Comparison of levels of inflammatory markers and hemostatic factors in the patients with and without peripheral arterial disease

Interpretable machine learning models for detecting peripheral neuropathy and lower extremity arterial disease in diabetics: an analysis of critical shared and unique risk factors

BACKGROUND

Diabetic peripheral neuropathy (DPN) and lower extremity arterial disease (LEAD) are significant contributors to diabetic foot ulcers (DFUs), which severely affect patients' quality of life. This study aimed to develop machine learning (ML) predictive models for DPN and LEAD and to identify both shared and distinct risk factors.

METHODS

This retrospective study included 479 diabetic inpatients, of whom 215 were diagnosed with DPN and 69 with LEAD. Clinical data and laboratory results were collected for each patient. Feature selection was performed using three methods: mutual information (MI), random forest recursive feature elimination (RF-RFE), and the Boruta algorithm to identify the most important features. Predictive models were developed using logistic regression (LR), random forest (RF), and eXtreme Gradient Boosting (XGBoost), with particle swarm optimization (PSO) used to optimize their hyperparameters. The SHapley Additive exPlanation (SHAP) method was applied to determine the importance of risk factors in the top-performing models.

RESULTS

For diagnosing DPN, the XGBoost model was most effective, achieving a recall of 83.7%, specificity of 86.8%, accuracy of 85.4%, and an F1 score of 83.7%. On the other hand, the RF model excelled in diagnosing LEAD, with a recall of 85.7%, specificity of 92.9%, accuracy of 91.9%, and an F1 score of 82.8%. SHAP analysis revealed top five critical risk factors shared by DPN and LEAD, including increased urinary albumin-to-creatinine ratio (UACR), glycosylated hemoglobin (HbA1c), serum creatinine (Scr), older age, and carotid stenosis. Additionally, distinct risk factors were pinpointed: decreased serum albumin and lower lymphocyte count were linked to DPN, while elevated neutrophil-to-lymphocyte ratio (NLR) and higher D-dimer levels were associated with LEAD.

CONCLUSIONS

This study demonstrated the effectiveness of ML models in predicting DPN and LEAD in diabetic patients and identified significant risk factors. Focusing on shared risk factors may greatly reduce the prevalence of both conditions, thereby mitigating the risk of developing DFUs.

An evaluation of inflammatory and endothelial dysfunction markers as determinants of peripheral arterial disease in those with diabetes mellitus

The most serious long-term effects of diabetes is peripheral artery disease (PAD) which increases the chance of developing diabetic foot ulcers, gangrene and even lower limb amputation. The clinical manifestations of PAD which are typically not revealed until symptoms like intermittent claudication, rest pain and ischemic gangrene develop, are not present in majority of diabetes mellitus patients with PAD due to diabetic peripheral neuropathy. Therefore, current study is aimed to evaluate the inflammatory and endothelial dysfunction markers with their correlation to biomarkers that can help for in-time diagnosis and efficient prognosis of developing diabetes-associated PAD. Enzyme-linked immunosorbent assay was used to evaluate the interlukin-6, interlukin-8, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) in PAD with diabetes group, diabetic group and healthy individual group while biomarkers were measured by kit method. It was observed that serum IL-6, IL-8, ICAM and VCAM levels in type II diabetes mellitus (T2DM) with PAD patients were increased significantly (85.93, 597.08, 94.80 and 80.66) as compared to T2DM patients (59.52, 231.34, 56.88 and 50.19) and healthy individuals (4.81, 16.93, 5.55 and 5.16). The overall means for the parameters, IL-6, IL-8, ICAM, VCAM, urea, S/creatinine, CK-MB, AST, ALT, cholesterol, triglyceride, HDL, LDL, PT, aPTT, INR, HbA1C, and CRP within all groups were significantly (P < 0.05) different from each other. Therefore, it was concluded that the change in IL-6, IL-8, ICAM and VCAM can serve as an accurate diagnostic indicator and successful treatment.

Predictive Value of the Naples Prognostic Score on Long-Term Outcomes in Patients with Peripheral Artery Disease Revascularized via Percutaneous Intervention

BACKGROUND

Lower extremity peripheral artery disease (PAD) is the third most common clinical manifestation of atherosclerosis after coronary artery disease and stroke. Despite successful endovascular treatment (EVT), mortality and morbidity rates still remain higher in patients with PAD. Naples prognostic score (NPS) is a novel scoring system, reflects the patient's nutritional and immunological statuses as well as systemic inflammatory responses. In this study, we aimed to investigate the relationship between NPS and long-term outcomes in patients with PAD.

METHODS

The population of this retrospective study consisted of 629 PAD patients who underwent EVT at Kafkas University Hospital between 2020 and 2023. For each patient, the NPS was calculated and then patients were divided into 3 groups based on their NPS. The primary end point of the study was the rate of major adverse cardiovascular (MACEs) and limb events (MALEs), that is, all-cause death or development of critical limb ischemia with consequent amputation.

RESULTS

Of a total of 629 patients, 62 were classified into group 0 (NPS 0), 315 into group 1 (NPS 1 or 2), and 252 into group 2 (NPS 3 or 4). The distribution of patients' baseline characteristics, angiographic features and MACEs and MALEs according to the NPS groups was analyzed. Significant adverse outcomes differences were observed among the 3 groups (P < 0.001). Multivariate logistic regression analysis revealed that age, diabetes mellitus, chronic kidney disease, lowest preprocedure ankle-brachial index, left ventricular ejection fraction and NPS (hazard ratio 1.916, 95% confidence interval [CI] 1.530-2.398, P < 0.001) were independent predictors of MACE whereas diabetes mellitus, presence of previous PAD, hemoglobin level, in-hospital acute thrombotic occlusion and NPS (odds ratio 1.963, 95% CI 1.489-2.588, P < 0.001) were independent predictors of MALE.

CONCLUSIONS

The inflammatory and nutritional state reflected by NPS levels was strongly associated with all-cause mortality and amputation after EVT in patients with PAD. Furthermore, NPS was found to be an independent predictor of these clinical outcomes.

The Role of the Coagulation System in Peripheral Arterial Disease: Interactions with the Arterial Wall and Its Vascular Microenvironment and Implications for Rational Therapies

Peripheral artery disease (PAD) is a clinical manifestation of atherosclerotic disease with a large-scale impact on the economy and global health. Despite the role played by platelets in the process of atherogenesis being well recognized, evidence has been increasing on the contribution of the coagulation system to the atherosclerosis formation and PAD development, with important repercussions for the therapeutic approach. Histopathological analysis and some clinical studies conducted on atherosclerotic plaques testify to the existence of different types of plaques. Likely, the role of coagulation in each specific type of plaque can be an important determinant in the histopathological composition of atherosclerosis and in its future stability. In this review, we analyze the molecular contribution of inflammation and the coagulation system on PAD pathogenesis, focusing on molecular similarities and differences between atherogenesis in PAD and coronary artery disease (CAD) and discussing the possible implications for current therapeutic strategies and future perspectives accounting for molecular inflammatory and coagulation targets. Understanding the role of cross-talking between coagulation and inflammation in atherosclerosis genesis and progression could help in choosing the right patients for future dual pathway inhibition strategies, where an antiplatelet agent is combined with an anticoagulant, whose role, despite pathophysiological premises and trials' results, is still under debate.

Circulating Biomarkers in Lower Extremity Artery Disease

Lower extremity artery disease (LEAD), a chronic condition with disturbed lower extremity circulation due to narrowing of the arteries, is predominantly caused by atherosclerosis and is associated with the presence of cardiovascular risk factors and an increased risk of cardiovascular events. LEAD is prevalent among older individuals and predicted to rise with the ageing population. In progressive disease, the patient experiences symptoms of ischaemia when walking and, in advanced critical limb-threatening ischaemia, even at rest. However, LEAD is asymptomatic in most patients, delaying diagnosis and treatment. In this setting, circulating biomarkers may facilitate earlier diagnosis in selected individuals. This review provides a broad overview of the circulating biomarkers investigated to date in relation to LEAD and discusses their usefulness in clinical practice.

The Role of Circulating Biomarkers in Peripheral Arterial Disease

Peripheral arterial disease (PAD) of the lower extremities is a chronic illness predominantly of atherosclerotic aetiology, associated to traditional cardiovascular (CV) risk factors. It is one of the most prevalent CV conditions worldwide in subjects >65 years, estimated to increase greatly with the aging of the population, becoming a severe socioeconomic problem in the future. The narrowing and thrombotic occlusion of the lower limb arteries impairs the walking function as the disease progresses, increasing the risk of CV events (myocardial infarction and stroke), amputation and death. Despite its poor prognosis, PAD patients are scarcely identified until the disease is advanced, highlighting the need for reliable biomarkers for PAD patient stratification, that might also contribute to define more personalized medical treatments. In this review, we will discuss the usefulness of inflammatory molecules, matrix metalloproteinases (MMPs), and cardiac damage markers, as well as novel components of the liquid biopsy, extracellular vesicles (EVs), and non-coding RNAs for lower limb PAD identification, stratification, and outcome assessment. We will also explore the potential of machine learning methods to build prediction models to refine PAD assessment. In this line, the usefulness of multimarker approaches to evaluate this complex multifactorial disease will be also discussed.

Outcomes of Lower Extremity Endovascular Revascularization: Potential Predictors and Prevention Strategies

Peripheral artery disease (PAD) is a manifestation of atherosclerosis, which may affect arteries of the lower extremities. The most dangerous PAD complication is chronic limb-threatening ischemia (CLTI). Without revascularization, CLTI often causes limb loss. However, neither open surgical revascularization nor endovascular treatment (EVT) ensure long-term success and freedom from restenosis and revascularization failure. In recent years, EVT has gained growing acceptance among all vascular specialties, becoming the primary approach of revascularization in patients with CLTI. In clinical practice, different clinical outcomes after EVT in patients with similar comorbidities undergoing the same procedure (in terms of revascularization technique and localization of the disease) cause unsolved issues that need to be addressed. Nowadays, risk management of revascularization failure is one of the major challenges in the vascular field. The aim of this literature review is to identify potential predictors for lower extremity endovascular revascularization outcomes and possible prevention strategies.

Biomarker Utility for Peripheral Artery Disease Diagnosis in Real Clinical Practice: A Prospective Study

Peripheral arterial disease (PAD) is a common manifestation of generalized atherosclerosis, which affects more than 200 million patients worldwide. Currently, there is no ideal biomarker for PAD risk stratification and diagnosis. The goal of this research was to investigate the levels of inflammation biomarkers and cystatin C and to explore their utility for the diagnosis of PAD. The study included 296 participants, distributed in two groups: 216 patients diagnosed with PAD and 80 patients without PAD as controls. All studied biomarker levels (C-reactive protein, CRP; fibrinogen; erythrocyte sedimentation rate, ESR; neopterin; beta 2-microglobulin, B2-MG; and cystatin C) were significantly higher in the PAD group and indirectly correlated with the ankle-brachial index (ABI). The final logistic regression model included an association of neopterin, fibrinogen, and cystatin C as the most efficient markers for the prediction of PAD diagnosis. When comparing the area under the curve (AUC) for all biomarkers, the value for neopterin was significantly higher than those of all the other analyzed biomarkers. In agreement with previous studies, this research shows that markers such as fibrinogen, CRP, ESR, B2-MG, and cystatin C have significant value for the diagnosis of PAD, and also clearly underlines the accuracy of neopterin as a leading biomarker in PAD prediction.

Serum high mobility group box-1 and osteoprotegerin levels are associated with peripheral arterial disease and critical limb ischemia in type 2 diabetic subjects

BACKGROUND

High mobility group box-1 (HMGB-1) is a nuclear protein also acting as inflammatory mediator, whilst osteoprotegerin (OPG), member of tumor necrosis factor receptor superfamily, is indicated as marker of vascular calcification. Peripheral artery disease (PAD) and type 2 diabetes (T2D) are clinical conditions characterized by elevated serum inflammatory markers and vascular calcification enhancement. The aim of this study was to investigate the potential role of HMGB-1, OPG and several inflammatory mediators such as C-reactive protein (HsCRP), tumor necrosis factor-alpha and interleukin-6 (IL-6) on the presence and severity of peripheral artery disease in patients with T2D.

METHODS

In this retrospective observational study, we have analyzed HMGB-1, OPG and inflammatory cytokines serum levels in 1393 type 2 diabetic patients with PAD and without PAD (WPAD).

RESULTS

HMGB-1 (7.89 ± 15.23 ng/mL), OPG (6.54 ± 7.76 pmol/L), HsCRP (15.6 ± 14.4 mg/L) and IL-6 (56.1 ± 28.6 pg/mL) serum levels were significantly higher in patients with PAD than in those WPAD (3.02 ± 8.12 ng/mL, P ˂ 0.001; 2.98 ± 2.01 pmol/L, P < 0.001; 7.05 ± 4.4 mg/L, P < 0.001; 37.5 ± 20.2 pg/mL, P < 0.001 respectively). Moreover HMGB-1 (P < 0.001), OPG (P < 0.001), HsCRP (P < 0.001) and IL-6 (P < 0.001) serum levels were positively correlated with clinical severity of PAD. HMGB-1 (adjusted OR 12.32; 95% CI 3.56-23.54, P = 0.023) and OPG (adjusted OR 3.53; 95% CI 1.54-6.15, P = 0.019) resulted independent determinants of PAD in patients with T2D after adjusting for the conventional cardiovascular risk factor and established inflammatory mediators.

CONCLUSIONS

In T2D patients HMGB-1 and OPG serum levels are higher in patients affected by PAD and independently associated with its occurrence and clinical severity.

Biomarkers and Genetics in Peripheral Artery Disease

BACKGROUND

Peripheral artery disease (PAD) is highly prevalent and there is considerable diversity in the initial clinical manifestation and disease progression among individuals. Currently, there is no ideal biomarker to screen for PAD, to risk stratify patients with PAD, or to monitor therapeutic response to revascularization procedures. Advances in human genetics have markedly enhanced the ability to develop novel diagnostic and therapeutic approaches across a host of human diseases, but such developments in the field of PAD are lagging.

CONTENT

In this article, we will discuss the epidemiology, traditional risk factors for, and clinical presentations of PAD. We will discuss the possible role of genetic factors and gene-environment interactions in the development and/or progression of PAD. We will further explore future avenues through which genetic advances can be used to better our understanding of the pathophysiology of PAD and potentially find newer therapeutic targets. We will discuss the potential role of biomarkers in identifying patients at risk for PAD and for risk stratifying patients with PAD, and novel approaches to identification of reliable biomarkers in PAD.

SUMMARY

The exponential growth of genetic tools and newer technologies provides opportunities to investigate and identify newer pathways in the development and progression of PAD, and thereby in the identification of newer biomarkers and therapies.

Plasma Levels of Inflammatory Biomarkers in Peripheral Arterial Disease: Results of a Cohort Study

Previous research analyzed the level of plasma inflammatory markers in patients with coronary disease, but very few studies have evaluated these markers in patients with peripheral arterial disease (PAD). The objective of this study was to investigate the plasma levels of inflammatory markers in patients with PAD and in healthy controls. The following plasma levels of biomarkers were measured in 80 patients with PAD (mean age 68 ± 5 years) and in 72 healthy participants (mean age 67 ± 6 years): interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), L-selectin (LS), neopterin (N), P-selectin (PS), E-selectin (ES), vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and matrix metalloproteinase 2 (MMP-2), and 9 (MMP-9). Significantly higher levels of IL-6 (P < .001), TNF-α (P < .0001), ES (P < .0001), LS (P < .0001), PS (P < .0001), ICAM-1 (P < .001), VCAM-1 (P < .001), N (P < .001), MMP-2 (P < .001), and MMP-9 (P < .005) were found in the patients with PAD. Patients with PAD show a inflammation marker profile different from that of control participants. Reducing the high plasma levels of inflammatory markers could be a new therapeutic approach both for the prevention and the treatment of PAD.

Serum D-dimer Levels Are Proportionally Associated with Left Atrial Enlargement in Patients with an Acute Ischemic Stroke due to Non-valvular Atrial Fibrillation

Objective Left atrial enlargement (LAE) may predispose individuals to blood stasis in atrial fibrillation (AF), and thus play a crucial role in thrombogenesis. The D-dimer level is one of the surrogate markers for a hypercoagulable state and reflects thrombus formation in AF. Since the D-dimer level reflects hypercoagulability as well as thrombus and fibrin burdens, LAE could be associated with a D-dimer elevation. However, no studies have explored this association or which factors contribute to increases in the D-dimer levels in patients with AF. Therefore, we assessed whether the serum D-dimer levels are related to the left atrial volume index (LAVI) or other vascular risk factors and also evaluated the association between the D-dimer levels and the initial stroke severity. Methods Ninety-eight consecutive patients with an acute ischemic stroke and non-valvular AF (NVAF) who were anticoagulation-naïve were enrolled, and all patients were stratified into moderate-to-severe and mild neurologic deficit groups using the National Institutes of Health Stroke Scale on admission. The association between the initial serum D-dimer levels and the LAVI was evaluated in all enrolled patients, and the serum D-dimer levels were compared between the two groups. Results The patients were classified into two groups according to the severity of the neurologic deficit. In a partial correlation coefficient analysis adjusted for confounding factors, an increase in the initial serum D-dimer levels was significantly associated with LAVI (r=0.286; p=0.027). A linear regression analysis showed that a history of peripheral artery disease was the factor most strongly associated with the serum D-dimer level (t=3.90, p<0.001), followed by LAVI (t=2.37, p=0.021) and a history of congestive heart failure (t=2.16, p=0.035). The D-dimer levels were higher in the moderate-to-severe neurologic deficit group than in the mild deficit group, but this difference was not statistically significant (4.5±7.1 vs. 1.6±2.6 mg/L, p=0.068). Conclusion The serum D-dimer levels were significantly associated with LAE in anticoagulation-naïve patients with an acute ischemic stroke and NVAF.

D-Dimer elevation and adverse outcomes

d-Dimer is a biomarker of fibrin formation and degradation. While a d-dimer within normal limits is used to rule out the diagnosis of deep venous thrombosis and pulmonary embolism among patients with a low clinical probability of venous thromboembolism (VTE), the prognostic association of an elevated d-dimer with adverse outcomes has received far less emphasis. An elevated d-dimer is independently associated with an increased risk for incident VTE, recurrent VTE, and mortality. An elevated d-dimer is an independent correlate of increased mortality and subsequent VTE across a broad variety of disease states. Therefore, medically ill subjects in whom the d-dimer is elevated constitute a high risk subgroup in which the prospective evaluation of the efficacy and safety of antithrombotic therapy is warranted.

Comparison of serum amyloid A protein and C-reactive protein levels as inflammatory markers in periodontitis

PURPOSE

The purpose of this study was to compare serum amyloid A (SAA) protein levels with high-sensitive C-reactive protein (hs-CRP) levels as markers of systemic inflammation in patients with chronic periodontitis. The association of serum titers of antibodies to periodontal microbiota and SAA/hs-CRP levels in periodontitis patients was also studied.

METHODS

A total of 110 individuals were included in this study. Patients were assessed for levels of hs-CRP and SAA. Nonfasting blood samples were collected from participants at the time of clinical examination. The diagnosis of adipose tissue disorders was made according to previously defined criteria. To determine SAA levels, a sandwich enzyme-linked immunosorbent assay was utilized. Paper points were transferred to a sterile tube to obtain a pool of samples for polymerase chain reaction processing and the identification of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia. The serum level of IgG1 and IgG2 antibodies to P. gingivalis, A. actinomycetemcomitans, and T. forsythia was also determined.

RESULTS

SAA and hs-CRP levels were higher in periodontitis patients than in controls (P<0.05). In bivariate analysis, high levels of hs-CRP (>3 mg/L) and SAA (>10 mg/L) were significantly associated with chronic periodontitis (P=0.004). The Spearman correlation analysis between acute-phase proteins showed that SAA positively correlated with hs-CRP (r=0.218, P=0.02). In the adjusted model, chronic periodontitis was associated with high levels of SAA (odds ratio [OR], 5.5; 95% confidence interval [CI], 1.6-18.2; P=0.005) and elevated hs-CRP levels (OR, 6.1, 95% CI, 1.6-23.6; P=0.008). Increased levels of serum IgG2 antibodies to P. gingivalis were associated with high levels of SAA (OR, 3.6; 95% CI, 1.4-8.5; P=0.005) and high concentrations of hs-CRP (OR, 4.3; 95% CI, 1.9-9.8; P<0.001).

CONCLUSIONS

SAA and hs-CRP concentrations in patients with chronic periodontitis are comparably elevated. High serum titers of antibodies to P. gingivalis and the presence of periodontal disease are independently related to high SAA and hs-CRP levels.

Neopterin: a potential marker in chronic peripheral arterial disease

Neopterin is a marker of macrophage activation that has exhibited high plasma levels in atherosclerotic diseases including coronary heart disease and critical limb ischemia. The role of neopterin in chronic peripheral arterial disease (PAD) has yet to be elucidated. In the present study, neopterin (Ν) serum concentrations were analyzed in asymptomatic (AsP) and symptomatic (SyP) patients with PAD as well as controls (C). In total 120 subjects, 40 AsP [ankle brachial index (ABI) ≤0.90], 40 SyP (ABI ≤0.90 plus pain in legs) and 40 controls (ABI >0.9) were enrolled. The results of the present study showed that neopterin plasma levels were statistically different among the groups. These findings demonstrated that activation of N‑mediated monocyte‑macrophage, was also observed in chronic PAD.

The correlation between the cardio-ankle vascular index (CAVI) and serum amyloid A in asymptomatic Japanese subjects

Chronic inflammation has received a great deal of attention due to the role it plays in cardiovascular disease (CVD). The cardio-ankle vascular index (CAVI) has recently been developed to evaluate arterial stiffness. This index is independent of blood pressure at the time that it is measured, making it a better measure for clinical studies on the prevention of CVD. Information on the association of serum amyloid A (SAA) with arterial stiffness in relatively healthy subjects is still scarce. The aim of the present study was to investigate the potential correlation between SAA and CAVI in asymptomatic Japanese subjects. In addition to SAA and CAVI, data on smoking status, body mass index, blood pressure, and serum/plasma biochemical indices such as glucose and total cholesterol were collected in 387 nonmedicated and CVD-free adult subjects during a health check examination (male/female 191/196, mean age 61.8 years). Among them, a randomly selected subgroup of 256 subjects (male/female 133/123, mean age 62.4 years) had a full dataset, including low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, and hemoglobin A1c. Among the whole population, CAVI levels were significantly higher in males than in females [mean 8.5 ± (SD 1.1) vs. 8.2 ± 1.1, p < 0.05], while SAA levels were slightly but nonsignificantly higher in females than in males [median 6.4 (interquartile range 4.0-9.3) μg/mL vs. 5.1 (3.5-8.4)]. In a multiple linear regression analysis, CAVI was weakly but significantly, independently, and positively correlated with SAA (β-coefficient 0.200, p < 0.01). The results of the same analyses for the randomly selected subgroup were relatively similar to the findings for the whole population. SAA may be a positive inflammatory factor associated with arterial stiffness, and the clinical relevance and the biological mechanism for this relationship should be established in future studies.

Novel markers of peripheral arterial disease

Peripheral arterial disease (PAD), a relatively common manifestation of atherosclerotic vascular disease, is associated with significant morbidity and mortality. Although conventional risk factors contribute to the onset and progression of PAD, the role of 'novel' biomarkers in pathways of inflammation, thrombosis, lipoprotein metabolism, and oxidative stress in determining susceptibility to PAD is being increasingly recognized. Validation of novel risk factors for PAD may allow earlier detection, an improved understanding of disease etiology and progression, and the development of new therapies. In this review, we discuss available evidence for associations between novel circulating markers and several aspects of PAD including disease susceptibility, progression, functional limitation, and adverse outcomes.

Hypercoagulability markers in patients with peripheral arterial disease: association to ankle-brachial index

Peripheral arterial disease is diagnosed by measuring the ankle-brachial index. Values lower than 0.90 define the disease being usually related to its severity. Patients with peripheral arterial disease may show a hypercoagulability state. The aim of this study was to assess hemostatic variables and to correlate them with the presence of peripheral arterial disease and its severity as assessed by ankle-brachial index values. Plasma levels of D dimer, plasminogen, prothrombin fragment 1+2, plasminogen activator inhibitor and thrombomodulin were measured in 36 patients with peripheral arterial disease (group 1) and 30 without disease (group 2). Significant differences for D dimer, plasminogen, prothrombin fragment 1+2 and plasminogen activator inhibitor type 1 between the 2 groups were found (P<0.05). Significant and inverse correlations were also observed (Pearson correlation, P<0.05) between ankle-brachial index values and levels of both plasminogen and plasminogen activator inhibitor type 1. Although there was no significant correlation between ankle-brachial index and levels of D dimer, higher D dimer values were observed in patients with lower ankle-brachial index values. The results confirm a trend to hypercoagulability and hypofibrinolysis in patients with peripheral arterial disease. Increased levels of plasminogen activator inhibitor type 1 seem to be associated with the severity of the disease, considering the inverse correlation between this inhibitor and ankle-brachial index.

D-dimers, thrombin-antithrombin complexes, and risk factors for thromboembolism in hospitalized patient

INTRODUCTION

There is lack of data about the correlation between hemostatic markers and the clinical and biological risk factors (RFs) for venous thromboembolism (VTE) in medical inpatients without suspicion of acute VTE.

MATERIAL AND METHODS

To evaluate the coagulation activation status in patients with current known RFs for VTE, the authors measured 2 markers of hypercoagulability, thrombin antithrombin (TAT) complexes and D-dimers, at day 1 in 165 patients hospitalized in internal medicine wards without suspected acute VTE. All known RFs for VTE were systematically assessed at admission and classified in a chronological way as permanent or transient.

RESULTS

Surprisingly, TAT values followed a multimodal distribution. D-dimers showed a normal distribution after a logarithmic transformation (P = .34, Shapiro-Wilk test). Interestingly, a significant progression in D-dimer levels was found according to the chronological classification of RFs. D-dimer variations on multivariate analysis (not applicable for TAT because of the multimodal distribution) correlated independently with a recent inability to walk and an increase in C reactive protein level more than 10 mg/L.

CONCLUSIONS

(a) this study is the first to describe the variations of hypercoagulability markers according to a systematic screening of RFs for VTE in inpatients without suspicion of acute VTE, (b) TAT appeared as a less relevant marker of hypercoagulability than D-dimers in internal medicine inpatients, (d) the chronological classification of RFs identified clearly groups at risk for the prethrombotic state, and (d) an increased hypercoagulability state was demonstrated in patients with an association between a recent immobility and increased inflammatory markers.

The role of fibrinogen and fibrinolysis in peripheral arterial disease

Peripheral arterial disease (PAD) is associated with high rates of cerebrovascular and cardiovascular events; PAD is a marker of systemic atherosclerosis. As a result, standard therapy for all PAD patients should be directed at both peripheral and systemic atherosclerosis. Modification of established risk factors in the form of smoking cessation, correcting hypertension, optimizing diabetic control and normalizing lipids is essential. Furthermore, novel risk factors have emerged including fibrinogen and other hemostatic factors. Fibrinogen is a coagulation factor and a marker of the acute phase response (inflammation), a platelet activator, a major determinant of plasma viscosity and a component of the atherosclerotic plaque. Fibrinogen appears not only to predict the severity of PAD, but also serves as a marker for future development of PAD. Whether reducing the levels of fibrinogen and other coagulation factors will decrease the incidence and progression of PAD remains to be resolved. This review summarizes the role of fibrinogen in the pathogenesis of PAD and its association with other hemostatic factors. The role of fibrinolysis in patients with PAD is also considered.

A rational connection of inflammation with peripheral arterial disease

Peripheral arterial disease (PAD) includes a wide range of manifestations in the lower limb, from asymptomatic to symptomatic disease ranging from intermittent claudication to critical limb ischemia, with ulcers, rest pain, or gangrene. It is manifestation of generalized atherosclerosis and this is clearly shown by the high prevalence of coexistence coronary and cerebral arterial disease in these patients. The cumulative findings on molecular and cellular biology have dramatically changed our concept of atherosclerotic disease. Recently, it has become clear that inflammation is fundamental to the process of atherosclerosis. Although the relation between inflammation and PAD is not well characterized, the emerging data demonstrated that PAD is a common manifestation of atherosclerosis that is associated with a systemic inflammation. The most important risk factors for PAD are similar to those of atherosclerotic disease elsewhere: age, male sex, diabetes mellitus, smoking, hypertension, hyperlipidemia, and hereditary factors. Serum levels of inflammatory markers, especially after exercise, have been found to be higher in patients with PAD than in controls, and associated with prognosis as well as restenosis in patients with PAD after revascularization. In the general United States adult population, inflammation is independently associated with PAD in a cross-sectional, nationally large representative sample. All of those evidences indicate that PAD is one aspect of atherosclerosis, a disease rationally connects with inflammation, which may further change our preventive and therapeutic strategies.

Inflammation, obesity and cardiovascular function in African and Caucasian women from South Africa: the POWIRS study

The integrated relationship between inflammation, obesity and cardiovascular disease is currently a subject of much research interest. These specific relationships, however, have not been studied in-depth in South African population groups in order to determine the role of ethnicity. It is known that Africans, compared to Caucasians, suffer from a high prevalence of hypertension. It was therefore hypothesized that the levels of inflammatory markers (high-sensitivity C-reactive protein (hsCRP), fibrinogen and leptin) are higher in Africans compared to Caucasians and are notably associated with cardiovascular dysfunction in Africans. Apparently healthy African (N=102) and Caucasian (N=115) women, matched for age and body mass index (BMI), were recruited. Leptin, hsCRP, fibrinogen and lipid levels, waist circumference (WC), BMI, systolic and diastolic blood pressure, cardiac output (CO), total peripheral resistance (TPR) and Windkessel compliance were measured. Results showed that the levels of leptin, hsCRP and fibrinogen were significantly higher (P<0.05) in the African women. The inflammatory markers correlated strongly with cardiovascular parameters, age and obesity (BMI, WC) in both groups, but after adjusting for age and obesity, none of the correlations were significant anymore. Multiple regression analyses (with leptin, hsCRP or fibrinogen as dependent variable) showed that only leptin levels of African women were explained by cardiovascular parameters (BP, TPR and CO). In conclusion, even though African women had significantly higher leptin, hsCRP, fibrinogen and blood pressure levels than Caucasian women, no cardiovascular parameters explained the variation in the inflammatory markers (except for leptin levels of African women).