Plasma osteoprotegerin is related to carotid and peripheral arterial disease, but not to myocardial ischemia in type 2 diabetes mellitus

Current Medical Therapy and Revascularization in Peripheral Artery Disease of the Lower Limbs: Impacts on Subclinical Chronic Inflammation

Peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CeVD) are characterized by atherosclerosis and inflammation as their underlying mechanisms. This paper aims to conduct a literature review on pharmacotherapy for PAD, specifically focusing on how different drug classes target pro-inflammatory pathways. The goal is to enhance the choice of therapeutic plans by considering their impact on the chronic subclinical inflammation that is associated with PAD development and progression. We conducted a comprehensive review of currently published original articles, narratives, systematic reviews, and meta-analyses. The aim was to explore the relationship between PAD and inflammation and evaluate the influence of current pharmacological and nonpharmacological interventions on the underlying chronic subclinical inflammation. Our findings indicate that the existing treatments have added anti-inflammatory properties that can potentially delay or prevent PAD progression and improve outcomes, independent of their effects on traditional risk factors. Although inflammation-targeted therapy in PAD shows promising potential, its benefits have not been definitively proven yet. However, it is crucial not to overlook the pleiotropic properties of the currently available treatments, as they may provide valuable insights for therapeutic strategies. Further studies focusing on the anti-inflammatory and immunomodulatory effects of these treatments could enhance our understanding of the mechanisms contributing to the residual risk in PAD and pave the way for the development of novel therapies.

Markers of Restenosis after Percutaneous Transluminal Balloon Angioplasty in Patients with Critical Limb Ischemia

Among cardiovascular diseases, chronic obliterating lesions of the arteries of lower extremities, which are one of the important problems of modern healthcare, are distinguished. In most cases, the cause of damage to the arteries of lower extremities is atherosclerosis. The most severe form is chronic ischemia, characterized by pain at rest and ischemic ulcers, ultimately increasing the risk of limb loss and cardiovascular mortality. Therefore, patients with critical limb ischemia need limb revascularization. Percutaneous transluminal balloon angioplasty is one of the least invasive and safe approaches, with advantages for patients with comorbidities. However, after this procedure, restenosis is still possible. Early detection of changes in the composition of some molecules as markers of restenosis will help screen patients at the risk of restenosis, as well as find ways to apply efforts for further directions of inhibition of this process. The purpose of this review is to provide the most important and up-to-date information on the mechanisms of restenosis development, as well as possible predictors of their occurrence. The information collected in this publication may be useful in predicting outcomes after surgical treatment and will also find new ways for the target implication to the mechanisms of development of restenosis and atherosclerosis.

Osteoprotegerin/Receptor Activator of Nuclear Factor-Kappa B Ligand/Receptor Activator of Nuclear Factor-Kappa B Axis in Obesity, Type 2 Diabetes Mellitus, and Nonalcoholic Fatty Liver Disease

PURPOSE OF REVIEW

To summarize evidence on the potential involvement of the osteoprotegerin (OPG)/receptor activator of nuclear factor-kappa B (NF-κΒ) ligand (RANKL)/receptor activator of NF-κΒ (RANK) axis in the pathogenesis of metabolic diseases.

RECENT FINDINGS

The OPG-RANKL-RANK axis, which has been originally involved in bone remodeling and osteoporosis, is now recognized as a potential contributor in the pathogenesis of obesity and its associated comorbidities, i.e., type 2 diabetes mellitus and nonalcoholic fatty liver disease. Besides bone, OPG and RANKL are also produced in adipose tissue and may be involved in the inflammatory process associated with obesity. Metabolically healthy obesity has been associated with lower circulating OPG concentrations, possibly representing a counteracting mechanism, while elevated serum OPG levels may reflect an increased risk of metabolic dysfunction or cardiovascular disease. OPG and RANKL have been also proposed as potential regulators of glucose metabolism and are potentially involved in the pathogenesis of type 2 diabetes mellitus. In clinical terms, type 2 diabetes mellitus has been consistently associated with increased serum OPG concentrations. With regard to nonalcoholic fatty liver disease, experimental data suggest a potential contribution of OPG and RANKL in hepatic steatosis, inflammation, and fibrosis; however, most clinical studies showed reduction in serum concentrations of OPG and RANKL. The emerging contribution of the OPG-RANKL-RANK axis to the pathogenesis of obesity and its associated comorbidities warrants further investigation by mechanistic studies and may have potential diagnostic and therapeutic implications.

Association of serum levels of osteopontin and osteoprotegerin with adverse outcomes after endovascular revascularisation in peripheral artery disease

Background

Osteoprotegerin (OPG) and osteopontin (OPN) are vascular calcification inhibitors with a known role in the atherosclerotic and inflammatory process. We investigated their relationship with adverse outcomes (restenosis/adverse cardiovascular events) after endovascular revascularisation of patients with peripheral arterial disease (PAD).

Methods

203 consecutive patients were enrolled in the PAD group (PADG) and 78 age and sex-matched subjects with less than two cardiovascular risk factors served as control group (COG). PADG underwent standard medical assessment at baseline and 12 months after the procedure. During follow up major adverse cardiovascular events (MACEs) including arterial restenosis with need for reintervention were documented and the PADG was divided accordingly into two subgroups.

Results

During 12-month follow-up, 82 MACE were recorded (MACE subgroup). The rest of 124 PAD patients remained free of MACE (non-MACE subgroup). At baseline, OPG (9.89 ± 2.85 ng/ml vs 3.47 ± 1.95 ng/ml, p < 0.001) and OPN (79.99 ± 38.29 ng/ml vs 35.21 ± 14.84 ng/ml, p < 0.001) levels were significantly higher in PADG compared to COG, as well as in MACE subgroup compared to non-MACE subgroup (13.29 ± 3.23 ng/ml vs 10.86 ± 3 ng/ml and 96.45 ± 40.12 ng/ml vs 78.1 ± 38.29 ng/ml, respectively). An independent association of PAD with OPG and OPN was found in the whole patient cohort. Although OPG and OPN were significantly related to MACE incidence in the univariate analysis, multiple logistic regression analysis failed to detect any independent predictor of MACE within the PADG.

Conclusion

Baseline high OPG and OPN levels were independently associated with PAD presence. Even higher levels of those biomarkers were detected among PAD patients with MACE, however, their prognostic role should be further clarified.

Frailty in Aging and the Search for the Optimal Biomarker: A Review

In the context of accelerated aging of the population worldwide, frailty has emerged as one of the main risk factors that can lead to loss of self-sufficiency in older people. This syndrome is defined as a reduced state of physiological reserve and functional capacity. The main diagnostic tools for frailty are based on scales that show deficits compared to their clinical application, such as the Fried frailty phenotype, among others. In this context, it is important to have one or more biomarkers with clinical applicability that can objectively and precisely determine the degree or risk of frailty in older people. The objective of this review was to analyze the biomarkers associated with frailty, classified according to the pathophysiological components of this syndrome (inflammation, coagulation, antioxidants, and liver function, among others). The evidence demonstrates that biomarkers associated with inflammation, oxidative stress, skeletal/cardiac muscle function, and platelet function represent the most promising markers of frailty due to their pathophysiological association with this syndrome. To a lesser extent but with the possibility of greater innovation, biomarkers associated with growth factors, vitamins, amino acids, and miRNAs represent alternatives as markers of this geriatric syndrome. Likewise, the incorporation of artificial intelligence represents an interesting approach to strengthening the diagnosis of frailty by biomarkers.

Predicting the Risk of Diabetic Foot Ulcers From Diabetics With Dysmetabolism: A Retrospective Clinical Trial

BACKGROUND

Diabetic foot ulcer (DFU) in patients with type 2 diabetes mellitus (T2D) often leads to amputation. Early intervention to prevent DFU is urgently necessary. So far, there have been no studies on predictive models associated with DFU risk factors. Our study aimed to quantify the predictive risk value of DFU, promote health education, and further develop behavioral interventions to reduce the incidence of DFU.

METHODS

Data from 973 consecutive patients with T2D was collected from two hospitals. Patients from the Guangxi Medical University First Affiliated Hospital formed the training cohort (n = 853), and those from the Wuming Hospital of Guangxi Medical University formed the validation cohort (n = 120). Independent variable grouping analysis and multivariate logistic regression analysis were used to determine the risk factors of DFUs. The prediction model was established according to the related risk factors. In addition, the accuracy of the model was evaluated by specificity, sensitivity, predictive value, and predictive likelihood ratio.

RESULTS

In total, 369 of the 853 patients (43.3%) and 60 of the 120 (50.0%) were diagnosed with DFUs in the two hospitals. The factors associated with DFU were old age, male gender, lower body mass index (BMI), longer duration of diabetes, history of foot disease, cardiac insufficiency, no use of oral hypoglycemic agent (OHA), high white blood cell count, high platelet count, low hemoglobin level, low lymphocyte absolute value, and high postprandial blood glucose. After incorporating these 12 factors, the nomogram drawn achieved good concordance indexes of 0.89 [95% confidence interval (CI): 0.87 to 0.91] in the training cohort and 0.84 (95% CI: 0.77 to 0.91) in the validation cohort in predicting DFUs and had well-fitted calibration curves. Patients who had a nomogram score of ≥180 were considered to have a low risk of DFU, whereas those having ≥180 were at high risk.

CONCLUSIONS

A nomogram was constructed by combining 12 identified risk factors of DFU. These 12 risk factors are easily available in hospitalized patients, so the prediction of DFU in hospitalized patients with T2D has potential clinical significance. The model provides a reliable prediction of the risk of DFU in patients with T2D.

Impaired bone matrix glycoprotein pattern is associated with increased cardio-metabolic risk profile in patients with type 2 diabetes mellitus

PURPOSE

Osteopontin (OPN), osteoprotegerin (OPG) and osteocalcin (OC) are matrix glycoproteins which mediate bone mineralization; moreover, their effects on glucose/insulin homeostasis have recently been demonstrated. Higher circulating OPN and OPG levels have been associated with the presence of insulin resistance, atherosclerosis and coronary heart disease. No data are available on contextual changes of these markers in type 2 diabetes mellitus (T2DM). Therefore, aims of this study were to evaluate serum OPN, OPG and OC levels in T2DM patients and their clinical correlates.

METHODS

We recruited 83 consecutive T2DM patients referring to our diabetes outpatient clinics at Sapienza, University of Rome, and 71 non-diabetic sex and age-comparable subjects as a control group. Study population underwent metabolic characterization and carotid ultrasound for intima-media thickness measurement. Plasma OPN, OPG and OC were measured by MILLIPLEX Multiplex Assays Luminex.

RESULTS

T2DM patients had significantly higher circulating OPN and OPG levels than controls (14.3 ± 13.6 vs 10.6 ± 13.7 ng/ml p < 0.001, 0.70 ± 0.60 vs 0.54 ± 4.1 ng/ml, p = 0.02) while OC levels were similar in the two cohorts (6.35 ± 5.8 vs 7.80 ± 7.0 ng/ml, p = n.s). OPN and OPG positively correlated with greater systolic blood pressure (SBP) values, HOMA-IR and HOMA-β, and with the presence of dyslipidemia and carotid atherosclerosis. The association between greater OPN and OPG levels and SBP was independent from possible confounders (both p = 0.01).

CONCLUSIONS

Circulating OPN and OPG levels are increased in T2DM patients and identify a particularly unfavourable metabolic profile, mostly expressed by higher SBP. Bone peptides may represent novel markers of vascular stress and accelerated atherosclerosis in diabetes, constituting a possible tool for cardiovascular risk stratification in diabetes.

The role of OPG/RANKL in the pathogenesis of diabetic cardiovascular disease

Cardiovascular (CV) disease is the leading cause of mortality in patients with type 2 diabetes mellitus. A major factor in the pathogenesis of CV disease is vascular calcification (VC), which is accelerated in type 2 diabetes mellitus. Calcification of the vessel wall contributes to vascular stiffness and left ventricular hypertrophy whereas intimal calcification may predispose to plaque rupture and CV death. The pathogenesis of VC is complex but appears to be regulated by the osteoprotegerin (OPG)/receptor activator of nuclear factor-κB ligand (RANKL) signaling pathway, which is involved in bone remodeling. Within the bone, OPG prevents RANKL from binding to receptor activator of nuclear factor-κB and inhibiting bone resorption. Outside of the bone, the clinical significance of OPG blocking RANKL is not well understood, but OPG knockout mice that lack OPG develop early and severe VC. This minireview outlines some of the research on OPG/RANKL in the pathogenesis of VC and discusses potential therapies, which may reduce VC and CV burden in humans.

Osteoprotegerin concentration is associated with the presence and severity of peripheral arterial disease in type 2 diabetes mellitus

BACKGROUND

Osteoprotegerin plays a role in the development of several bone diseases. In addition, osteoprotegerin may contribute to the development of vascular disease. Little is known about the association between serum osteoprotegerin levels and the presence or severity of peripheral arterial disease (PAD). The aim of this study was to examine the association between serum osteoprotegerin levels and both the presence as well as the severity of lower extremity arterial disease in patients with type 2 diabetes (T2DM).

PATIENTS AND METHODS

The study included 165 consecutive patients with T2DM (57 % males, mean age 65.0 ± 0.7 years). PAD was diagnosed by measurement of the toe-brachial index (TBI). Serum osteoprotegerin was measured using ELISA.

RESULTS

The mean osteoprotegerin level was significantly higher in patients with PAD in comparison to patients without PAD (18.2 ± 1.0 vs. 13.1 ± 2.0 pmol/L, p = 0.014). Significant univariate correlations between TBI and osteoprotegerin level (r = -0.308; p < 0.001), age, body mass index, and HDL cholesterol were observed. In the multivariate linear regression analysis, serum osteoprotegerin (β = -0.005; p = 0.020), higher age, and male gender were significant predictors of TBI. When 25(OH) vitamin D was introduced into the mentioned model, OPG was no longer a significant predictor of TBI and was replaced in the model with vitamin D (β = 0.009, p = 0.001). This finding suggests a role of OPG as a mediator of the effects of 25(OH) vitamin D.

CONCLUSIONS

Serum osteoprotegerin level is significantly associated with both the presence and severity of PAD in patients with T2D. Osteoprotegerin might be a biomarker for the presence of atherosclerotic disease in patients with T2DM.

Peripheral Arterial Disease in Type 2 Diabetes Is Associated with an Increase in Fibrinogen Levels

BACKGROUND

The present study is undertaken to investigate the fibrinogen levels in type 2 diabetes mellitus (T2DM) and its relation to peripheral artery disease (PAD) based on a more accurate and applied noninvasive measurements of duplex ultrasonography.

METHODS

We performed a cross-sectional study including 1096 T2DM patients (474 males and 622 females). The odds ratios (ORs) and 95% confidence intervals (CIs) were presented to show the association between PAD and fibrinogen in the subjects divided by fibrinogen levels quarterly. Furthermore, the univariate and multiple logistic analyses were performed to explore the correlation between PAD and fibrinogen levels, individual components in the cross-sectional study.

RESULTS

Finally, 887 (80.9%) T2DM patients meet the diagnostic criteria of PAD and these patients had considerably higher serum fibrinogen concentration than non-PAD group (P < 0.001). Multiple logistic analyses revealed that higher fibrinogen quartiles were positively related with the development of PAD in the adjusted model. After adjusting for known confounding parameters, the ORs for PAD were 1.993 (95% CI: 1.322-3.005, P < 0.001), 2.469 (95% CI: 1.591-3.831, P < 0.001), and 2.942 (95% CI, 1.838-4.711, P < 0.001) for Q2, Q3, and Q4, respectively (all P values <0.05).

CONCLUSIONS

Our results suggest that serum fibrinogen concentration can be considered as an independent risk factor for PAD in T2DM patients.

Is cardiovascular disease in patients with diabetes associated with serum levels of MMP-2, LOX, and the elastin degradation products ELM and ELM-2?

BACKGROUND

Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered mRNA-expression in diabetic patients, namely matrix metalloproteinase 2 (MMP-2), lysyl oxidase (LOX) and elastin itself. In this study we investigate whether the serum concentrations of elastin-related proteins correlate to signs of CVD in patients with T2DM.

METHODS

Blood samples from 302 type 2 diabetic patients were analysed for MMP-2, LOX, and the elastin degradation products ELM and ELM2. The results were investigated for correlations to signs of CVD in different vascular territories, as determined by myocardial perfusion scintigraphy, carotid artery thickness and ankle-brachial blood pressure index.

RESULTS

T2DM patients with peripheral arterial disease (low ankle-brachial index) (PAD) display higher levels of MMP-2 and ELM compared to patients without PAD. However, none of the proteins or degradation products correlated with myocardial ischemia or a combined measure of CVD-signs, including myocardial ischemia, increased carotid thickness and decreased ankle-brachial blood pressure.

CONCLUSIONS

Our results suggest that the diabetic environment affects the circulating amounts of MMP-2 and ELM in patients with PAD. However, the same connection could not be seen in diabetic patients with CVD broadly identified in three vascular territories. LOX and ELM-2 did not correlate to any type of CVD. Overall, serum levels of elastin-related molecules are only remotely related to CVD in type 2 diabetes.

Serum Tartrate-resistant Acid Phosphatase-5b Levels are Associated with the Severity and Extent of Coronary Atherosclerosis in Patients with Coronary Artery Disease

Aims: Tartrate-resistant acid phosphatase (TRACP)-5b and osteoprotegerin (OPG) are specific and sensitive markers of bone resorption in patients with rheumatoid arthritis (RA) and chronic kidney disease (CKD). The TRACP-5b level is associated with the severity of RA and CKD, while the OPG level is associated with the severity of coronary atherosclerosis and calcification, and can predict a poor outcome in patients with coronary artery disease (CAD). However, the impact of TRACP-5b on coronary atherosclerosis in CAD patients remains unclear.

Methods: A total of 71 CAD patients (57 men, 14 women; mean age: 69.0 ± 9.7 years) and 28 age- and gender-matched healthy subjects were investigated. The number of diseased vessels (a marker of the severity of coronary atherosclerosis) and the Gensini score (a marker of the extent of coronary atherosclerosis), as well as the OPG and TRACP-5b levels were measured in CAD patients. The TRACP-5b levels were classified into quartiles.

Results: The TRACP-5b levels were significantly higher in CAD patients than in healthy subjects. Patients with higher TRACP-5b levels had higher OPG levels and Gensini scores than those with lower TRACP-5b levels. Higher TRACP-5b levels were associated with an increased number of diseased vessels. A multivariate linear regression analysis showed that the OPG level and the number of diseased vessels or the Gensini score were significantly and independently associated with the TRACP-5b level.

Conclusions: These data indicate that the TRACP-5b level is significantly associated with the OPG level and with the severity and extent of coronary atherosclerosis in CAD patients.

New semiquantitative ultrasonographic score for peripheral arterial disease assessment and its association with cardiovascular risk factors

The data concerning the distribution, extent and progression of peripheral arterial disease (PAD), as well as its association with traditional cardiovascular (CV) risk factors, have generally been obtained from studies of patients in advanced stages of the disease undergoing surgical or endovascular treatment. In this study, we have introduced a new semiquantitative ultrasonographic score (ultrasonographic lower limb atherosclerosis (ULLA) score) that is able to categorize lower limb atherosclerotic lesions at all stages of PAD. We then associated these ultrasonographic categories with a CV risk profile. We enrolled 320 consecutive subjects with symptoms suggestive of PAD or with known CV risk factors referring to our angiology unit between 1 July 2014 and 30 June 2015 for ultrasonographic evaluation of the lower limb arteries. Femoropopliteal and run-off segments were categorized together and separately based on their ultrasonographic characteristics. In univariate and multivariate analyses, the ULLA scores were significantly associated with the main CV risk factors, that is, age, male gender, cigarette smoking, arterial hypertension, diabetes, dyslipidemia, sedentary lifestyle, previous CV events and family history of CV disease, and also confirming the specific association of single risk factors with different segments of lower limb arteries. The proposed ULLA score enables a complete evaluation of the entire lower limb atherosclerotic burden, extending the results concerning the association of PAD with CV risk factors to all stages of the disease, including the early stages. It can be feasible that this new score will facilitate better evaluation of the progression of PAD and its prospective role in CV risk stratification.

The signature of circulating microparticles in heart failure patients with metabolic syndrome

The role of pattern of circulating endothelial cell-derived microparticles, platelet-derived microparticles (PMPs), and monocyte-derived microparticles (MMPs) in metabolic syndrome (MetS) patients with chronic heart failure (CHF) is not still understood. The aim of the study was to investigate a pattern of circulating microparticles (MPs) in MetS patients with CHF in relation to neurohumoral and inflammatory activation. The study retrospectively involved 101 patients with MetS and 35 healthy volunteers. Biomarkers were measured at baseline of the study. The results of the study have shown that numerous circulating PMPs- and MMPs in subjects with MetS (with or without CHF) insufficiently distinguished from level obtained in healthy volunteers. We found elevated level of CD31+/annexin V+ MPs in association with lower level of CD62E+ MPs. Therefore, we found that biomarkers of biomechanical stress serum N-terminal brain natriuretic peptide and inflammation (high-sensitive C-reactive protein ,osteoprotegerin) remain statistically significant predictors for decreased CD62E+ to CD31+/annexin V+ ratio in MetS patients with CHF. In conclusion, decreased CD62E+ to CD31+/annexin V+ ratio reflected that impaired immune phenotype of MPs may be discussed as a surrogate marker of CHF development in MetS population.

High osteoprotegerin is associated with development of foot ulcer in type 1 diabetes

BACKGROUND AND AIM

The bone-related peptide osteoprotegerin has been linked to vascular calcification and peripheral vascular disease. We investigated the association between osteoprotegerin and development of foot complications in persons with type 1 diabetes.

MATERIALS AND METHODS

Prospective observational study of 573 persons with type 1 diabetes, 225 women; age [mean±SD] 42.3±10.3years. Plasma osteoprotegerin was measured by ELISA.

RESULTS

Median (IQR) osteoprotegerin was 2.80(2.35-3.63)μg/L and follow-up time (median (range)) was 12.7(0.1-15.6)years. Endpoints included: new foot ulceration (n=153), Charcot foot (n=14), vascular surgery/amputation (n=53), loss of foot pulse (n=57), and peripheral neuropathy (n=99). In unadjusted analyses, higher osteoprotegerin was associated with development of all endpoints (p≤0.026). Higher osteoprotegerin remained associated with development of foot ulcer, and the combination of vascular surgery/amputation, loss of foot pulse and neuropathy (p≤0.001) in a sex and age adjusted model. After further adjustment (nephropathy status, smoking, HbA_1c, systolic blood pressure, serum cholesterol, high sensitivity C-reactive protein, eGFR, and presence of neuropathy and/or claudication and/or foot ulcer at baseline), higher osteoprotegerin remained associated with development of foot ulcer (HR (95% CI) per doubling: 1.75 (1.04-2.97); p=0.037).

CONCLUSION

Higher osteoprotegerin levels were associated with development of foot ulcer, even after comprehensive adjustment.

High circulating osteoprotegerin levels are associated with non-zero blood groups

BACKGROUND

Osteoprotegerin (OPG) and von Willebrand factor (VWF) form complex within endothelial cells and following secretion. The nature of blood group antigens strongly influences the levels of circulating VWF, but there is no available data concerning its ascendancy on OPG levels. We aimed to assess the relationship of AB0 blood groups with OPG, VWF levels (VWF: Ag) and collagen binding activity (VWF: CB) in peripheral arterial disease (PAD) patients.

METHODS

Functional and laboratory parameters of 105 PAD patients and 109 controls were examined. Results of OPG, VWF: Ag, VWF: CB (ELISA-s) were analysed by comparative statistics, together with clinical data.

RESULTS

OPG levels were higher in patients than in controls (4.64 ng/mL vs. 3.68 ng/mL, p < 0.001). Among patients elevation was marked in the presence of critical limb ischemia (5.19 ng/mL vs. 4.20 ng/mL, p = 0.011). The OPG in patients correlated positively with VWF: Ag and VWF: CB (r = 0.26, p = 0.008; r = 0.33, p = 0.001) and negatively with ankle-brachial pressure index (r = -0.22, p = 0.023). Furthermore, OPG was significantly elevated in non-0 blood groups compared to 0-groups both in patients and controls (4.95 ng/mL vs. 3.90 ng/mL, p = 0.012 and 4.09 ng/mL vs. 3.40 ng/mL, p = 0.002).

CONCLUSIONS

OPG levels are associated to blood group phenotypes and higher in non-0 individuals. Increased OPG levels in PAD characterize disease severity. The significant correlation between OPG and VWF:CB might have functional importance in an atherothrombosis-prone biological environment.

Biomarkers of oxidative stress are associated with frailty: the Framingham Offspring Study

Cardiovascular disease and frailty frequently occur together. Both are associated with inflammation, which may be partially triggered by oxidative stress, especially in cardiovascular disease. We investigated whether inflammatory and oxidative stress biomarkers linked to cardiovascular disease were associated with frailty and the related outcome of gait speed. We report cross-sectional associations of biomarkers and frailty assessed at Framingham Offspring Study cycle eight. Participants ≥60 years were eligible if they had information on frailty and at least one of the following: C-reactive protein, interleukin-6, tumor necrosis factor receptor 2, 8-epi-FGFα isoprostanes (isoprostanes), lipoprotein phospholipase A2 (LpPLA2) mass or activity, osteoprotegerin, intracellular adhesion molecule-1, monocyte chemoattractant protein-1 or P-selectin. Stepwise logistic models were utilized for frailty and stepwise linear models for gait speed. Covariates included age, sex, body mass index, smoking, and co-morbidities. Odds ratios (ORs) and slope estimates (B) are reported per standard deviation increase of loge-transformed biomarker. Of the 1919 participants, 142 (7 %) were frail. In a stepwise model, frailty odds increased with higher interleukin-6 (OR 1.90, 95 % CI 1.51, 2.38), isoprostanes (OR 1.46, 95 % CI 1.12, 1.92), and LpPLA2 mass (OR 1.29, 95 % CI 1.00, 1.65). Stepwise regression found that slower gait speeds were associated with interleukin-6 (B = -0.025 m/s, 95 % CI 0.04, -0.01), isoprostanes (B = -0.019, 95 % CI -0.03, -0.008), LpPLA2 mass (B = -0.016, 95 % CI -0.03, -0.004), and osteoprotegerin (B = -0.015, 95 % CI -0.03, -0.002, all p < 0.05). Interleukin-6, isoprostanes, and LpPLA2 mass were associated with greater frailty odds and slower gait speeds. Oxidative stress may be a mechanism contributing to frailty.

Association of plasma osteoprotegerin levels with the severity of lower extremity arterial disease in patients with type 2 diabetes

Background

Osteoprotegerin (OPG) is a member of the tumor necrosis factor receptor superfamily and suggested as a marker of atherosclerosis. However, little is known about the association between plasma OPG levels and lower extremity arterial disease. We investigated whether plasma OPG levels were associated with the presence and severity of lower extremity arterial disease in patients with type 2 diabetes.

Methods

This was a study of 712 patients with type 2 diabetes aged 40 years or older. Plasma OPG was measured using ELISA. The lower extremity arterial disease was diagnosed by high-frequency color Doppler ultrasonic.

Results

Of 712 patients, 505 (70.9 %) had lower extremity arterial stenosis. OPG levels were significantly increased in patients with lower extremity arterial stenosis [1.89 (1.48-2.41) vs. 2.39 (1.82-3.33) ng/mL, p < 0.001]. Plasma OPG levels increased gradually with increasing severity of lower extremity arterial stenosis (p < 0.001 for trend), after adjustment for traditional cardiovascular risk factors such as age, gender, smoking, total cholesterol, high-density lipoprotein (HDL) cholesterol, C-reactive protein (CRP), body mass index (BMI), systolic blood pressure(SBP). The risk of lower extremity arterial disease was increased (OR = 1.17, 95 % CI 1.09 –1.28, p < 0.001) with each standard deviation (SD) higher level of OPG in patients with type 2 diabetes after adjustment for traditional CVD risk factors.

Conclusions

Plasma OPG levels were significantly associated with the presence and severity of lower extremity arterial disease. Our results suggest that OPG is an important plasma biomarker of lower extremity arterial disease in type 2 diabetes.

Impaired immune phenotype of circulating endothelial-derived microparticles in patients with metabolic syndrome and diabetes mellitus

INTRODUCTION

Type two diabetes mellitus (T2DM) remains a leading contributor to cardiovascular mortality worldwide. This study was conducted to investigate the pattern of circulating EMPs in T2DM patients in comparison with MetS subjects.

METHODS

The study retrospectively included 101 patients (54 subjects with T2DM and 47 patients with MetS) and 35 healthy volunteers. All the patients gave written informed consent for participation in the study. Biomarkers were measured at baseline of the study.

RESULTS

There is a significant difference between healthy subjects and patients regarding CD31+/annexin V+ EMPs to CD62E+ EMPs ratio, which reflects impaired phenotype of EMPs. Therefore, CD31+/annexin V+ EMPs to CD62E+ EMPs ratio was found to be higher in the T2DM patients compared to MetS patients. Using multivariate linear regression analyses, independent impact of T2DM (r = 0.40, P = 0.003), OPG (r = 0.37, P = 0.001), hs-CRP (r = 0.347, P = 0.001), and adiponectin (r = 0.33, P = 0.001) on increased CD31+/annexin V+ to CD62E+ ratio of EMPs was determined. Using C-statistics, we found that inflammatory biomarkers (hs-C-reactive protein, osteoprotegerin and adiponectin) added to the base model (T2DM) improved the relative IDI by 12.6 % for increased CD31+/annexin V+ EMPs to CD62E+ EMPs ratio.

CONCLUSION

We found that patients with T2DM and MetS may be distinguished by predominantly appearing phenotypes of circulating EMPs associated with pro-inflammatory cytokine overproduction. Elevated CD31+/annexin V+ EMPs to CD62E+ EMPs ratio is an indicator of impaired immune phenotype of EMPs, which allows determining the pattern of EMPs in dysmetabolic disorder patients.

Osteoprotegerin concentrations in patients with suspected reversible myocardial ischemia: observations from the Akershus Cardiac Examination (ACE) 1 Study

Increased circulating osteoprotegerin (OPG) levels have been associated with the prevalence and severity of coronary artery disease and the risk of cardiovascular death. OPG is a cytokine of the tumor necrosis factor receptor superfamily and is expressed in various cell types in the body, including osteoblasts, inflammatory cells, vascular smooth muscle cells/endothelial cells and cardiomyocytes. The main sources determining OPG levels in the circulation however, are not well understood, and whether reversible myocardial ischemia influences OPG levels are not known. Accordingly, OPG levels were measured in 198 patients referred for exercise stress testing and myocardial perfusion imaging (MPI). In addition OPG levels were measured in 8 healthy control subjects performing a maximal bicycle stress test. Plasma samples were collected before, immediately after, 1.5h and 4.5h after exercise stress testing with MPI. OPG levels at baseline were not different in patient with reversible myocardial ischemia (n=19) and patients without reversible ischemia (n=179) (4.7 [3.6-5.5]pmol/L vs. 4.3 [3.4-5.2]pmol/L, p=0.21), and there was an increase in OPG levels immediately after exercise regardless of whether or not the patient had reversible ischemia on MPI (absolute increase: 0.2 [0-0.55]pmol/L vs. 0.3 [0-0.5]pmol/L, p=0.72). OPG levels also increased immediately after stress in the 8 control subjects (3.5 (3.2-3.8)pmol/L at baseline to 3.8 (3.5-4.7), p=0.008). In conclusion, OPG levels increase acutely during exercise stress testing, but this increase is likely caused by mechanisms other than myocardial ischemia.

Osteoprotegerin in Cardiometabolic Disorders

Osteoprotegerin (OPG), a glycoprotein traditionally implicated in bone remodelling, has been recently related to cardiovascular disease (CVD). Human studies show a positive relationship between circulating OPG, vascular damage, and CVD, and as such OPG has emerged as a potential biomarker for CVD. This review focuses on the relationship between circulating OPG and different endocrine cardiometabolic alterations such as type 1 and 2 diabetes. The association of OPG with diabetic complications (neuropathy, nephropathy, or retinopathy) as well as with atherosclerosis, coronary artery calcification, morbidity, and mortality is pointed out. Moreover, OPG modulation by different treatments is also established. Besides, other associated diseases such as obesity, hypertension, and metabolic syndrome, which are known cardiovascular risk factors, are also considered.

Plasma calprotectin and its association with cardiovascular disease manifestations, obesity and the metabolic syndrome in type 2 diabetes mellitus patients

Background

Plasma calprotectin is a potential biomarker of cardiovascular disease (CVD), insulin resistance (IR), and obesity. We examined the relationship between plasma calprotectin concentrations, CVD manifestations and the metabolic syndrome (MetS) in patients with type 2 diabetes mellitus (T2DM) in order to evaluate plasma calprotectin as a risk assessor of CVD in diabetic patients without known CVD.

Methods

An automated immunoassay for determination of plasma calprotectin was developed based on a fecal Calprotectin ELIA, and a reference range was established from 120 healthy adults. Plasma calprotectin concentrations were measured in 305 T2DM patients without known CVD. They were screened for carotid arterial disease, peripheral arterial disease (PAD), and myocardial ischemia (MI) by means of carotid artery ultrasonography, peripheral ankle and toe systolic blood pressure measurements, and myocardial perfusion scintigraphy.

Results

The reference population had a median plasma calprotectin concentration of 2437 ng/mL (2.5-97.5% reference range: 1040–4262 ng/mL). The T2DM patients had significantly higher concentrations (3754 ng/mL, p < 0.0001), and within this group plasma calprotectin was significantly higher in patients with MetS (p < 0.0001) and also in patients with autonomic neuropathy, PAD, and MI compared with patients without (p < 0.001, p = 0.021 and p = 0.043, respectively). Plasma calprotectin was by linear regression analysis found independently associated with BMI, C-reactive protein, and HDL cholesterol. However, plasma calprotectin did not predict autonomic neuropathy, PAD, MI or CVD when these variables entered the multivariable regression analysis as separate outcome variables.

Conclusion

T2DM patients had higher concentrations of plasma calprotectin, which were associated with obesity, MetS status, autonomic neuropathy, PAD, and MI. However, plasma calprotectin was not an independent predictor of CVD, MI, autonomic neuropathy or PAD.

Trial registration number

NCT00298844

Association of serum and vitreous concentrations of osteoprotegerin with diabetic retinopathy

BACKGROUND

Angiogenesis is involved in the pathogenesis of diabetic retinopathy. Osteoprotegerin, a recently identified glycoprotein belonging to the tumour necrosis factor receptor superfamily, has been implicated to be correlated with angiogenesis. This study aims to determine whether serum and vitreous concentrations of osteoprotegerin are associated with diabetic retinopathy.

METHODS

This study consisted of 254 diabetic patients (100 without diabetic retinopathy, 64 with non-proliferative diabetic retinopathy and 90 with proliferative diabetic retinopathy) and 62 control subjects. Serum and vitreous concentrations of osteoprotegerin were evaluated using enzyme-linked immunosorbent assay method.

RESULTS

Serum and vitreous osteoprotegerin concentrations in proliferative diabetic retinopathy patients were significantly elevated compared with those of the other three groups. Non-proliferative diabetic retinopathy patients showed elevated concentrations of serum and vitreous osteoprotegerin compared with patients without diabetic retinopathy. In addition, control subjects had significantly lower serum and vitreous osteoprotegerin concentrations compared with diabetic patients without retinopathy, non-proliferative diabetic retinopathy patients and proliferative diabetic retinopathy patients.

CONCLUSIONS

Serum and vitreous osteoprotegerin concentrations are associated with the presence and severity of diabetic retinopathy.

Relation of osteoprotegerin in severe aortic valve stenosis to postoperative outcome and left ventricular function

Osteoprotegerin (OPG) is a member of the tumor necrosis factor receptor superfamily and is known to be among the mediators of the calcification process that has been shown to increase in patients with aortic stenosis (AS). The aim of this study was to characterize the association of OPG with left ventricular (LV) function and remodeling and to evaluate the significance of preoperative OPG on long-term outcome in terms of survival and symptomatic improvement in 124 patients with severe AS scheduled for aortic valve replacement (AVR). Patients were divided according to tertiles of preoperative OPG. Preoperative OPG was associated with age, EuroSCORE, and preoperative functional capacity. Despite similar ejection fraction and diastolic function among groups, longitudinal LV systolic function consistently decreased and markers of filling pressure increased across groups. During median follow-up of 4 years, 41 patients died of a presumed cardiovascular cause or remained in New York Heart Association functional class III or IV. The risk of a poor postoperative outcome after AVR increased with increasing OPG tertiles (15% vs 33% vs 51%, p = 0.002). In a multivariate model containing age, ejection fraction, N-terminal pro-brain natriuretic peptide and left atrial volume index, OPG was still significantly associated with postoperative outcome. In addition, OPG levels associated with cardiovascular mortality during follow-up. In conclusion, OPG is associated with LV and left atrial remodeling in patients with symptomatic severe AS undergoing AVR. Moreover, plasma OPG is associated with long-term postoperative outcome and may identify patients with poor symptomatic improvement after surgery.

Influence of fibrinogen and C-RP on progression of peripheral arterial disease in type 2 diabetes: a preliminary report

Background

Limited studies have suggested that inflammatory biomarkers play a role in the initiation and progression of atherosclerosis in diabetic patients. This study assesses the effect of inflammatory biomarkers: fibrinogen and C-reactive protein (C-RP) on the progression of peripheral arterial disease (PAD) in type 2 diabetic (T2D) patients.

Methods

Sixty two patients with T2D and PAD (mean age 60.28 ± 27 years and diabetes duration of 8.58 ± 6.17 years) were enrolled in a cohort prospective study of 36 months. Ankle-brachial index (ABI) was measured in all patients at baseline and after 36 months. Multiple linear regression analysis was used to determine the predictivity of variables for fibrinogen, C-RP, plasma lipid fractions, fasting plasma glucose, Body Mass Index (BMI), duration of diabetes status and the age on changes in ABI value.

Results

Linear regression analysis defined F as a predictor for endpoint value of ABI (β = 0.469, p = 0.007). Value of C-RP determinates change of minimal value of ABI (β = 0.449, p = 0.037) and change of mean ABI per year (β = 0.442, p = 0.025).

Conclusion

Our data indicate that plasma determination of fibrinogen and C-RP might have a clinical implication in defining the process of progression of PAD in T2D population.

Association of serum osteoprotegerin with vascular calcification in patients with type 2 diabetes

Background

Osteoprotegerin is a member of the tumor necrosis factor-related family and inhibits RANK stimulation of osteoclast formation as a soluble decoy receptor. The goal of this study was to determine the relationship of serum osteoprotegerin with vascular calcification in patients with type 2 diabetes.

Methods

The subjects were 124 patients with type 2 diabetes mellitus, including 88 males and 36 females with a mean (± SD) age of 65.6 ± 8.2 years old. Serum levels of osteoprotegerin, osteocalcin, fibroblast growth factor 23 (FGF23), 25-hydroxyvitamin D3 and adiponectin were measured by ELISA. Vascular calcification in the cervical artery was examined by ultrasound sonography. The subjects were divided into 4 quartiles depending on serum osteoprotegerin levels.

Results

Vascular calcification was significantly higher in the 4th quartile and significantly lower in the 1st quartile of serum osteoprotegerin levels, compared to other quartiles. There were no differences in serum osteoprotegerin and vascular calcification among patients with different stages of diabetic nephropathy, but serum FGF23 levels were elevated in those with stage 4 diabetic nephropathy. Simple regression analysis showed that serum osteoprotegerin levels had significant positive correlations with age, systolic blood pressure and serum adiponectin levels, and significant negative correlations with BMI and serum 25-hydroxyvitamin D3.

Conclusions

These findings suggest that elevated serum osteoprotegerin may be involved in vascular calcification independently of progression of diabetic nephropathy in patients with type 2 diabetes.

Plasma concentrations of extracellular matrix protein fibulin-1 are related to cardiovascular risk markers in chronic kidney disease and diabetes

BACKGROUND

Fibulin-1 is one of a few extracellular matrix proteins present in blood in high concentrations. We aimed to define the relationship between plasma fibulin-1 levels and risk markers of cardiovascular disease.

METHODS

Plasma fibulin-1 was determined in subjects with chronic kidney disease (n = 32; median age 62.5, inter-quartile range 51 - 73 years) and 60 age-matched control subjects. Among kidney disease patients serological biomarkers related to cardiovascular disease (fibrinogen, interleukin 6, C-reactive protein) were measured. Arterial applanation tonometry was used to determine central hemodynamic and arterial stiffness indices.

RESULTS

We observed a positive correlation of fibulin-1 levels with age (r = 0.38; p = 0.033), glycated hemoglobin (r = 0.80; p = 0.003), creatinine (r = 0.35; p = 0.045), and fibrinogen (r = 0.39; p = 0.027). Glomerular filtration rate and fibulin-1 were inversely correlated (r = -0.57; p = 0.022). There was a positive correlation between fibulin-1 and central pulse pressure (r = 0.44; p = 0.011) and central augmentation pressure (r = 0.55; p = 0.001). In a multivariable regression model, diabetes, creatinine, fibrinogen and central augmentation pressure were independent predictors of plasma fibulin-1.

CONCLUSION

Increased plasma fibulin-1 levels were associated with diabetes and impaired kidney function. Furthermore, fibulin-1 levels were associated with hemodynamic cardiovascular risk markers. Fibulin-1 is a candidate in the pathogenesis of cardiovascular disease observed in chronic kidney disease and diabetes.

Osteoprotegerin as a marker of atherosclerosis in diabetic patients

Atherosclerosis is the principal cause of cardiovascular disease (CVD) and has many risk factors, among which is diabetes. Osteoprotegerin (OPG) is a soluble glycoprotein, involved in bone metabolism. OPG is also found in other tissues, and studies have shown that it is expressed in vascular smooth muscle cells. OPG has been implicated in various inflammations and also has been linked to diabetes mellitus. Increased serum OPG levels were found in patients with diabetes and poor glycemic control. Furthermore, prepubertal children with type 1 diabetes have significantly increased OPG levels. Receptor activator of nuclear factor kappa-B ligand (RANKL) is not found in the vasculature in normal conditions, but may appear in calcifying areas. OPG and RANKL are important regulators of mineral metabolism in both bone and vascular tissues. Few data are available on the relationship between plasma OPG/RANKL levels and endothelial dysfunction as assessed using noninvasive methods like ultrasound indexes, neither in the general population nor, more specifically, in diabetic patients. The aim of our review study was to investigate, based on the existing data, these interrelationships in order to identify a means of predicting, via noninvasive methods, later development of endothelial dysfunction and vascular complications in diabetic patients.

Efficacy of endoluminal interventional therapy in diabetic peripheral arterial occlusive disease: a retrospective trial

Background

The purpose of this study was to assess the efficacy of interventional therapy for peripheral arterial occlusive disease and the difference between diabetic patients and non-diabetic patients.

Methods

139 consecutive patients between September 2006 and September 2010 who underwent percutaneous lower extremity revascularization for arterial lesions were divided into diabetes group (n = 62) and non-diabetes group (n = 77). Before intervention, rest ankle brachial indexes and three dimensional computed tomography angiography from abdominal aorta to tiptoe were performed. The interventional treatments included angioplasty with or without stenting. The clinical outcomes included rest ankle-brachial indexes, primary patency rates, secondary patency rates and limb-salvage rates for 6-month, 12-month, 24-month and 36-month after treatment. The primary and secondary patency rates of all interventions and the limb-salvage rates of the patients are illustrated by Kaplan-Meier curves and compared by log-rank analysis.

Results

The interventional operation success rates were 98.4% (61/62) in diabetes group and 100% (77/77) in non-diabetes group. The re-interventional operation success rates were 85.7% (18/21) in diabetes group and 76.9% (20/26) in non-diabetes group. The mean value of ankle brachial indexes was significantly increased after intervention (0.397 ± 0.125 versus 0.779 ± 0.137, t = -25.780, P < 0.001) in diabetes group and (0.406 ± 0.101 versus 0.786 ± 0.121, t = -37.221, P < 0.001) in non-diabetes group. Perioperative 30-day mortality was 0%. Major complications included groin hematoma in 7.2%, and pseudoaneurysm formation 2.2%. In diabetes group, 6, 12, 24, and 36-month primary patency rates were 88.7% ± 4.0%, 62.3% ± 6.6%, 55.3% ± 7.0%, and 46.5% ± 7.5%; secondary patency rates were 93.5% ± 3.1%, 82.3% ± 5.1%, 70.8% ± 6.5%, and 65.7% ± 7%; limb-salvage rates were 95.2% ± 2.7%, 87.7% ± 4.4%, 85.5% ± 4.8%, and 81.9% ± 5.8%. In non-diabetes group, 6, 12, 24, and 36-month primary patency rates were 90.9% ± 3.3%, 71.8% ± 5.4%, 71.8% ± 5.4%, and 60.9% ± 6.2%; secondary patency rates were 96.1% ± 2.2%, 91.6% ± 3.3%, 82.7% ± 4.8%, and 71.8% ± 6.2%; limb-salvage rates were 97.4% ± 1.8%, 94.4% ± 2.7%, 90.6% ± 3.7%, and 83.1% ± 5.4%. The differences between two groups were not significant (P > 0.05).

Conclusion

With a low risk of morbidity and mortality, the percutaneous revascularization accepted by patients does not affect ultimate necessary surgical revascularization and consequently should be considered as the preferred therapy for chronic lower extremity ischemia. The efficacy and prognosis of interventional therapy in diabetic patients is similar that in non-diabetic patients.