Diabetes and Thrombosis: A Central Role for Vascular Oxidative Stress

Platelet indices as predictors of poor glucoregulation in type 2 diabetes mellitus adults at Bishoftu General Hospital, Ethiopia

BACKGROUND

Diabetes is a chronic metabolic syndrome that has become a global public health problem with significant morbidity and mortality. It is a pro-inflammatory and pro-thrombotic condition characterized by increased platelet activation and alterations in platelet indices. However, the use of platelet indices as predictors of poor glucoregulation has not been fully evaluated in this context, and evidence for their role as predictors of poor glycemic status in diabetic patients is limited.

AIM

To evaluate platelet indices and determine their prognostic significance in relation to inadequate glucoregulation among individuals diagnosed with type 2 diabetes at Bishoftu General Hospital in Ethiopia, from June 15 to August 12, 2022.

METHODS

A comparative cross-sectional study was conducted in 261 participants including 174 individuals with type 2 diabetes mellitus (T2DM) and 87 non-diabetic controls. The systematic random sampling technique was used to select par-ticipants. Data were collected using structured questionnaires, physical measurements, checklists, and laboratory tests. Platelet parameters and fasting blood glucose levels were determined from blood samples using Sysmex-XN550 and CobasC311 analyzers, respectively. The hematology analyzer output was checked and participants were also screened for malaria parasites using a prepared blood smear. Collected data were entered into Epi-data version 3.1 and exported to SPSS version 25 for analysis. The χ² test, Mann-Whitney U test, Kruskal-Wallis test, post hoc test, Spearman correlation, and receiver operating characteristic curve were used for analysis. A P value < 0.05 was considered statistically significant.

RESULTS

The results of our study indicate that diabetic patients have significantly higher levels of platelet distribution width (PDW), mean platelet volume (MPV), platelet large cell ratio (PLCR), and plateletcrit (PCT) compared to healthy individuals (P < 0.001). Furthermore, these indices were found to be significantly elevated in individuals with poor glycemic control in T2DM compared to those with good glycemic control and healthy controls. We also observed significant correlations between these indices and various anthropometric and clinical variables. Our findings suggest that PDW, with a cut-off value of 15.75 fL and an area under the curve (AUC) of 0.803, MPV, with a cut-off value of 12.25 fL and an AUC of 0.774, PLCR, with a cut-off value of 36.3% and an AUC of 0.775, and PCT, with a cut-off value of 0.24% and an AUC of 0.761, can serve as predictors of poor glycemic control in patients with diabetes mellitus.

CONCLUSION

The observed correlation between diabetic patients and a significant increase in platelet indices has highlighted their potential as predictors of poor glycemic control in diabetes. Therefore, regular screening and profiling of platelet indices is recommended as part of the follow-up process for individuals with diabetes mellitus.

Risk factors for arterial catheter failure and complications during critical care hospitalisation: a secondary analysis of a multisite, randomised trial

OBJECTIVES

Arterial catheters (ACs) are critical for haemodynamic monitoring and blood sampling but are prone to complications. We investigated the incidence and risk factors of AC failure.

METHODS

Secondary analysis of a multi-centre randomised controlled trial (ACTRN 12610000505000). Analysis included a subset of adult intensive care unit patients with an AC. The primary outcome was all-cause device failure. Secondary outcomes were catheter associated bloodstream infection (CABSI), suspected CABSI, occlusion, thrombosis, accidental removal, pain, and line fracture. Risk factors associated with AC failure were investigated using Cox proportional hazards and competing-risk models.

RESULTS

Of 664 patients, 173 (26%) experienced AC failure (incidence rate [IR] 37/1000 catheter days). Suspected CABSI was the most common failure type (11%; IR 15.3/1000 catheter days), followed by occlusion (8%; IR 11.9/1,000 catheter days), and accidental removal (4%; IR 5.5/1000 catheter days). CABSI occurred in 16 (2%) patients. All-cause failure and occlusion were reduced with ultrasound-assisted insertion (failure: adjusted hazard ratio [HR] 0.43, 95% CI 0.25, 0.76; occlusion: sub-HR 0.11, 95% CI 0.03, 0.43). Increased age was associated with less AC failure (60-74 years HR 0.63, 95% CI 0.44 to 0.89; 75 + years HR 0.36, 95% CI 0.20, 0.64; referent 15-59 years). Females experienced more occlusion (adjusted sub-HR 2.53, 95% CI 1.49, 4.29), while patients with diabetes had less (SHR 0.15, 95% CI 0.04, 0.63). Suspected CABSI was associated with an abnormal insertion site appearance (SHR 2.71, 95% CI 1.48, 4.99).

CONCLUSIONS

AC failure is common with ultrasound-guided insertion associated with lower failure rates. Trial registration Australian New Zealand Clinical Trial Registry (ACTRN 12610000505000); date registered: 18 June 2010.

Influence of diabetes on the risk of deep vein thrombosis of patients after total knee arthroplasty: a meta-analysis

BACKGROUND

Previous studies evaluating the influence of diabetes on the risk of deep vein thrombosis (DVT) after total knee arthroplasty (TKA) showed inconsistent results. The aim of the study was to systematically evaluate the association between diabetes and DVT after TKA in a meta-analysis.

METHODS

An extensive search was conducted in PubMed, Embase, and Web of Science to identify relevant cohort studies. Random-effects models were employed to pool the results after taking account of the potential influence of heterogeneity.

RESULTS

Thirteen cohort studies involving 546,156 patients receiving TKA were included, with 71,110 (13.0%) diabetic patients before surgery and 1479 (2.1%) patients diagnosed as DVT after surgery. Overall, diabetes was associated with an increased risk of DVT after TKA (risk ratio [RR]: 1.43, 95% confidence interval [CI]: 1.12-1.84, p = 0.004; I2 = 44%). Sensitivity analysis limited to studies with chemoprophylaxis (RR: 1.96, 95% CI: 1.50-2.54), and studies with multivariate analysis (RR: 1.54, 95% CI: 1.12-2.11) showed consistent results. Subgroup analysis showed that diabetes was associated with higher risk of postoperative DVT in Asian countries (RR: 1.93, 95% CI: 1.49-2.52, p < 0.001; I2 = 1%) but not in Western countries (RR: 1.07, 95% CI: 0.86-1.34, p = 0.52; I2 = 0%; p for subgroup difference < 0.001).

CONCLUSION

Diabetes may be a risk factor for DVT after TKA, even with the chemoprophylaxis of anticoagulants. The association between diabetes and DVT after TKA may be more remarkable in patients from Asian countries.

Association between Relative Thrombocytosis and Microalbuminuria in Adults with Mild Fasting Hyperglycemia

An elevated platelet count may contribute to significant thrombotic events and pose a risk for diabetic microvascular complications. Albuminuria, one of the hallmarks of diabetes, is thought to be a risk factor for endothelial dysfunction. In this study, we investigated the association between relative thrombocytosis and an increased urine albumin-to-creatinine ratio in healthy adult participants. Using multivariate analyses on data from the Korea National Health and Nutrition Examination Survey V-VI, 12,525 eligible native Koreans aged ≥ 20 were categorized into platelet count quintiles by sex. The highest platelet count quintile included younger, more obese participants with elevated white blood cell counts, poor lipid profiles, and a better estimated glomerular filtration rate. Restricted cubic spline regression analysis revealed significant associations between platelet count and fasting blood glucose, glycated hemoglobin, and urine albumin-to-creatinine ratio. Adjusted logistic regression models indicated that heightened fasting blood glucose and platelet count were linked to risk of microalbuminuria (fasting blood glucose, odds ratio = 1.026, 95%CI = 1.011-1.042; platelet count, odds ratio = 1.004, 95%CI = 1.002-1.006). Particularly, an increased platelet count was notably associated with microalbuminuria progression in subjects with impaired fasting glucose. These findings suggest that an elevated platelet count, even below diagnostic thrombocytosis levels, independently correlates with an increased risk of vascular endothelial dysfunction in patients with impaired fasting glucose.

Targeting Cysteine Oxidation in Thrombotic Disorders

Oxidative stress increases the risk for clinically significant thrombotic events, yet the mechanisms by which oxidants become prothrombotic are unclear. In this review, we provide an overview of cysteine reactivity and oxidation. We then highlight recent findings on cysteine oxidation events in oxidative stress-related thrombosis. Special emphasis is on the signaling pathway induced by a platelet membrane protein, CD36, in dyslipidemia, and by protein disulfide isomerase (PDI), a member of the thiol oxidoreductase family of proteins. Antioxidative and chemical biology approaches to target cysteine are discussed. Lastly, the knowledge gaps in the field are highlighted as they relate to understanding how oxidative cysteine modification might be targeted to limit thrombosis.

Cysteine and methionine oxidation in thrombotic disorders

Thrombosis is the leading cause of death in many diseased conditions. Oxidative stress is characteristic of these conditions. Yet, the mechanisms through which oxidants become prothrombotic are unclear. Recent evidence suggests protein cysteine and methionine oxidation as prothrombotic regulators. These oxidative post-translational modifications occur on proteins that participate in the thrombotic process, including Src family kinases, protein disulfide isomerase, β2 glycoprotein I, von Willebrand factor, and fibrinogen. New chemical tools to identify oxidized cysteine and methionine proteins in thrombosis and hemostasis, including carbon nucleophiles for cysteine sulfenylation and oxaziridines for methionine, are critical to understanding why clots occur during oxidative stress. These mechanisms will identify alternative or novel therapeutic approaches to treat thrombotic disorders in diseased conditions.

The outcome of frailty in older people with diabetes as a function of glycaemic control and hypoglycaemic therapy: a review

INTRODUCTION

Frailty is an emerging and newly recognized complication of diabetes in older people. However, frailty is not thoroughly investigated in diabetes outcome studies.

AREAS COVERED

This manuscript reviews the effect of glycemic control and hypoglycemic therapy on the incidence of frailty in older people with diabetes.

EXPERT OPINION

Current studies show that both low glycemia and high glycemia are associated with frailty. However, most of the studies, especially low glycemia studies, are cross-sectional or retrospective, suggesting association, rather than causation, of frailty. In addition, frail patients in the low glycemia studies are characterized by lower body weight or lower body mass index (BMI), contrary to those in the high glycemia studies, who are either overweight or obese. This may suggest that frailty has a heterogeneous metabolic spectrum, starting with an anorexic malnourished (AM) phenotype at one end, which is associated with low glycemia and a sarcopenic obese (SO) phenotype on the other end, which is associated with high glycemia. The current little evidence suggests that poor glycemic control increases the risk of frailty, but there is a paucity of evidence to suggest that tight glycemic control would reduce the risk of incident frailty. Metformin is the only well-studied hypoglycemic agent, so far, to have a protective effect against frailty independent of glycemic control in the non-frail older people with diabetes. However, once frailty is developed, the choice of the best hypoglycemic agent for these patients will be affected by the metabolic phenotype of frailty. For example, sodium glucose transporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RA) are appropriate in the SO phenotype due to their weight losing properties, while insulin therapy may be considered early in the AM phenotype due to its anabolic and weight gaining benefits. Future studies are still required to further investigate the metabolic effects of frailty on older people with diabetes, determine the most appropriate HbA1c target, and explore the most suitable hypoglycemic agent in each metabolic phenotype of frailty.

Endothelial-dependent S-Sulfhydration of tissue factor pathway inhibitor regulates blood coagulation

Tissue factor pathway inhibitor (TFPI) is an important regulator of coagulation and a link between inflammation and thrombosis. Here we investigated whether endothelial cell-driven oxidative post-translational modifications could have an impact on TFPI activity. We focused on S-sulfhydration, which is a hydrogen sulfide-dependent post-translational modification that, in endothelial cells, is regulated by the enzyme cystathionine γ-lyase (CSE). The study made use of human primary endothelial cells and blood from healthy individuals or subjects with atherosclerosis as well as from mice lacking endothelial CSE. TFPI was S-sulfhydrated in endothelial cells from healthy individuals and mice, while the loss of endothelial CSE expression/activity reduced its modification. Non-S-sulfhydrated TFPI was no longer able to interact with factor Xa, which facilitated the activation of tissue factor. Similarly, non-S-sulfhydratable TFPI mutants bound less protein S, while supplementation with hydrogen sulfide donors, preserved TFPI activity. Phenotypically, loss of TFPI S-sulfhydration increased clot retraction, suggesting that this post-translational modification is a new endothelial cell-dependent mechanism that contributes to the regulation of blood coagulation.

Impacts of Diabetes Mellitus on Cardiovascular Outcomes and Differential Effects of Direct Oral Anticoagulants in Patients with Left Ventricular Thrombus

Background

The focus of this investigation into the impact of type 2 diabetes mellitus (T2DM) on left ventricular thrombus (LVT) is (a) the differences in LVT characteristics, (b) long-term clinical outcomes, and (c) differential effects of direct oral anticoagulants (DOAC) among patients with T2DM and without diabetes.

Methods

Patients with confirmed LVT from 2009 to 2021 were included. The primary endpoints were major adverse cardiac and cerebrovascular events (MACCE), composite of cardiovascular death, ischemic stroke, and acute myocardial infarction (AMI). The secondary endpoints were all-cause death and cardiovascular death. Multivariable competing-risk regression and cumulative incidence functions (CIF) were used to evaluate the adverse consequences.

Results

In total, 1675 patients were assessed initially. Follow-up data were available for 91.1% of the participants. Median follow-up was 3.8 years. This retrospective study ultimately comprised 1068 participants, of which 429 had T2DM. Significantly higher proportions of comorbidities were observed in the T2DM group. The location, morphology, and size of LVT were similar in the two groups. Multivariable analysis suggested a higher risk of MACCE among patients with T2DM. The difference in risk between the two groups after matching and weighting was not statistically significant. Among the whole sample (n = 638) or the just the non-diabetic patients with LVT and anticoagulation (n = 382), the incidence of MACCE did not differ between DOAC treatment and warfarin treatment. In the diabetic LVT population with anticoagulation (n = 256), DOAC treatment was associated with a significantly higher risk of MACCE than was warfarin treatment.

Conclusions

The location and morphology of LVT are similar in T2DM and non-diabetic patients. A higher risk of MACCE was found among patients with diabetes.

Effects of sub-chronic, in vivo administration of sigma-1 receptor ligands on platelet and aortic arachidonate cascade in streptozotocin-induced diabetic rats

Background

Diabetes mellitus is a chronic metabolic disorder which induces endothelial dysfunction and platelet activation. Eicosanoids produced from arachidonic acid regulate cellular and vascular functions. Sigma-1 receptors (S1R) are expressed in platelets and endothelial cells and S1R expression is protective in diabetes.

Objectives

Our aim was to examine the influence of sub-chronic, in vivo administered S1R ligands PRE-084, (S)-L1 (a new compound) and NE-100 on the ex vivo arachidonic acid metabolism of platelets and aorta in streptozotocin-induced diabetic rats.

Methods

The serum level of the S1R ligands was detected by LC-MS/MS before the ex vivo analysis. Sigma-1 receptor and cyclooxygenase gene expression in platelets were determined by RT-qPCR. The eicosanoid synthesis was examined with a radiolabelled arachidonic acid substrate and ELISA.

Results

One month after the onset of STZ-induced diabetes, in vehicle-treated, diabetic rat platelet TxB2 and aortic 6-k-PGF1α production dropped. Sub-chronic in vivo treatment of STZ-induced diabetes in rats for one week with PRE-084 enhanced vasoconstrictor and platelet aggregator and reduced vasodilator and anti-aggregator cyclooxygenase product formation. (S)-L1 reduced the synthesis of vasodilator and anti-aggregator cyclooxygenase metabolites and promoted the recovery of physiological platelet function in diabetic rats. The S1R antagonist NE-100 produced no significant changes in platelet arachidonic acid metabolism. (S)-L1 decreased the synthesis of vasoconstrictor and platelet aggregator cyclooxygenase metabolites, whereas NE-100 increased the quantity of aortic vasodilator and anti-aggregator cyclooxygenase products and promoted the recovery of diabetic endothelial dysfunction in the aorta. The novel S1R ligand, (S)-L1 had similar effects on eicosanoid synthesis in platelets as the agonist PRE-084 and in aortas as the antagonist NE-100.

Conclusions

S1R ligands regulate cellular functions and local blood circulation by influencing arachidonic acid metabolism. In diabetes mellitus, the cell-specific effects of S1R ligands have a compensatory role and aid in restoring physiological balance between the platelet and vessel.

Potential Therapeutic Properties of the Leaf of Cydonia Oblonga Mill. Based on Mineral and Organic Profiles

Leaf extract of Cydonia Oblonga Mill. is interesting for further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of green (October), yellow (November), and brown (December) quince leaves collected in the region of Pinhel, Portugal. Mineral analysis determined the measurements of the levels of several macro- and micro-elements. Organic analysis assessed the moisture content, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Mineral analysis was based on ICP-MS techniques, while the profiles of vitamin E and FA relied on HPLC-DAD-FLD and GC-FID techniques, respectively. Moisture content was determined through infrared hygrometry and TPC was determined by spectrophotometric methods. Regarding the mineral content, calcium, magnesium, and iron were the most abundant minerals. Concerning organic analysis, all leaf samples showed similar moisture content, while the TPC of gallic acid equivalents (GAE) and total vitamin E content, the most predominant of which was the α-tocopherol isomer, showed significant variations between green-brown and yellow leaves. FA composition in all leaf samples exhibited higher contents of SFA and PUFA than MUFA, with a predominance of palmitic and linolenic acids. Organic and inorganic analysis of quince leaves allow for the prediction of adequate physiological properties, mainly cardiovascular, pulmonary, and immunological defenses, which with our preliminary in silico studies suggest an excellent supplement to complementary therapy, including drastic pandemic situations.

SGLT2 Inhibition via Empagliflozin Improves Endothelial Function and Reduces Mitochondrial Oxidative Stress: Insights From Frail Hypertensive and Diabetic Patients

BACKGROUND

Frailty is a multidimensional condition often diagnosed in older adults with hypertension and diabetes, and both these conditions are associated with endothelial dysfunction and oxidative stress. We investigated the functional role of the SGLT2 (sodium glucose cotransporter 2) inhibitor empagliflozin in frail diabetic and hypertensive older adults.

METHODS

We studied the effects of empagliflozin in consecutive hypertensive and diabetic older patients with frailty presenting at the ASL (local health unit of the Italian Ministry of Health) of Avellino, Italy, from March 2021 to January 2022. Moreover, we performed in vitro experiments in human endothelial cells to measure cell viability, permeability, mitochondrial Ca²⁺, and oxidative stress.

RESULTS

We evaluated 407 patients; 325 frail elders with diabetes successfully completed the study. We propensity-score matched 75 patients treated with empagliflozin and 75 with no empagliflozin. We observed a correlation between glycemia and Montreal Cognitive Assessment (MoCA) score and between glycemia and 5-meter gait speed (5mGS). At 3-month follow-up, we detected a significant improvement in the MoCA score and in the 5mGS in patients receiving empagliflozin compared with non-treated subjects. Mechanistically, we demonstrate that empagliflozin significantly reduces mitochondrial Ca²⁺ overload and reactive oxygen species production triggered by high glucose in human endothelial cells, attenuates cellular permeability, and improves cell viability in response to oxidative stress.

CONCLUSIONS

Taken together, our data indicate that empagliflozin reduces frailty in diabetic and hypertensive patients, most likely by decreasing the mitochondrial generation of reactive oxygen species in endothelial cells.

Redox Mechanisms of Platelet Activation in Aging

Aging is intrinsically linked with physiologic decline and is a major risk factor for a broad range of diseases. The deleterious effects of advancing age on the vascular system are evidenced by the high incidence and prevalence of cardiovascular disease in the elderly. Reactive oxygen species are critical mediators of normal vascular physiology and have been shown to gradually increase in the vasculature with age. There is a growing appreciation for the complexity of oxidant and antioxidant systems at the cellular and molecular levels, and accumulating evidence indicates a causal association between oxidative stress and age-related vascular disease. Herein, we review the current understanding of mechanistic links between oxidative stress and thrombotic vascular disease and the changes that occur with aging. While several vascular cells are key contributors, we focus on oxidative changes that occur in platelets and their mediation in disease progression. Additionally, we discuss the impact of comorbid conditions (i.e., diabetes, atherosclerosis, obesity, cancer, etc.) that have been associated with platelet redox dysregulation and vascular disease pathogenesis. As we continue to unravel the fundamental redox mechanisms of the vascular system, we will be able to develop more targeted therapeutic strategies for the prevention and management of age-associated vascular disease.