plays a critical role in vascular complications of type 2 diabetes mellitus (T2DM). But the relationship between platelet hyperactivity and its energy metabolic process remains unclear. This study was designed to explore alterations of platelet mitochondrial ATP production and the possible mechanism. A total of 39 T2DM patients without macrovascular and microvascular complications and 32 normal controls were fasting sampled. Platelet ATP content was measured by a high performance liquid chromatograph (HPLC). The flow cytometry technique was adopted to evaluate mitochondrial membrane potential (DeltaPsim), the stored force for platelet ATP production. Consequently, T2DM patients exhibited obvious hyperglycemia, hyperlipidemia and hypertension, but normal platelet morphology. Platelet ATP content was significantly higher in T2DM (0.032 +/- 0.010 micromol/10(9) platelets versus 0.017 +/- 0.006 micromol/10(9) platelets, p < 0.001) than in the control group. Interestingly, DeltaPsim was markedly decreased in T2DM patients (0.79 +/- 0.18 versus 2.70 +/- 1.03, p < 0.001) compared with normal controls. For whole subjects, a stepwise regression showed that plasma glycated hemoglobin A1c (HbA1c) level positively correlated to platelet ATP content (beta = 0.552, 95% CI = 0.072-1.451), and fasting plasma glucose (FPG) level was negatively correlated to DeltaPsim (beta = -0.372, 95% CI = -0.471 to -0.089). These data support that hyperglycemia of T2DM promotes platelet mitochondria to generate more ATP, but decreases platelet mitochondrial potential. The discordance between them requires further researches to elucidate.