Osteoprotegerin as a predictor of coronary artery disease and cardiovascular mortality and morbidity

Association of Serum Osteoprotegerin With Vascular Calcification, and Cardiovascular and Graft Outcomes in Kidney Transplant Patients: Results From the KNOW-KT

BACKGROUND

Vascular calcification and stiffness contribute to increased cardiovascular morbidity in patients with chronic kidney disease. This study investigated associations between serum osteoprotegerin (OPG) levels and vascular calcification or stiffness to assess cardiovascular and graft outcomes in kidney transplant patients.

METHODS

The KoreaN cohort study for Outcome in patients With Kidney Transplantation was a prospective multicenter cohort study. Serum OPG levels were measured at baseline and 3 y after transplantation in 1018 patients. Patients were classified into high and low OPG groups according to median serum OPG levels. The median follow-up duration was 93.5 mo.

RESULTS

The mean age was 45.8 ± 11.7 y and 62.9% were men. Patients with high OPG had significantly higher coronary artery calcium scores, abdominal aortic calcification scores, and brachial-ankle pulse wave velocities than those with lower OPG; these parameters remained significant for 5 y after transplantation. The 3-y OPG levels were lower than baseline values ( P  < 0.001) and were positively correlated ( r  = 0.42, P  < 0.001). Multivariate Cox regression analysis showed that high OPG levels were significantly associated with posttransplant cardiovascular events ( P  = 0.008) and death-censored graft loss ( P  = 0.004). Similar findings regarding posttransplant cardiovascular events ( P  = 0.012) and death-censored graft loss ( P  = 0.037) were noted in patients with high OPG at the 3-y follow-up. Mediation analyses revealed that coronary artery calcium scores, abdominal aortic calcification scores, and brachial-ankle pulse wave velocities could act as mediators between serum OPG levels and posttransplant cardiovascular events.

CONCLUSIONS

Serum OPG concentration is associated with vascular calcification and stiffness and could be a significant risk factor for cardiovascular outcomes and graft loss in patients undergoing kidney transplantation.

Assessment of osteoprotegerin and RANKL levels and several cardiovascular risk scoring systems in acromegaly

PURPOSE

The OPG/RANKL (osteoprotegerin/receptor activator of nuclear factor kappa-B) system, which plays a crucial role in bone metabolism, is also associated with vascular calcification. Acromegaly is characterized by excessive secretion of growth hormone and insulin-like growth factor, and studies have demonstrated an elevated risk of cardiovascular disease in individuals with acromegaly. In this study, our objective was to investigate the relationship between OPG/RANKL and various cardiovascular risk scoring systems.

METHODS

We recruited 44 consecutive acromegaly patients and 41 healthy controls with a similar age and gender distribution for this study.

RESULTS

While RANKL levels were significantly higher in the acromegaly group compared to the controls, OPG levels were not found to be significantly different between the two groups. Furthermore, within the acromegaly group, RANKL levels were significantly higher in patients with active acromegaly compared to those with controlled acromegaly. Osteoprotegerin levels showed a positive correlation with the Framingham risk score (FRS) in the acromegaly group. Linear regression analysis revealed an association of OPG with FRS (adjusted R2 value of 21.7%).

CONCLUSION

OPG and RANKL may serve as potential markers for assessment of cardiovascular calcification and prediction of the cardiovascular risk status in acromegalic patients.

The Role of the Receptor Activator of Nuclear Factor Kappa-B Ligand/Osteoprotegerin Ratio in Vascular Diseases: A Therapeutic Approach

Cardiovascular and bone diseases contribute independently to mortality and global health. The exact mechanisms involved in the pathophysiology shared between bone and vascular diseases are not well defined. Endothelial cells and osteoblasts communicate during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. One shared mechanism may involve osteoprotegerin (OPG) and its ligand Receptor Activator of NF-κB Ligand (RANKL). The RANKL/OPG ratio is an important modulator for the skeletal, immunological, and vascular systems. OPG levels are elevated due to either osteogenic causes or inflammatory responses in the vasculature. The data obtained from clinical and in vitro studies support the role of the RANKL/OPG ratio as a potential marker for the progression of endothelial damage. Therefore, determining the therapeutic approaches for the targeting RANKL/OPG ratio and evaluating its usage as a biomarker in cardiovascular and bone pathophysiology are needed. By integrating the protective and disease-causing role of OPG with its ligand, this review outlines the role of the RANKL/OPG ratio at the molecular level. We also consider targeted therapeutic approaches.

OPG/RANK/RANKL axis relation to cardiac iron-overload in children with transfusion-dependent thalassemia

OPG/RANK/RANKL axis was reportedly involved in initiating various diseases, especially bone and cardiovascular diseases. This study aimed to assess the relationship between some OPG, RANK, and RANKL polymorphisms and alleles and iron-overload-induced cardiomyopathy in children with transfusion-dependent thalassemia (TDT). This study included 80 TDT children and 80 age and sex-matched controls. Real-time PCR was done for rs207318 polymorphism for the OPG gene and rs1805034, rs1245811, and rs75404003 polymorphisms for the RANK gene, and rs9594782 and rs2277438 polymorphisms for the RANKL gene. Cardiac T2* MRI and ejection fraction (EF) were done to assess the myocardial iron status and cardiac function. In this study, there were no significant differences in frequencies of the studied polymorphisms between cases and controls (p > 0.05 in all). In TDT children, OPG rs2073618 (G > C) had a significant relation to myocardial iron overload (p = 0.02). Its C allele had significantly more frequent normal EF than its G allele (p = 0.04). RANK rs75404403 (C > DEL) had a significant relation to cardiac dysfunction (p = 0.02). Moreover, the C allele of that gene had significantly more frequent affected EF than its DEL allele (p = 0.02). The A allele of RANKL rs2277438 (G > A) had significantly less frequent severe cardiac iron overload than the G allele (p = 0.04). In conclusion, the OPG/ RANK/RANKL genes may act as genetic markers for iron-induced cardiomyopathy in TDT children. Some of the studied genes' polymorphisms and alleles were significantly related to myocardial iron overload and cardiac dysfunction in TDT children.

Decreased 25-Hydroxy Vitamin D Level Is Associated with All-Cause Mortality in Patients with Type 2 Diabetes at High Cardiovascular Risk

Cardiovascular diseases are among the leading causes of morbidity and mortality, particularly in individuals with type 2 diabetes. There is a need for new biomarkers to improve the prediction of cardiovascular events and overall mortality. We investigated the association of selected atherosclerosis related biomarkers, specifically osteoprotegerin (OPG), 25-hydroxy-vitamin D (25(OH)D), C-reactive protein (CRP), lipopolysaccharide-binding protein (LBP), and asymmetric dimethylarginine (ADMA), with the occurrence of any cardiovascular event or all-cause mortality (primary outcome) during a 5.6-year follow-up of 190 patients with type 2 diabetes. Data were analyzed using logistic regression to adjust for baseline cardiovascular status and cardiovascular risk factors. The primary outcome occurred in 89 participants (46.8%) during the study. When analyzed individually, 25(OH)D, CRP, and LBP significantly predicted the primary outcome in multivariable models. However, in a model that included all biomarkers, only a decreased level of 25(OH)D remained a significant predictor of the primary outcome. Moreover, the level of 25(OH)D significantly predicted all-cause mortality: a reduction of 10 ng/mL was associated with a two-fold increase in all-cause mortality. Our study thus demonstrates that vitamin D deficiency was the strongest factor associated with the primary outcome and all-cause mortality after a 5.6-year follow-up in patients with type 2 diabetes at high cardiovascular risk.

Proteomic cardiovascular risk assessment in chronic kidney disease

AIMS

Chronic kidney disease (CKD) is widely prevalent and independently increases cardiovascular risk. Cardiovascular risk prediction tools derived in the general population perform poorly in CKD. Through large-scale proteomics discovery, this study aimed to create more accurate cardiovascular risk models.

METHODS AND RESULTS

Elastic net regression was used to derive a proteomic risk model for incident cardiovascular risk in 2182 participants from the Chronic Renal Insufficiency Cohort. The model was then validated in 485 participants from the Atherosclerosis Risk in Communities cohort. All participants had CKD and no history of cardiovascular disease at study baseline when ∼5000 proteins were measured. The proteomic risk model, which consisted of 32 proteins, was superior to both the 2013 ACC/AHA Pooled Cohort Equation and a modified Pooled Cohort Equation that included estimated glomerular filtrate rate. The Chronic Renal Insufficiency Cohort internal validation set demonstrated annualized receiver operating characteristic area under the curve values from 1 to 10 years ranging between 0.84 and 0.89 for the protein and 0.70 and 0.73 for the clinical models. Similar findings were observed in the Atherosclerosis Risk in Communities validation cohort. For nearly half of the individual proteins independently associated with cardiovascular risk, Mendelian randomization suggested a causal link to cardiovascular events or risk factors. Pathway analyses revealed enrichment of proteins involved in immunologic function, vascular and neuronal development, and hepatic fibrosis.

CONCLUSION

In two sizeable populations with CKD, a proteomic risk model for incident cardiovascular disease surpassed clinical risk models recommended in clinical practice, even after including estimated glomerular filtration rate. New biological insights may prioritize the development of therapeutic strategies for cardiovascular risk reduction in the CKD population.

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.

TRAIL or TRAIL-R2 as a Predictive Biomarker for Mortality or Cardiovascular Events: A Systematic Review and Meta-analysis

ABSTRACT

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and TRAIL-receptor-2 (TRAIL-R2) are associated with atherosclerosis. This meta-analysis aimed to investigate the potential association between TRAIL/TRAIL-R2 with mortality or cardiovascular (CV) events. PubMed, Embase, and Cochrane Library were searched for reports published up to May 2021. Reports were included when the association between TRAIL or TRAIL-R2 and mortality or CV events was reported. Considering the heterogeneity between studies, we used the random-effects model for all analyses. Ultimately, the meta-analysis included 18 studies (16,295 patients). The average follow-up ranged from 0.25 to 10 years. Decreased TRAIL levels were negatively associated with all-cause mortality [rank variable, hazard ratio (HR), 95% CI, 2.93, 1.94-4.42; I2 = 0.0%, Pheterogeneity = 0.835]. Increased TRAIL-R2 levels were positively associated with all-cause mortality (continuous variable, HR, 95% CI, 1.43, 1.23-1.65; I2 = 0.0%, Pheterogeneity = 0.548; rank variable, HR, 95% CI, 7.08, 2.70-18.56; I2 = 46.5%, Pheterogeneity = 0.154), CV mortality (continuous variable, HR, 95% CI, 1.33, 1.14-1.57; I2 = 0.0%, Pheterogeneity = 0.435), myocardial infarction (continuous variable, HR, 95% CI, 1.23, 1.02-1.49; rank variable, HR, 95% CI, 1.49, 1.26-1.76; I2 = 0.7%, Pheterogeneity = 0.402), and new-onset heart failure (rank variable, HR, 95% CI, 3.23, 1.32-7.87; I2 = 83.0%, Pheterogeneity = 0.003). In conclusion, decreased TRAIL was negatively associated with all-cause mortality, and increased TRAIL-R2 was positively associated with all-cause mortality, CV mortality, myocardial infarction, and heart failure.

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.

The association of plasma osteoprotegerin levels and functional outcomes post endovascular thrombectomy in acute ischemic stroke patients: a retrospective observational study

Background

Osteoprotegerin (OPG), also known as osteoclastogenesis inhibitory factor, is a tumor necrosis factor receptor superfamily component. There is an established relationship between OPG and cardiovascular disease. We hypothesized that plasma OPG levels are associated with functional outcomes in acute ischemic stroke patients who have undergone endovascular thrombectomy (EVT).

Methods

From April 2014 through December 2020, a total of 360 acute ischemic stroke patients who underwent EVT were prospectively included in this retrospective observational study. Plasma OPG was measured after fasting for 12 postoperative hours after EVT. A modified Rankin Scale (mRS) was used to assess functional outcomes 3 months after index stroke occurrence. Univariate and multivariate binary logistic regression and ordinal logistic regression analyses were performed to investigate the association of plasma OPG levels with poor functional outcomes.

Results

Overall, 145 (40.2%) patients had poor (mRS > 2) outcomes. The mean ± standard deviation plasma OPG level was 200.2 ± 74.4 pg/mL. Multivariate analysis after adjusting for sex, body mass index, and variables with p < 0.1 in the preceding univariate analysis revealed high plasma OPG levels were independently associated with poor functional outcomes (highest tertile vs. lowest tertile of OPG; odds ratios (OR) 2.121, 95% confidence interval (CI) [1.089-4.191], p = 0.037 in binary logistic regression, OR 2.102, 95% CI [1.301-3.412], p = 0.002 in ordinal logistic regression analysis).

Conclusions

This study demonstrated that higher plasma OPG levels were associated with poor functional outcomes in acute ischemic stroke patients who underwent EVT.

Association Between Serum Selenium Concentration and OPG/RANKL/RANK Axis in Patients with Arterial Hypertension

The aim of the study was to determine the relationship between the serum selenium concentration (Se-S) and the blood concentrations of osteoprotegerin (OPG), receptor activator of nuclear factor kappa-Β ligand (RANKL) and the OPG/RANKL ratio in patients with arterial hypertension. The study group comprised 138 patients with arterial hypertension (age: 56.04 ± 11.59 years). Se-S was determined in all the subjects. Based on the Se-S, the following subgroups were distinguished: a subgroup of patients with a lower Se-S ("low-Se", Se-S < median) and a subgroup of patients with a higher Se-S ("high-Se", Se-S ≥ median). Moreover, the blood concentrations of the parameters of bone metabolism and extraskeletal calcification were assessed: OPG and RANKL. The OPG/RANKL ratio was calculated. In the "low-Se" subgroup, the RANKL concentration was statistically significantly lower, and the OPG/RANKL ratio was statistically significantly higher than in the patients in the "high-Se" subgroup. The correlation analysis showed the negative linear relationships between Se-S and OPG (r = - 0.25, p < 0.05) and between Se-S and OPG/RANKL (r = - 0.47, p < 0.05). Moreover, Se-S positively correlated with RANKL (r = 0.33, p < 0.05). In regression analysis, higher body mass index (BMI), smoking and lower Se-S were independently associated with a higher OPG/RANKL ratio, while lower BMI, use of diuretics, β-blockers and ACE inhibitors and lower OPG/RANKL ratio with effective blood pressure control. In summary, in the group of patients with arterial hypertension, lower Se-S is associated with an unfavourable prognostic panel of parameters of bone metabolism and extraskeletal calcification. Lower Se-S is an independent risk factor for a higher OPG/RANKL ratio, which is an independent prediction factor of ineffective blood pressure control in patients with hypertension.

Hexarelin attenuates abdominal aortic aneurysm formation by inhibiting SMC phenotype switch and inflammasome activation

Hexarelin, a synthetic growth hormone-releasing peptide, is shown to be protective in cardiovascular diseases such as myocardial infraction and atherosclerosis. However, the functional role of hexarelin in abdominal aortic aneurysm (AAA) remains undefined. The present study determined the effect of hexarelin administration (200 μg/kg twice per day) in a mouse model of elastase-induced abdominal aortic aneurysm. Echocardiography and in situ pictures showed hexarelin decreased infrarenal aorta diameter. Histology staining showed elastin degradation was improved in hexarelin-treated group. Hexarelin rescued smooth muscle cell contractile phenotype with increased α-SMA and decreased MMP2. Furthermore, hexarelin inhibited inflammatory cell infiltration, NLRP3 inflammasome activation and IL-18 production. Particularly, hexarelin suppressed NF-κB signaling pathway which is a key initiator of inflammatory response. These results demonstrated that hexarelin attenuated AAA development by inhibiting SMC phenotype switch and NF-κB signaling mediated inflammatory response.

Synthetic Pyridoindole and Rutin Affect Upregulation of Endothelial Nitric Oxide Synthase and Heart Function in Rats Fed a High-Fat-Fructose Diet

Metabolic syndrome (MetS) belongs to the serious health complications expanding in cardiovascular diseases, obesity, insulin resistance, and hyperglycemia. In this study, hypertriacylglycerolemic rats fed a high-fat-fructose diet (HFFD) were used as an experimental model of MetS to explore the effect of tested compounds. Effects of a new prospective pyridoindole derivative coded SMe1EC2 and the natural polyphenol rutin were tested. Endothelial nitric oxide synthase (NOS3) and nuclear factor kappa B (NF-?B) expression were assessed in the left ventricle immunohistochemically and left ventricle activity was monitored in isolated perfused rat hearts. NOS3 activity in the left ventricle decreased markedly as a result of a HFFD. NOS3 expression was upregulated by both substances. NF-?B expression was increased in the MetS group in comparison to control rats and the expression further increased in the SMe1EC2 treatment. This compound significantly improved the coronary flow in comparison to the control group during reperfusion of the heart followed after ischemia. Further, it tended to increase left ventricular systolic pressure, heart product, rate of maximal contraction and relaxation, and coronary flow during baseline assessment. Moreover, the compound SMe1EC2 decreased the sensitivity of hearts to electrically induced ventricular fibrillation. Contrary to this rutin decreased coronary flow in reperfusion. Present results suggest that despite upregulation of NOS3 by both substances tested, pyridoindole SMe1EC2 rather than rutin could be suitable in treatment strategies of cardiovascular disorders in MetS-like conditions.

Association between serum osteoprotegerin level and renal prognosis in nondialysis patients with chronic kidney disease in the Korean Cohort Study for Outcomes in Patients with Chronic Kidney Disease (the KNOW-CKD Study)

Background

Osteoprotegerin is an important regulator of bone metabolism and vascular calcification. The association between serum osteoprotegerin level and chronic kidney disease (CKD) progression has not been elucidated. We investigated the prognostic value of serum osteoprotegerin levels in nondialysis CKD patients.

Methods

We analyzed 2,082 patients enrolled in the Korean Cohort Study for Outcomes in Patients with CKD between 2011 and 2016. Patients were divided into quartiles by their serum osteoprotegerin levels. The primary outcome was the occurrence of ≥1 of the following: dialysis initiation, kidney transplantation, a two-fold increase in serum creatinine level from baseline, or a 50% decrease in the estimated glomerular filtration rate (eGFR). Cox proportional hazard regression models were used to investigate the prognostic value of the serum osteoprotegerin level to CKD progression.

Results

The median follow-up period was 48.9 months, and 641 patients (30.8%) experienced the primary outcome. The hazard ratio of serum osteoprotegerin for renal progression in the full extended Cox proportional hazard model was 1.064 (95% confidence interval, 1.041–1.088). Subgroup analyses by age, presence of diabetes, and eGFR showed significant results consistent with the overall analysis results.

Conclusion

Serum osteoprotegerin level is independently associated with renal prognosis and could have prognostic importance in CKD progression.

Effect of vitamin D supplementation on OPG/RANKL signalling activities in endothelial tissue damage in diet-induced diabetic rat model

BACKGROUND

Type 2 Diabetes Mellitus is a chronic metabolic disease that causes endothelial damage and is an important risk factor for atherosclerosis. In the present study vitamin D3 supplementation in rats was used to determine the role of Osteoprotegerin (OPG)/Receptor activator kB ligand (RANKL) signalling in endothelial damage and changes in the expression levels of genes involved in this pathway. We hypothesized that vitamin D3 supplementation affects OPG and RANKL activity in the aorta.

METHODS

Diabetes was induced in rats via injections of 40 mg/kg of streptozotocin followed by a high fructose (10%) diet. Group 2 (healthy) and 4 (diabetic) received 170 IU/kg of vitamin D3 weekly for 5 weeks, while Group 1 (healthy) and 2 (diabetic) received sterile saline. The aortas of each group were collected to analyse mRNA expression using the real-time PCR method and also to evaluate magnesium and calcium levels using inductively coupled plasma mass spectrometry.

RESULTS

Opg and Il-1b expression levels were significantly associated with both diabetes and vitamin D3 supplementation in the aortas of the study groups (p ≤ 0.05). Opg mRNA expression was also found to correlate with both Icam-1 and Nos3 mRNA expression levels (r = 0.699, p = 0.001 and r = 0.622, p = 0.003, respectively). In addition, when mineral levels in the aortic tissues were compared among all groups, it was found that the interaction of diabetes and vitamin D3 supplementation significantly affected Mg levels and Mg/Ca ratios.

CONCLUSIONS

It is concluded that vitamin D3 supplementation has a modulatory effect on OPG/RANKL activity in the vessel wall by ameliorating endothelial damage in diabetes. This effect may contribute to the regulation of cytokine-mediated vascular homeostasis and mineral deposition in the aorta; therefore, further comprehensive studies are proposed to demonstrate this relationship.

The cross-talk between matrix metalloproteinase-9, RANKL/OPG system and cardiovascular risk factors in ovariectomized rat model of postmenopausal osteoporosis

Epidemiology and pathogenesis of cardiovascular diseases (CVD) and osteoporosis are strikingly overlapping. This study presents matrix metalloproteinase-9 (MMP-9), as a simple molecular link more consistently associated with the pathophysiology of both osteoporosis and CVD risk factors. 40 adult female rats were randomly distributed into 4 groups [control sham-operated, untreated osteoporosis, carvedilol-treated osteoporosis and alendronate-treated osteoporosis]. After 8 weeks, blood samples were collected to estimate Lipid profile (Total cholesterol, HDL, Triglycerides), inflammatory markers (IL-6, TNF alpha, CRP and NO), and Bone turnover markers (BTM) (Alkaline phosphatase, osteocalcin and pyridinoline). The tibias were dissected to estimate MMP-9 and NF-kB gene expression, OPG, RANKL levels and for histological examination. Induction of osteoporosis resulted in a significant elevation in BTM, inflammatory markers and dyslipidemia. MMP-9 was significantly elevated and positively correlated with BTM, inflammation and dyslipidemia markers. Carvedilol and alendronate exerted a bone preservative role and attenuated dyslipidaemia and inflammation in accordance with their respective effect on MMP-9.

Association between Serum Osteoprotegerin Levels and Severity of Coronary Artery Disease in Patients with Acute Myocardial Infarction

Background. Osteoprotegerin (OPG), a glycoprotein of the tumour necrosis factor (TNF) superfamily, is one of the main biomarkers for vascular calcification. Aim. We aimed to evaluate the association between serum OPG levels and extent of coronary lesions in patients with acute myocardial infarction (MI). Methods. Consecutive patients hospitalized for an acute MI who underwent coronary angiography were included. SYNTAX score was calculated to assess the severity of coronary artery disease. The population was analysed in low (5 (3–6)), medium (11 (9–13)) and high (20 (18–23)) tertiles of SYNTAX score. Results. Among the 378 patients included, there was a gradual increase in age, rate of diabetes, anterior wall location, and a reduction in left ventricular ejection fraction across the SYNTAX tertiles. OPG levels significantly increased across the tertiles (962 (782–1497), 1240 (870–1707), and 1464 (1011–2129) pg/mL, respectively (p < 0.001)). In multivariate analysis, OPG [OR(CI95%): 2.10 (1.29–3.49) 0.003], were associated with the high SYNTAX group, beyond hypercholesterolemia, CV history and reduced glomerular filtration rate. Conclusion. We found an association between OPG levels and coronary lesions complexity patients with acute MI.

High levels of osteoprotegerin are associated with coronary artery calcification in patients suspected of a chronic coronary syndrome

Plasma osteoprotegerin (OPG) and vascular smooth muscle cell (VSMC) derived extracellular vesicles (EVs) are important regulators in the process of vascular calcification (VC). In population studies, high levels of OPG are associated with events. In animal studies, however, high OPG levels result in reduction of VC. VSMC-derived EVs are assumed to be responsible for OPG transport and VC but this role has not been studied. For this, we investigated the association between OPG in plasma and circulating EVs with coronary artery calcium (CAC) as surrogate for VC in symptomatic patients. We retrospectively assessed 742 patients undergoing myocardial perfusion imaging (MPI). CAC scores were determined on the MPI-CT images using a previously developed automated algorithm. Levels of OPG were quantified in plasma and two EV-subpopulations (LDL and TEX), using an electrochemiluminescence immunoassay. Circulating levels of OPG were independently associated with CAC scores in plasma; OR 1.39 (95% CI 1.17–1.65), and both EV populations; EV-LDL; OR 1.51 (95% CI 1.27–1.80) and EV-TEX; OR 1.21 (95% CI 1.02–1.42). High levels of OPG in plasma were independently associated with CAC scores in this symptomatic patient cohort. High levels of EV-derived OPG showed the same positive association with CAC scores, suggesting that EV-derived OPG mirrors the same pathophysiological process as plasma OPG.

Biomarker profiles in obesity patients and their relation to cardiac dysfunction

Aim: Current knowledge on the role of obesity in causing cardiac dysfunction is insufficient. Several biomarkers reflecting biological processes that may play a role in the occurrence of cardiac dysfunction in obesity patients are available. Purpose: To compare cardiovascular biomarker profiles between obesity patients and nonobese controls, and between obesity patients with and without cardiac dysfunction, in order to better understand the underlying pathophysiology of cardiac dysfunction in obesity patients. Materials & methods: Blood samples were obtained from 100 obesity patients (BMI ≥35 kg/m²) without known cardiovascular disease, and from 50 age- and gender-matched nonobese controls (BMI ≤30 kg/m²). The third cardiovascular panel of the Olink Multiplex platform was used for the measurement of 92 biomarkers. Results: The majority (53%) of biomarkers were elevated in obesity patients compared with nonobese controls. Only 5% of the biomarkers were elevated in obesity patients with cardiac dysfunction compared with those without. Biomarkers discriminating cardiac dysfunction from no cardiac dysfunction in obesity patients differed from those discriminating obese from nonobese patients. An elastic net model for the prediction of cardiac dysfunction in obesity patients had a high area under the receiver operating curve of 0.87 (95% CI: 0.79-0.94; p < 0.001). The sensitivity of this model was 84% and the specificity was 79%. Conclusion: A multiplex immunoassay was used for the first time in obesity patients without known cardiovascular disease. These patients have cardiovascular biomarker profiles that are clearly different from nonobese controls. Comparison of obesity patients with and without cardiac dysfunction suggested an important role for inflammation, atherosclerosis and insulin resistance in the underlying pathophysiology of cardiac dysfunction in obesity patients.

Mechanisms of altered bone remodeling in children with type 1 diabetes

Bone loss associated with type 1 diabetes mellitus (T1DM) begins at the onset of the disease, already in childhood, determining a lower bone mass peak and hence a greater risk of osteoporosis and fractures later in life. The mechanisms underlying diabetic bone fragility are not yet completely understood. Hyperglycemia and insulin deficiency can affect the bone cells functions, as well as the bone marrow fat, thus impairing the bone strength, geometry, and microarchitecture. Several factors, like insulin and growth hormone/insulin-like growth factor 1, can control bone marrow mesenchymal stem cell commitment, and the receptor activator of nuclear factor-κB ligand/osteoprotegerin and Wnt-b catenin pathways can impair bone turnover. Some myokines may have a key role in regulating metabolic control and improving bone mass in T1DM subjects. The aim of this review is to provide an overview of the current knowledge of the mechanisms underlying altered bone remodeling in children affected by T1DM.

Analgesic and anti-inflammatory potential of Lupeol isolated from Indian traditional medicinal plant Crateva adansonii screened through in vivo and in silico approaches

Background

Lupeol, a triterpene bioactive compound isolated from Indian traditional plant Crateva adansonii acted as promising and alternative anti-inflammatory agent to treatments of diseases related to inflammation. The inflammatory process in the body serves an important function in the control and repair of injury. However, it is self-perpetuating in number of disease conditions, which must be prevented and treated. Worldwide most prescribing NASID drug shows severe side effects. Whereas drug from natural origin shows dual inhibition of inflammatory and analgesic target protein with more efficacy and less side effects than NSAID drugs. Our study aims to isolate and screen the analgesic and anti-inflammatory potential of lupeol, a pentacyclic triterpenoid isolated from leaf extract of Crateva adansonii belongs to Capparaceae family commonly used Indian traditional medicine for treating inflammatory diseases.

Results

Methanol and chloroform leaf extracts (ME and CE) and lupeol fraction (LF) of plant Crateva adansonii is investigated through employing in vivo male Wistar albino rat model. Acute toxicity study of C. adansonii ME and CE leaf extracts reveals that no mortality and no behavioral changes in experimental animals up to 2 g/kg. So no lethal dose we consider two optimal doses 200 and 400 mg of plant leaf extracts for in vivo inflammatory and analgesic study. In vivo acute and chronic anti-inflammatory activity was carried out through carrageenan-induced rat paw edema and cotton pellet-induced granuloma models. LF (100 mg/kg, oral route) of Crateva adansonii evoked highest percentage of inflammation inhibition (50 and 33.96% respectively) in both in vivo acute and chronic inflammation model among all tested samples (ME and CE 200 mg and 400 mg/kg, oral route) including reference standard (10 mg/kg, oral route) indomethacin. Carrageenan-challenged experimental animals were screened for one inflammatory marker enzyme myeloperoxidase (MPO), inflammatory products such as Prostaglandrin E₂ (PGE₂), and eight different cytokines markers (TNFα, IL-6, IFN γ, IL-1α, IL-1β, MCP-1, Rantes, and MIP) associated with inflammation reveals that LF (100 mg/kg, oral route) of Crateva adansonii shows prominent anti-inflammatory activity than reference standard indomethacin (10 mg/kg, oral route) over all these biological tested parameters. In vivo analgesic assays such as hot plate assay and acetic acid-induced writhing assay revealed that LF (100 mg/kg, oral route) possesses significant analgesic activity (11.60 s and 69.05%) when compared with standard drug pentazocine(10 mg/kg, oral route). Finally, we made an in silico screening of lupeol against analgesic (nAChR) and anti-inflammatory (COX-2) target proteins reveals that lupeol possess highest binding affinity with nAChR and COX-2 target proteins (− 8.5 and − 9.0 Kcal/mol) over the reference standard pentazocine and indomethacin (− 7.0 and − 8.4 Kcal/mol) respectively.

Conclusion

The present study result provides a pharmacological evidences for analgesic and anti-inflammatory potential of lupeol isolated from Indian traditional plant Crateva adansonii act as a multi-target agent with immense anti-inflammatory potential targeting key molecules of inflammation such as MPO, PGE₂, and eight pro-inflammatory cytokine markers. Outcome of present study is to find promising anti-inflammatory bioactive agents from the cheapest Indian traditional medicinal plant sources useful for pharmaceutical industries.

High Cardiovascular Risk in Older Men with Poor Bone Microarchitecture-The Prospective STRAMBO Study

Data on the association between bone microarchitecture and cardiovascular disease (CVD) in men are scarce. We studied the link of bone microarchitecture and areal bone mineral density (aBMD) with the risk of major adverse coronary event (MACE) in a cohort of men aged 60 to 87 years followed prospectively for 8 years. At baseline, aBMD was measured using a Hologic Discovery-A device. Bone microarchitecture was assessed at distal radius and tibia by high-resolution peripheral quantitative computed tomography (XtremeCT Scanco device). During the study, 53 men had incident MACE. The analyses were adjusted for confounders related to bone and CVD. In 813 men (53 MACEs), higher aBMD at the lumbar spine, hip, whole body, and radius was associated with lower risk of MACE (hazard ratio [HR] = 0.44-0.71/SD, p < .025 to < .001). In 745 men having valid distal radius scan (47 MACEs), higher cortical density (Ct.BMD) and higher cortical thickness (Ct.Th^d ) were associated with lower risk of MACE. This risk was higher in men in the lowest quintile of cortical measures versus the four upper quintiles combined (Ct.BMD: HR = 2.12, 95% confidence interval [CI] 1.08-4.17, p < .025). Findings were similar in 779 men having valid distal tibia scan (48 MACEs). At both sites, higher estimated stiffness and higher failure load were associated with a lower risk of MACE. The risk of MACE was higher in men in the lowest quintile of the measures of bone strength versus four upper quintiles jointly (distal radius stiffness: HR = 2.46, 95% CI 1.27-4.74, p < .01). Similar results were obtained in 638 men without prior fragility fracture and in 689 men without ischemic heart disease at baseline. Thus, in older men followed prospectively for 8 years, higher aBMD, preserved cortical bone status, and higher estimated bone strength were associated with lower risk of MACE after adjustment for relevant confounders. © 2021 American Society for Bone and Mineral Research (ASBMR).

Lipid Profile and Vascular Remodelling in Young Dyslipidemic Subjects Treated with Nutraceuticals Derived from Red Yeast Rice

BACKGROUND AND AIMS

A relevant role is emerging for functional foods in cardiovascular prevention. The aim of this study was to assess the effect of a nutraceutical multitargeted approach on lipid profile and inflammatory markers along with vascular remodelling in a cohort of dyslipidemic subjects without history of cardiovascular (CV) disease.

METHODS AND RESULTS

We enrolled 25 subjects (mean age 48.2 years) with low to moderate CV risk profile and total cholesterol (TC) levels between 150 and 250 mg/dl. The patients were assigned to receive for one year a tablet/die of a nutraceutical combination containing red yeast rice (RYR) extract (Monacolin 3 mg/tablet) and coenzyme Q10 (30 mg/tablet). Treatment with the nutraceutical compounds led to a significant reduction of TC (from 227 to 201 mg/dl, p < 0.001), LDL-c (from 150 to 130 mg/dl, p = 0.001), triglycerides (from 121 to 109 mg/dl, p = 0.013), non-HDL-cholesterol (from 168 to 141 mg/dl, p < 0.001), hs-CRP (from 1.74 to 1.20 mg/l, p = 0.015), and osteoprotegerin (from 1488 to 1328 pg/ml, p = 0.045). Levels of HDL-c, Lp(a), glucose, liver enzyme, CPK, or creatinine did not change over time. An ultrasound study was performed to assess changes in mean carotid intima-media thickness (IMT) and maximum IMT (M-MAX) as well as modification in local carotid stiffness by means of determining the carotid compliance coefficient (CC) and distensibility coefficient (DC). At the end of the treatment, we observed small but significant reductions in both mean-IMT (from 0.62 to 0.57 mm, p = 0.022) and M-MAX (from 0.79 to 0.73 mm, p = 0.002), and an improvement in carotid elasticity (DC from 22.4 to 24.3 × 10-3/kPa, p = 0.006 and CC from 0.77 to 0.85 mm2/kPa, p = 0.019).

CONCLUSIONS

A long-term treatment with a combination of RYR and coenzyme Q10 showed lipid-lowering activity along with a reduction of inflammatory mediators and an improvement of vascular properties in young subjects with a low-to-moderate CV risk profile.

TRAIL and Cardiovascular Disease-A Risk Factor or Risk Marker: A Systematic Review

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a pro-apoptotic protein showing broad biological functions. Data from animal studies indicate that TRAIL may possibly contribute to the pathophysiology of cardiomyopathy, atherosclerosis, ischemic stroke and abdominal aortic aneurysm. It has been also suggested that TRAIL might be useful in cardiovascular risk stratification. This systematic review aimed to evaluate whether TRAIL is a risk factor or risk marker in cardiovascular diseases (CVDs) focusing on major adverse cardiovascular events. Two databases (PubMed and Cochrane Library) were searched until December 2020 without a year limit in accordance to the PRISMA guidelines. A total of 63 eligible original studies were identified and included in our systematic review. Studies suggest an important role of TRAIL in disorders such as heart failure, myocardial infarction, atrial fibrillation, ischemic stroke, peripheral artery disease, and pulmonary and gestational hypertension. Most evidence associates reduced TRAIL levels and increased TRAIL-R2 concentration with all-cause mortality in patients with CVDs. It is, however, unclear whether low TRAIL levels should be considered as a risk factor rather than a risk marker of CVDs. Further studies are needed to better define the association of TRAIL with cardiovascular diseases.

The role of the RANKL/RANK/OPG system in the central nervous systems (CNS)

The receptor-activator of NF-κB ligand (RANKL) and its specific receptor RANK have essential roles in regulating bone metabolism and the immune system. Besides, the RANKL/RANK system plays important roles in multiple physiological and pathophysiological processes such as mammary gland development during pregnancy, cancer development, and bone metastasis. While it has long been known that RANKL and RANK are expressed in the central nervous system (CNS), the physiological roles of RANKL/RANK system in the CNS and the underlying molecular mechanisms have been elucidated recently. Over the last decade, several reports showed that the central RANKL/RANK system plays important roles in regulating body temperature, brain ischemia, autoimmune encephalopathy, feeding behavior, and energy metabolism. In this review, it is provided an updated information regarding the roles of RANKL/RANK system in the CNS.

The role of osteoprotegerin in the development, progression and management of abdominal aortic aneurysms

Osteoprotegerin (OPG) appears to be a very promising marker both in the diagnosis of abdominal aortic aneurysms (AAAs) and as a potential target in its treatment. This article presents an overview of the current literature that discusses the role of OPG in the pathogenesis of atherosclerosis and its potential value as a prognostic factor in AAA. Pharmacological modulation of OPG expression has been considered. In conclusion, it seems that further research designed to assess the relationship between OPG and AAA is needed as this may contribute to improved AAA monitoring and more effective treatment of patients with AAA.

Osteoprotegerin and Osteopontin Serum Levels are Associated with Vascular Function and Inflammation in Coronary Artery Disease Patients

BACKGROUND

Osteoprotegerin and osteopontin have recently emerged as key factors in both vascular remodelling and atherosclerosis progression. Interleukin-6 (IL-6) is an inflammatory cytokine with a key role in atherosclerosis. The relationship of osteoprotegerin, osteopontin, and IL-6 serum levels with endothelial function and arterial stiffness was evaluated in patients with coronary artery disease (CAD).

METHODS

We enrolled 219 patients with stable CAD and 112 control subjects. Osteoprotegerin, osteopontin and IL-6 serum levels were measured using an ELISA assay. Endothelial function was evaluated by flow-mediated dilation (FMD) in the brachial artery and carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness.

RESULTS

There was no significant difference between control subjects and CAD patients according to age and sex. Compared with control subjects, CAD patients had significantly impaired FMD (p<0.001) and increased PWV (p=0.009). CAD patients also had significantly higher levels of osteoprotegerin (p<0.001), osteopontin (p<0.001) and IL-6 (p=0.03), compared with control subjects. Moreover, IL-6 levels were correlated with osteoprotegerin (r=0.17, p=0.01) and osteopontin (r=0.30, p<0.001) levels. FMD was correlated with osteoprotegerin levels independent of possible confounders [b coefficient= - 0.79, 95% CI (-1.54, -0.05), p=0.04].

CONCLUSION

CAD patients have increased osteoprotegerin, osteopontin and IL-6 levels. Moreover, there is a consistent association between osteoprotegerin and osteopontin serum levels, vascular function and inflammation in CAD patients. These findings suggest another possible mechanism linking osteoprotegerin and osteopontin serum levels with CAD progression through arterial wall stiffening and inflammation.

Association of the Serum Osteoprotegerin Level With Target Organ Damage in Patients at High Risk of Coronary Artery Disease

BACKGROUND

There is little data as to whether osteoprotegerin (OPG) is associated with target organ damage (TOD), so we evaluated the association in patients at high risk of coronary artery disease (CAD).Methods and Results:A total of 349 patients who underwent invasive coronary angiography (ICA) for suspected CAD were prospectively recruited. During the index admission, 6 TOD parameters were collected: extent of CAD, glomerular filtration rate (GFR), left ventricular mass index (LVMI), E/e', brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI). Serum OPG levels were measured using enzyme-linked immunosorbent assay. The OPG level was significantly higher in patients with ≥1 TOD parameter than in those without (314±186 vs. 202±74 pg/mL, P<0.001). For each TOD parameter, the serum OPG level was significantly higher in patients with TOD than in those without (P<0.05 for each) except for ABI. In correlation analysis, OPG was significantly associated with GFR, LVMI, E/e', baPWV and ABI (P<0.05 for each). The OPG concentration increased proportionally with increasing TOD (P<0.001). Higher OPG concentrations (≥198 pg/mL) was significantly associated with the presence of TOD (odds ratio 3.22; 95% confidence interval 1.51-6.85; P=0.002) even after controlling for potential confounders.

CONCLUSIONS

Serum OPG level was significantly associated with a variety of TOD in patients undergoing ICA. OPG may be a useful marker for TOD and in the risk stratification of patients at high risk of CAD.

A missense mutation sheds light on a novel structure-function relationship of RANKL

The tumor necrosis factor (TNF)-like core domain of receptor activator of nuclear factor-κB ligand (RANKL) is a functional domain critical for osteoclast differentiation. One of the missense mutations identified in patients with osteoclast-poor autosomal recessive osteopetrosis (ARO) is located in residue methionine 199 that is replaced with lysine (M199K) amid the TNF-like core domain. However, the structure-function relationship of this mutation is not clear. Sequence-based alignment revealed that the fragment containing human M199 is highly conserved and equivalent to M200 in rat. Using site-directed mutagenesis, we generated three recombinant RANKL mutants M200K/A/E (M200s) by replacing the methionine 200 with lysine (M200K), alanine (M200A), and glutamic acid (M200E), representative of distinct physical properties. TRAcP staining and bone pit assay showed that M200s failed to support osteoclast formation and bone resorption, accompanied by impaired osteoclast-related signal transduction. However, no antagonistic effect was found in M200s against wild-type rat RANKL. Analysis of the crystal structure of RANKL predicted that this methionine residue is located within the hydrophobic core of the protein, thus, likely to be crucial for protein folding and stability. Consistently, differential scanning fluorimetry analysis suggested that M200s were less stable. Western blot analysis analyses further revealed impaired RANKL trimerization by M200s. Furthermore, receptor-ligand binding assay displayed interrupted interaction of M200s to its intrinsic receptors. Collectively, our studies revealed the molecular basis of human M199-induced ARO and elucidated the indispensable role of rodent residue M200 (equivalent to human M199) for the RANKL function.

Elevated Osteoprotegerin Concentration Predicts Increased Risk of Cardiovascular Mortality in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

Studies have shown inconsistent results regarding the association between osteoprotegerin (OPG) concentration and cardiovascular mortality in patients with chronic kidney disease (CKD). This systematic review and meta-analysis aims to investigate the association between OPG concentration and cardiovascular mortality in patients with CKD.

METHODS

Between January 1970 and February 2020, the PubMed, EMBASE, and Cochrane Library databases were searched for eligible studies investigating the association between OPG concentration and cardiovascular mortality in patients with CKD. Pooled hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were calculated using random effects models.

RESULTS

In total, 10 studies comprising 2,120 patients (including 1,723 receiving dialysis) with CKD were included. The included studies were considered to be of fair to high quality. Patients in the highest OPG concentration group had a significantly higher risk of cardiovascular mortality (4 studies; adjusted HR, 2.05; 95% CI, 1.39-3.00) than patients in the low OPG concentration group. An increase of 1 pmol/L in OPG concentration was associated with a 4% increased risk of cardiovascular mortality (6 studies; adjusted HR, 1.04; 95% CI, 1.02-1.07).

CONCLUSION

Elevated OPG concentrations are associated with an increased risk of cardiovascular death in patients with CKD.

Vasculoprotective Effects of Vildagliptin. Focus on Atherogenesis

Vildagliptin is a representative of Dipeptidyl Peptidase-4 (DPP-4) inhibitors, antihyperglycemic drugs, approved for use as monotherapy and combination therapy in type 2 diabetes mellitus. By inhibiting enzymatic decomposition, DPP-4 inhibitors increase the half-life of incretins such as GLP-1 (Glucagon-like peptide-1) and GIP (Gastric inhibitors polypeptide) and prolong their action. Some studies present results suggesting the anti-sclerotic and vasculoprotective effects of vildagliptin reaching beyond glycemic control. Vildagliptin is able to limit inflammation by suppression of the NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling pathway and proinflammatory agents such as TNF-α (tumor necrosis factor α), IL-1β (Interleukin-1β), and IL-8 (Interleukin 8). Moreover, vildagliptin regulates lipid metabolism; attenuates postprandial hypertriglyceridemia; and lowers serum triglycerides, apolipoprotein B, and blood total cholesterol levels. This DPP-4 inhibitor also reduces macrophage foam cell formation, which plays a key role in atheromatous plaque formation and stability. Vildagliptin reduces vascular stiffness via elevation of nitric oxide synthesis, improves vascular relaxation, and results in reduction in both systolic and diastolic blood pressure. Treatment with vildagliptin lowers the level of PAI-1 presenting possible antithrombotic effect. By affecting the endothelium, inflammation, and lipid metabolism, vildagliptin may affect the development of atherosclerosis at its various stages. The article presents a summary of the studies assessing vasculoprotective effects of vildagliptin with special emphasis on atherogenesis.

Comprehensive assessment of tissue and serum parameters of bone metabolism in a series of orthopaedic patients

Bone diseases represent an increasing health burden worldwide, and basic research remains necessary to better understand the complexity of these pathologies and to improve and expand existing prevention and treatment approaches. In the present study, 216 bone samples from the caput femoris and collum femoris of 108 patients with degenerative or dysplastic coxarthrosis, hip fracture, or osteonecrosis were evaluated for the proportion of trabecular bone (TB) and expression of parathyroid hormone (PTH) type 1 receptor (PTH1R), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL). Serum levels of PTH, OPG, soluble RANKL (sRANKL), alkaline phosphatase (AP), osteocalcin, total procollagen type-1 intact N-terminal propeptide (TP1NP), tartrate-resistant acid phosphatase type 5b (TRAP5b), sclerostin, and C-telopeptide of type-1 collagen (ICTP) were also determined. Age was positively correlated with serum levels of PTH, OPG, and sclerostin but negatively associated with TB and sRANKL. Women exhibited less TB, lower sclerostin and ICTP, and higher TRAP5b. Impaired kidney function was associated with shorter bone decalcification time, less TB, lower sRANKL, and higher serum PTH, OPG, and sclerostin. Furthermore, correlations were observed between bone PTH1R and OPG expression and between serum PTH, OPG, and AP. There were also positive correlations between serum OPG and TP1NP; serum OPG and sclerostin; serum AP, osteocalcin, and TRAP5b; and serum sclerostin and ICTP. Serum OPG was negatively associated with sRANKL. In summary, clear relationships between specific bone metabolism markers were observed, and distinct influences of age, sex, and kidney function, thus underscoring their suitability as diagnostic or prognostic markers.

OPG/RANK/RANKL signaling axis in patients with type I diabetes: Associations with parathormone and vitamin D

BACKGROUND

Type 1 diabetes (T1D) has been associated with a higher fracture risk due to alterations in bone structure and metabolism. On the other hand, the important role of the RANKL/OPG/RANK signaling axis in bone physiology is well established. The aim of this study was to evaluate the levels of receptor activator of nuclear factor kappa-B ligand (RANKL), receptor activator of nuclear factor kappa-B (RANK) and plasma osteoprotegerin (OPG) levels, in T1D youngsters and to investigate factors that could influence the OPG/RANK/RANKL signaling axis such as 25-hydroxy vitamin D [25(OH) D], parathormone (PTH) and age.

METHODS

Serum RANKL, RANK, 25(OH) D, PTH levels and plasma OPG levels, were measured in 71 youngsters with T1D and 50 healthy controls matched for age and gender.

RESULTS

Plasma OPG levels were significantly lower (p = 0.025) in T1D patients compared to controls. Serum RANKL levels were significantly higher (p = 0.037), while no differences were observed in serum RANK levels (p = 0.946) between the two groups. Serum 25(OH) D levels found significantly decreased (p < 0.001) while serum PTH levels were significantly elevated (p < 0.001) in T1D patients than in controls.

CONCLUSIONS

Our results demonstrated that OPG and RANKL may be promising biomarkers for T1D patients. However, their circulating levels were associated with several factors including PTH, 25(OH) D and therefore, may represent an integrative biomarker for a variety of endocrine signaling disturbances observed in T1D.

BONE MARKERS IN ARTHROPATHIES

Bone endures a lifelong course of construction and destruction, with bone marker (BM) molecules released during this cycle. The field of measuring BM levels in synovial fluid and peripheral blood is a cardinal part of bone research within modern clinical medicine and has developed extensively in the last years. The purpose of our work was to convey an up-to-date overview on synovial fluid and serum BMs in the most common arthropathies.

Clinical Inference of Serum and Bone Sclerostin Levels in Patients with End-Stage Kidney Disease

Mounting evidence indicates that sclerostin, a well-known inhibitor of bone formation, may qualify as a clinically relevant biomarker of chronic kidney disease-related mineral and bone disorder (CKD-MBD), including abnormal mineral and bone metabolism and extraskeletal calcification. For this purpose, in this study we investigate the extent to which circulating sclerostin, skeletal sclerostin expression, bone histomorphometric parameters, and serum markers of bone metabolism associate with each other. Bone biopsies and serum samples were collected in a cohort of 68 end-stage kidney disease (ESKD) patients. Serum sclerostin levels were measured using 4 different commercially available assays. Skeletal sclerostin expression was evaluated on immunohistochemically stained bone sections. Quantitative bone histomorphometry was performed on Goldner stained tissue sections. Different serum markers of bone metabolism were analyzed using in-house techniques or commercially available assays. Despite large inter-assay differences for circulating sclerostin, results obtained with the 4 assays under study closely correlated with each other, whilst moderate significant correlations with skeletal sclerostin expression were also found. Both skeletal and circulating sclerostin negatively correlated with histomorphometric bone and serum parameters reflecting bone formation and turnover. In this study, the unique combined evaluation of bone sclerostin expression, bone histomorphometry, bone biomarkers, and serum sclerostin levels, as assessed by 4 different assays, demonstrated that sclerostin may qualify as a clinically relevant marker of disturbed bone metabolism in ESKD patients.

Low bone mass is associated with carotid calcification plaque in Chinese postmenopausal women: the Chongqing osteoporosis study

Background: The aim of this study was to examine the relationship between low bone mass and the risk of carotid calcification plaques in Chinese postmenopausal women.Methods: We conducted a 5 years prospective study. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) scanning. Carotid computed tomography angiography (CTA) was conducted using a 64-multidetector row scanner to assess carotid arterial plaque at baseline and during follow-up. Cox proportional hazards analysis was used to evaluate the association of BMD and risk of carotid calcification plaques.Results: Four hundred and eighty-eight women sustained prospective carotid plaques during the follow-up. Women with carotid calcification plaques had low BMD than those with carotid non-calcification plaques. After adjustment for potential confounders, BMD, age, years since menopause, levels of plasma osteoprotegerin and adiponectin, hypertension, diabetes mellitus and hyperlipidemia were independently associated with increased risk of carotid calcification plaques. For carotid calcification plaques, a significant inverse correlation was indicated between BMD and the plaques, and a significant positive correlation was indicated between bone loss and plaques.Conclusions: This study suggested that lower BMD and increased loss rate of BMD were associated with a higher risk of carotid calcification plaques in Chinese postmenopausal women.

Bone mass density and bone metabolism marker are associated with progression of carotid and cardiac calcified plaque in Chinese elderly population

Osteoporosis and cardiovascular diseases often coexist in the same elderly individuals. Does this suggest some potential correlation between the two diseases? Low bone mass and change of bone biomarker are associated with a higher risk of carotid and cardiac calcification plaques.

INTRODUCTION

Bone mineral density (BMD) and bone metabolism marker may contribute to the progression of carotid and cardiac arterial calcifications. The aim of this study was to investigate whether low bone mass and the change of bone biomarker are associated with the prevalence of calcified atherosclerotic plaque in elderly Chinese.

METHODS

We conducted a five-year prospective study. BMD was measured by dual-energy X-ray absorptiometry scanning. Carotid and cardiac computed tomography angiography (CTA) was conducted using a 64-multidetector row scanner to assess carotid and cardiac arterial plaque at baseline and during follow-up.

RESULTS

Of 1571 community residents over 60 years of age, 184 (11.7%) subjects developed carotid calcified plaque, 510 (32.5%) subjects developed cardiac calcified plaque and 97 (6.2%) subjects developed co-existence calcified plaques in carotid and cardiac arteries. After adjustment for age and all relevant confounders, Q1, Q2 quartile of BMD, and osteoprotegerin (OPG), osteocalcin (OC), and C-terminal cross-linked telopeptide of type I collagen (CTX) were associated with increased risk of calcified plaques.

CONCLUSION

This study suggested that lower BMD and change of bone metabolism biomarker were associated with a higher risk of carotid and cardiac calcified plaque development.

Correlations between Vascular Stiffness Indicators, OPG, and 25-OH Vitamin D3 Status in Heart Failure Patients

Background and objectives: The purpose of the study is to correlate vascular calcification biomarkers osteoprotegerin (OPG) and 25-hydroxyvitamin D₃ (25-OH-D₃), indicators of arterial stiffness carotid-femoral pulse wave velocity (c-f PWV) and renal resistive index (RRI), with parameters of left ventricular function in heart failure patients versus control. Materials and methods: Our case-control study compared 60 patients with ischemic heart failure and reduced left ventricular ejection fraction (LVEF) (<40%) with a control group of 60 healthy age-matched subjects (CON). Serum levels of OPG and 25-OH-D₃ were determined by ELISA. Left ventricular volumes (LVESV, LVEDV) and LVEF were measured by echocardiography. C-f PWV was determined using the arteriograph device. RRI was measured by duplex Doppler. Peak systolic velocity (PSV) and minimum end-diastolic velocity (EDV) were determined using angle correction. The estimated glomerular filtration rate (eGFR) was calculated using the MDRD equation. The Pearson’s correlation coefficient was used for interpretation of results. Results: OPG values were significantly higher in heart failure (HF) patients vs. CON (4.7 ± 0.25 vs. 1.3 ± 0.67 ng/mL, p < 0.001). 25-OH vitamin D₃ levels were significantly lower in HF patients vs. CON (20.49 ± 7.31 vs. 37.09 ± 4.59 ng/mL, p < 0.001). Multiple regression analysis considering 25-OH D3 as a dependent variable demonstrated indicators of vascular stiffness RRI, c-f PWV and vascular calcification biomarker OPG as predictors. OPG values were significantly correlated with cardiac parameters LVEDV (r = 0.862, p < 0.001), LVEF (r = −0.832, p < 0.001), and c-f PWV(r = 0.833, p < 0.001), and also with 25-OH-D₃ (r = −0.636, p < 0.001). RRI values were significantly correlated with cardiac parameters LVEDV (r = 0.586, p < 0.001) and LVEF (r = −0.587, p < 0.001), and with eGFR (r = −0.488, p < 0.001), c-f PWV(r = 0.640, p < 0.001), and 25-OH-D₃ (r = −0.732, p < 0.001). Conclusions: This study showed significant correlations between vitamin D deficit and vascular stiffness indicators in heart failure patients with reduced ejection fraction, demonstrating the importance of these examinations for a better evaluation of these patients. Together with the evaluation of renal function, the measurement of vascular stiffness indicators and biomarkers might play a key role in identifying patients at greater risk for worsening disease prognosis and for shorter life expectancy, who could benefit from vitamin D supplementation. The abstract was accepted for presentation at the Congress of the European Society of Cardiology, Munich, 2018.

Osteoprotegerin and osteopontin levels, but not gene polymorphisms, predict mortality in cardiovascular diseases

Aim: This study aims to investigate whether osteoprotegerin (OPG) or osteopontin (OPN) single nucleotide polymorphisms (SNPs) will predict survival. Materials & methods: This study enrolled 617 participants undergoing health examination, 536 coronary artery disease (CAD) patients and 86 peripheral artery disease (PAD) patients. Genotypes of OPG SNP rs2073618 and OPN SNP rs11730582 were determined. OPG and OPN levels were measured. Results: In both CAD and PAD populations, high OPG and OPN levels were strong predictors of all-cause death. The OPG rs2073618 CC genotype and the OPN rs11730582 TT genotype did not predict mortality. Conclusion: High OPG and high OPN levels, but not OPG rs2073618 CC genotype or OPN rs11730582 TT genotype, were strong predictors of mortality in both CAD and PAD patients.

TRAIL, OPG, and TWEAK in kidney disease: biomarkers or therapeutic targets?

Ligands and receptors of the tumor necrosis factor (TNF) superfamily regulate immune responses and homeostatic functions with potential diagnostic and therapeutic implications. Kidney disease represents a global public health problem, whose prevalence is rising worldwide, due to the aging of the population and the increasing prevalence of diabetes, hypertension, obesity, and immune disorders. In addition, chronic kidney disease is an independent risk factor for the development of cardiovascular disease, which further increases kidney-related morbidity and mortality. Recently, it has been shown that some TNF superfamily members are actively implicated in renal pathophysiology. These members include TNF-related apoptosis-inducing ligand (TRAIL), its decoy receptor osteoprotegerin (OPG), and TNF-like weaker inducer of apoptosis (TWEAK). All of them have shown the ability to activate crucial pathways involved in kidney disease development and progression (e.g. canonical and non-canonical pathways of the transcription factor nuclear factor-kappa B), as well as the ability to regulate cell proliferation, differentiation, apoptosis, necrosis, inflammation, angiogenesis, and fibrosis with double-edged effects depending on the type and stage of kidney injury. Here we will review the actions of TRAIL, OPG, and TWEAK on diabetic and non-diabetic kidney disease, in order to provide insights into their full clinical potential as biomarkers and/or therapeutic options against kidney disease.

Short-term exposure to ambient air pollution and circulating biomarkers of endothelial cell activation: The Framingham Heart Study

BACKGROUND

Short-term exposure to air pollution has been associated with cardiovascular events, potentially by promoting endothelial cell activation and inflammation. A few large-scale studies have examined the associations and have had mixed results.

METHODS

We included 3820 non-current smoking participants (mean age 56 years, 54% women) from the Framingham Offspring cohort examinations 7 (1998-2001) and 8 (2005-2008), and Third Generation cohort examination 1 (2002-2005), who lived within 50 km of a central monitoring station. We calculated the 1- to 7-day moving averages of fine particulate matter (PM_2.5), black carbon (BC), sulfate (SO₄^2-), nitrogen oxides (NO_x), and ozone before examination visits. We used linear mixed effect models for P-selectin, monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1, lipoprotein-associated phospholipase A2 activity and mass, and osteoprotegerin that were measured up to twice, and linear regression models for CD40 ligand and interleukin-18 that were measured once, adjusting for demographics, life style and clinical factors, socioeconomic position, time, and meteorology.

RESULTS

We found negative associations of PM_2.5 and BC with P-selectin, of ozone with MCP-1, and of SO₄^2- and NO_x with osteoprotegerin. At the 5-day moving average, a 5 µg/m³ higher PM_2.5 was associated with 1.6% (95% CI: - 2.8, - 0.3) lower levels of P-selectin; a 10 ppb higher ozone was associated with 1.7% (95% CI: - 3.2, - 0.1) lower levels of MCP-1; and a 20 ppb higher NO_x was associated with 2.0% (95% CI: - 3.6, - 0.4) lower levels of osteoprotegerin.

CONCLUSIONS

We did not find evidence of positive associations between short-term air pollution exposure and endothelial cell activation. On the contrary, short-term exposure to higher levels of ambient pollutants were associated with lower levels of P-selectin, MCP-1, and osteoprotegerin in the Framingham Heart Study.

Decrease in inflammatory biomarker concentration by intervention with selenium and coenzyme Q10: a subanalysis of osteopontin, osteoprotergerin, TNFr1, TNFr2 and TWEAK

Background

Inflammation is central to the pathogenesis of many diseases. Supplementation with selenium and coenzyme Q10 has been shown to reduce cardiovascular mortality, and increase cardiac function in elderly persons with a low intake of selenium. There are indications that one of the mechanisms of this positive effect is a decrease in inflammation.

Methods

Osteopontin, osteoprotegerin, sTNF receptor 1, sTNF receptor 2 and the tumor necrosis factor-like weak inducer of apoptosis called TWEAK, were determined in plasma after 6 months and 42 months in 219 community-living elderly persons, of whom 119 received supplements of selenium (200 μg/day) and coenzyme Q10 (200 mg/day), and 101 received a placebo. Repeated measures of variance were used to evaluate the levels, and the results were validated through ANCOVA analyses with adjustments for important covariates.

Results

Significantly lower concentrations of four of the five biomarkers for inflammation were observed as a result of the intervention with the supplements. Only TWEAK did not show significant differences.

Conclusion

In this sub-analysis of the intervention with selenium and coenzyme Q10 or placebo in an elderly community-living population, biomarkers for inflammation were evaluated. A significantly lower concentration in four of the five biomarkers tested could be demonstrated as a result of the supplementation, indicating a robust effect on the inflammatory system. The decrease in inflammation could be one of the mechanisms behind the positive clinical results on reduced cardiovascular morbidity and mortality reported earlier as a result of the intervention. The study is small and should be regarded as hypothesis-generating, but nonetheless adds important data about mechanisms presently known to increase the risk of clinical effects such as reduced cardiovascular mortality, increased cardiac function and better health-related quality of life scoring, as previously demonstrated in the active treatment group .

Trial registration

The intervention study was registered at Clinicaltrials.gov, and has the identifier NCT01443780 and registered on 09/30/2011.

Endogenous Calcification Inhibitors in the Prevention of Vascular Calcification: A Consensus Statement From the COST Action EuroSoftCalcNet

The physicochemical deposition of calcium-phosphate in the arterial wall is prevented by calcification inhibitors. Studies in cohorts of patients with rare genetic diseases have shed light on the consequences of loss-of-function mutations for different calcification inhibitors, and genetic targeting of these pathways in mice have generated a clearer picture on the mechanisms involved. For example, generalized arterial calcification of infancy (GACI) is caused by mutations in the enzyme ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (eNPP1), preventing the hydrolysis of ATP into pyrophosphate (PP_i). The importance of PP_i for inhibiting arterial calcification has been reinforced by the protective effects of PP_i in various mouse models displaying ectopic calcifications. Besides PP_i, Matrix Gla Protein (MGP) has been shown to be another potent calcification inhibitor as Keutel patients carrying a mutation in the encoding gene or Mgp-deficient mice develop spontaneous calcification of the arterial media. Whereas PP_i and MGP represent locally produced calcification inhibitors, also systemic factors contribute to protection against arterial calcification. One such example is Fetuin-A, which is mainly produced in the liver and which forms calciprotein particles (CPPs), inhibiting growth of calcium-phosphate crystals in the blood and thereby preventing their soft tissue deposition. Other calcification inhibitors with potential importance for arterial calcification include osteoprotegerin, osteopontin, and klotho. The aim of the present review is to outline the latest insights into how different calcification inhibitors prevent arterial calcification both under physiological conditions and in the case of disturbed calcium-phosphate balance, and to provide a consensus statement on their potential therapeutic role for arterial calcification.

Common mechanisms and holistic care in atherosclerosis and osteoporosis

Cardiovascular (CV) disease and osteoporosis (OP) have become increasing challenges in the aging population and even more in patients with inflammatory rheumatic diseases, such as rheumatoid arthritis, spondyloarthropathies, and systemic lupus erythematosus. In this review, we discuss how the epidemiology and pathogenesis of CV events and OP are overlapping. Smoking, diabetes mellitus, physical inactivity as conventional risk factors as well as systemic inflammation are among the modifiable risk factors for both CV events and bone loss. In rheumatic patients, systemic “high-grade” inflammation may be the primary driver of accelerated atherogenesis and bone resorption. In the general population, in which some individuals might have low-grade systemic inflammation, a holistic approach to drug treatment and lifestyle modifications may have beneficial effects on the bone as well as the vasculature. In rheumatic patients with accelerated inflammatory atherosclerosis and bone loss, the rapid and effective suppression of inflammation in a treat-to-target regime, aiming at clinical remission, is necessary to effectively control comorbidities.