Circulating Osteoprotegerin Levels and Long-Term Prognosis in Patients With Acute Coronary Syndromes

Effect of Denosumab or Alendronate on Vascular Calcification: Secondary Analysis of SALTIRE2 Randomized Controlled Trial

BACKGROUND

Patients with osteoporosis demonstrate increased vascular calcification but the effect of osteoporosis treatments on vascular calcification remains unclear. The present study aimed to examine whether coronary or aortic calcification are influenced by denosumab and alendronic acid treatment.

METHODS AND RESULTS

In a double-blind randomized controlled SALTIRE2 (Study Investigating the Effect of Drugs Used to Treat Osteoporosis on the Progression of Calcific Aortic Stenosis) trial, patients with aortic stenosis were randomized 2:1:2:1 to denosumab, placebo injection, alendronic acid, or placebo capsule. Participants underwent serial imaging with computed tomography and 18F-sodium fluoride positron emission tomography for the assessment of vascular calcium burden and calcification activity, respectively. We report the prespecified secondary analyses of 24-month change in coronary calcium score, and 12-month changes in thoracic aorta calcium score, coronary and aortic 18F-sodium fluoride activity. One hundred fifty patients with aortic stenosis (72±8 years; 21% female) were randomized to denosumab (n=49), alendronic acid (n=51), and placebo (injection n=25, capsule n=25). There were no differences in change in coronary calcium scores between placebo (16 [-64 to 148] Agatston units) and either denosumab (94 [0-212] Agatston units, P=0.24) or alendronic acid (34 [-62 to 134], P=0.99). There were no differences in change in thoracic aorta calcium scores between placebo (132 [22-512] Agatston units) and either denosumab (118 [11-340], P=0.75) or alendronic acid (116 [26-498] Agatston units, P=0.62). There were no differences in changes in coronary or aortic 18F-sodium fluoride activity between treatment groups.

CONCLUSIONS

Neither alendronic acid nor denosumab are associated with changes in the activity or progression of coronary or aortic calcification. Osteoporosis treatments do not appear to have major impact on vascular calcification of atherosclerosis.

REGISTRATION

https://www.clinicaltrials.gov; Unique identifier: NCT02132026.

Association of mineral and bone biomarkers with adverse cardiovascular outcomes and mortality in the German Chronic Kidney Disease (GCKD) cohort

Mineral and bone disorder (MBD) in chronic kidney disease (CKD) is tightly linked to cardiovascular disease (CVD). In this study, we aimed to compare the prognostic value of nine MBD biomarkers to determine those associated best with adverse cardiovascular (CV) outcomes and mortality. In 5 217 participants of the German CKD (GCKD) study enrolled with an estimated glomerular filtration rate (eGFR) between 30-60 mL·min-1 per 1.73 m2 or overt proteinuria, serum osteoprotegerin (OPG), C-terminal fibroblast growth factor-23 (FGF23), intact parathyroid hormone (iPTH), bone alkaline phosphatase (BAP), cross-linked C-telopeptide of type 1 collagen (CTX1), procollagen 1 intact N-terminal propeptide (P1NP), phosphate, calcium, and 25-OH vitamin D were measured at baseline. Participants with missing values among these parameters (n = 971) were excluded, leaving a total of 4 246 participants for analysis. During a median follow-up of 6.5 years, 387 non-CV deaths, 173 CV deaths, 645 nonfatal major adverse CV events (MACEs) and 368 hospitalizations for congestive heart failure (CHF) were observed. OPG and FGF23 were associated with all outcomes, with the highest hazard ratios (HRs) for OPG. In the final Cox regression model, adjusted for CV risk factors, including kidney function and all other investigated biomarkers, each standard deviation increase in OPG was associated with non-CV death (HR 1.76, 95% CI: 1.35-2.30), CV death (HR 2.18, 95% CI: 1.50-3.16), MACE (HR 1.38, 95% CI: 1.12-1.71) and hospitalization for CHF (HR 2.05, 95% CI: 1.56-2.69). Out of the nine biomarkers examined, stratification based on serum OPG best identified the CKD patients who were at the highest risk for any adverse CV outcome and mortality.

Prognostic role of osteoprotegerin and risk of coronary artery calcification: a systematic review and meta-analysis

Aim: Coronary artery calcification (CAC) is a predictor of atherosclerosis. However, the association of osteoprotegerin (OPG) with CAC is still controversial. Methods: Prospective cohort studies that provided odds ratios with 95% CIs were included from PubMed, Embase, Web of Science and Scopus through July 2022. Results: Out of 14 studies included in the systematic review, three studies with 7642 participants were included in the meta-analysis. The pooled odds ratio indicated a significant association between higher OPG levels and accelerated risk of CAC (1.15; 95% CI: 1.03-1.30; p < 0.001) with relatively no heterogeneity between studies (I² = 0%; p = 0.43). Conclusion: The results indicated that increased concentrations of OPG are positively associated with a 15% elevated odds of CAC after adjustment of major covariates.

Osteoprotegerin and Ischemic Stroke Prognosis: A Prospective Multicenter Study and Mendelian Randomization Analysis

BACKGROUND

Osteoprotegerin was implicated in vascular injury and inflammatory responses, but its prognostic value in ischemic stroke remained unclear. We aimed to prospectively investigate the association between plasma osteoprotegerin and ischemic stroke prognosis combined with a Mendelian randomization analysis.

METHODS

Our prospective study follows the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) reporting guideline. We measured baseline plasma osteoprotegerin levels for 3490 ischemic stroke patients recruited between August 2009 and May 2013 in 26 hospitals across China. The primary outcome was a composite outcome of death and major disability at 3 months after ischemic stroke.

RESULTS

After adjustment for age, sex, admission National Institutes of Health Stroke Scale score, and other important covariates, elevated osteoprotegerin levels were associated with increased risks of primary outcome (odds ratio, 1.40 [95% CI, 1.05-1.88]), death (hazard ratio, 2.05 [95% CI, 1.04-4.08]), and composite outcome of death and vascular events (hazard ratio, 2.00 [95% CI, 1.15-3.48]) when 2 extreme quartiles were compared. Each 1-SD higher log-osteoprotegerin was associated with a 18% (95% CI, 6%-32%) increased risk of primary outcome, 69% (95% CI, 31%-118%) increased risk of death, and 53% (95% CI, 24%-89%) increased risk of composite outcome of death and vascular events, respectively. Multiple-adjusted spline regression model showed a linear association of osteoprotegerin with primary outcome (P for linearity <0.001). Adding osteoprotegerin to conventional risk factors did not significantly improve discriminatory power (C statistics, 0.817 versus 0.818; P=0.232) but did slightly improve the risk reclassification of primary outcome (net reclassification improvement: 13.68%, P<0.001; integrated discrimination improvement: 0.23%, P=0.039). In Mendelian randomization analysis, genetically determined high plasma osteoprotegerin was associated with increased risk of primary outcome (odds ratio, 5.74 [95% CI, 1.12-29.44]; P=0.036).

CONCLUSIONS

Elevated plasma osteoprotegerin was associated with poor prognosis of ischemic stroke, and genetically determined high plasma osteoprotegerin was associated with an increased risk of primary outcome in Mendelian randomization analysis.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01840072.

Advances in congestive heart failure biomarkers

Congestive heart failure (CHF) is the leading cause of morbidity and mortality in the elderly worldwide. Although many biomarkers associated with in heart failure, these are generally prognostic and identify patients with moderate and severe disease. Unfortunately, the role of biomarkers in decision making for early and advanced heart failure remains largely unexplored. Previous studies suggest the natriuretic peptides have the potential to improve the diagnosis of heart failure, but they still have significant limitations related to cut-off values. Although some promising cardiac biomarkers have emerged, comprehensive data from large cohort studies is lacking. The utility of multiple biomarkers that reflect various pathophysiologic pathways are increasingly being explored in heart failure risk stratification and to diagnose disease conditions promptly and accurately. MicroRNAs serve as mediators and/or regulators of renin-angiotensin-induced cardiac remodeling by directly targeting enzymes, receptors and signaling molecules. The role of miRNA in HF diagnosis is a promising area of research and further exploration may offer both diagnostic and prognostic applications and phenotype-specific targets. In this review, we provide insight into the classification of different biochemical and molecular markers associated with CHF, examine clinical usefulness in CHF and highlight the most clinically relevant.

Estrogen Receptor Subtypes Elicit a Distinct Gene Expression Profile of Endothelial-Derived Factors Implicated in Atherosclerotic Plaque Vulnerability

In the presence of established atherosclerosis, estrogens are potentially harmful. MMP-2 and MMP-9, their inhibitors (TIMP-2 and TIMP-1), RANK, RANKL, OPG, MCP-1, lysyl oxidase (LOX), PDGF-β, and ADAMTS-4 play critical roles in plaque instability/rupture. We aimed to investigate (i) the effect of estradiol on the expression of the abovementioned molecules in endothelial cells, (ii) which type(s) of estrogen receptors mediate these effects, and (iii) the role of p21 in the estrogen-mediated regulation of the aforementioned factors. Human aortic endothelial cells (HAECs) were cultured with estradiol in the presence or absence of TNF-α. The expression of the aforementioned molecules was assessed by qRT-PCR and ELISA. Zymography was also performed. The experiments were repeated in either ERα- or ERβ-transfected HAECs and after silencing p21. HAECs expressed only the GPR-30 estrogen receptor. Estradiol, at low concentrations, decreased MMP-2 activity by 15-fold, increased LOX expression by 2-fold via GPR-30, and reduced MCP-1 expression by 3.5-fold via ERβ. The overexpression of ERα increased MCP-1 mRNA expression by 2.5-fold. In a low-grade inflammation state, lower concentrations of estradiol induced the mRNA expression of MCP-1 (3.4-fold) and MMP-9 (7.5-fold) and increased the activity of MMP-2 (1.7-fold) via GPR-30. Moreover, p21 silencing resulted in equivocal effects on the expression of the abovementioned molecules. Estradiol induced different effects regarding atherogenic plaque instability through different ERs. The balance of the expression of the various ER subtypes may play an important role in the paradoxical characterization of estrogens as both beneficial and harmful.

Cathepsin S Levels and Survival Among Patients With Non-ST-Segment Elevation Acute Coronary Syndromes

BACKGROUND

Patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) are at high residual risk for long-term cardiovascular (CV) mortality. Cathepsin S (CTSS) is a lysosomal cysteine protease with elastolytic and collagenolytic activity that has been involved in atherosclerotic plaque rupture.

OBJECTIVES

The purpose of this study was to determine the following: 1) the prognostic value of circulating CTSS measured at patient admission for long-term mortality in NSTE-ACS; and 2) its additive value over the GRACE (Global Registry of Acute Coronary Events) risk score.

METHODS

This was a single-center cohort study, consecutively recruiting patients with adjudicated NSTE-ACS (n = 1,112) from the emergency department of an academic hospital. CTSS was measured in serum using enzyme-linked immunosorbent assay. All-cause mortality at 8 years was the primary endpoint. CV death was the secondary endpoint.

RESULTS

In total, 367 (33.0%) deaths were recorded. CTSS was associated with increased risk of all-cause mortality (HR for highest vs lowest quarter of CTSS: 1.89; 95% CI: 1.34-2.66; P < 0.001) and CV death (HR: 2.58; 95% CI: 1.15-5.77; P = 0.021) after adjusting for traditional CV risk factors, high-sensitivity C-reactive protein, left ventricular ejection fraction, high-sensitivity troponin-T, revascularization and index diagnosis (unstable angina/ non-ST-segment elevation myocardial infarction). When CTSS was added to the GRACE score, it conferred significant discrimination and reclassification value for all-cause mortality (Delta Harrell's C: 0.03; 95% CI: 0.012-0.047; P = 0.001; and net reclassification improvement = 0.202; P = 0.003) and CV death (AUC: 0.056; 95% CI: 0.017-0.095; P = 0.005; and net reclassification improvement = 0.390; P = 0.001) even after additionally considering high-sensitivity troponin-T and left ventricular ejection fraction.

CONCLUSIONS

Circulating CTSS is a predictor of long-term mortality and improves risk stratification of patients with NSTE-ACS over the GRACE score.

Association of Serum Osteoprotegerin Level With Myocardial Injury and Cardiovascular Calcification in Chronic Kidney Disease Patients

Background

Chronic kidney disease has emerged as a significant independent risk factor for cardiovascular disease. Cardiovascular calcification is an active process involving a complex interaction of inducers and inhibitors. High sensitivity cardiac troponin T assay detects troponin T with higher sensitivity and precision at an earlier point of time than the conventional assays, and is associated with poor outcomes. Serum osteoprotegerin is classed as an inhibitory factor for cardiovascular calcification. It is involved in the pathological processes of vascular damage and linked to the excess cardiovascular morbidity. The aim of the present study was to evaluate the extent of cardiovascular calcification and serum high sensitivity cardiac troponin T level, and their association with serum osteoprotegerin level in patients with chronic kidney disease stages 3-5.

Methods

90 chronic kidney disease patients were enrolled in this study, and they were divided into two groups: group (1) included 45 non-dialysis-dependent chronic kidney disease patients (stages 3-5) and group (2) included 45 chronic hemodialysis patients. Each group further subdivided according to the presence of cardiovascular calcification into subgroup A and B. Vascular calcifications were assessed by lateral lumbar, pelvis and hands X-ray radiographs. Valvular calcification was assessed by echocardiography. Serum cardiac troponin T was measured by high sensitivity assay and serum osteoprotegerin was measured by ELISA.

Results

Cardiovascular calcification distribution was 22.2% in group (1) and 33.3% in group (2). Serum osteoprotegerin and troponin T in calcification groups (1A and 2A) were significantly higher than non-calcification groups (1B and 2B; P < 0.001). Osteoprotegerin correlated positively with high sensitivity cardiac troponin T (rs = 0.72, P < 0.001). cardiovascular calcification correlated positively with osteoprotegerin, troponin T, and phosphorus. osteoprotegerin and phosphorus were significant independent predictors of cardiovascular calcification at cut-off values ≥4.6 ng/L and ≥6.95 mg/dl, respectively (P < 0.001). Serum phosphorus and creatinine were independent predictors of osteoprotegerin (P < 0.001 and 0.048, respectively).

Conclusion

Osteoprotegerin is strongly associated with cardiovascular calcification and high sensitivity cardiac troponin T. In addition, there is a positive association between calcification and troponin T. This suggests a role for osteoprotegerin in the pathogenesis and risk stratification of cardiovascular calcification and myocardial injury in chronic kidney disease patients with a potential role as a therapeutic target.

Association of serum sclerostin and osteoprotegerin levels with the presence, severity and prognosis in patients with acute myocardial infarction

Background

Bone-related proteins (such as sclerostin and osteoprotegerin [OPG]) are involved in the development of atherosclerosis. However, the relationship between bone-related proteins and acute myocardial infarction (AMI) has not been extensively evaluated. The purpose of this study was to assess the association of serum sclerostin and OPG with the presence, severity and prognosis in patients with AMI.

Methods

This study prospectively enrolled 152 patients attacked by acute chest pain. Serum sclerostin and OPG were detected within the first 24 h after AMI diagnosis by ELISA kits. The AMI predictive efficacy of sclerostin and OPG were analyzed by receiver operating characteristics (ROC) curve. Univariable and multivariable linear regression analyses were performed to determine the association between bone-related proteins and scores indicating the severity of coronary artery occlusion. Moreover, prognostic values were assessed by Kaplan–Meier curves and Cox regression analysis.

Results

There were 92 patients in AMI group, 60 in non-AMI group. Serum levels of sclerostin and OPG were significantly higher in AMI group than in non-AMI group (all p < 0.001), which showed predictive value for the presence of AMI (all p < 0.001). The area under the ROC curve values of sclerostin and OPG were 0.744 and 0.897, respectively. A multivariable linear regression analysis demonstrated that Ln-transformed sclerostin (β = 0.288, p = 0.009) and Ln-transformed OPG (Ln-OPG: β = 0.295, p = 0.019) levels were associated with GENISINI score, independently of conventional clinical parameters. In addition, Ln-OPG levels were still positively associated with GRACE score after adjustments (β = 0.320, p = 0.001). During a 1-year follow-up, patients above the median of sclerostin levels had higher incidence of major adverse cardiac events (MACE) than those below the median (p = 0.028). It was also observed that the MACE rates were higher in patients above the median of OPG levels, though no statistic importance (p = 0.060). After adjusting conventional risk factors by multivariate Cox regression, Ln-OPG was associated with incident MACE (hazard ratio = 2.188 [95% confidence intervals 1.102–4.344], p = 0.025).

Conclusions

Bone-related proteins could exert a potential role in early risk stratification and prognosis assessment in patients with AMI.

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 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.

Plasma osteoprotegerin levels are associated with the presence and burden of cerebral small vessel disease in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Osteoprotegerin (OPG) is a component of the tumor necrosis factor receptor superfamily. Several studies have shown a relationship between OPG and cardiovascular diseases. We hypothesized that there is a relationship between plasma OPG levels and cerebral small vessel disease (SVD).

METHODS

Patients diagnosed with their first cerebral ischemic infarction between April 2014 and March 2017 were enrolled. All the enrolled patients were evaluated through the hospital stroke protocol, including routine blood tests, brain imaging, and measuring the plasma OPG levels. The presence and burden of cerebral SVD [cerebral microbleeds (CMBs), asymptomatic lacunar infarction (ALI), high-grade perivascular space (HPVS), high-grade white matter hyperintensity (HWMH)], and total SVD score were assessed through brain magnetic resonance imaging.

RESULTS

Of the 270 patients included in our study, 158 (58.5%) were men. The mean age of the patients was 63.8 ± 11.6 years. In multivariable analysis, plasma OPG levels were positively associated with the presence and burden of each cerebral SVD. The odds ratios (OR) of CMBs, ALI, HPVS, and HWMH for the association of OPG per standard deviation (SD) increase were 1.58 [95% confidence interval (CI), 1.09-2.27], 1.40 (95% CI, 1.04-1.88), 1.88 (95% CI, 1.27-2.78), and 1.47 (95% CI, 1.04-2.08), respectively. Plasma OPG levels were positively correlated with total SVD score (beta = 0.211, standard error = 0.061, p-value = 0.009, R² = 0.275).

CONCLUSIONS

Plasma OPG levels correlate with the presence and burden of cerebral SVD in patients with acute ischemic stroke.

Plasma proteins associated with cardiovascular death in patients with chronic coronary heart disease: A retrospective study

BACKGROUND

Circulating biomarkers are associated with the development of coronary heart disease (CHD) and its complications by reflecting pathophysiological pathways and/or organ dysfunction. We explored the associations between 157 cardiovascular (CV) and inflammatory biomarkers and CV death using proximity extension assays (PEA) in patients with chronic CHD.

METHODS AND FINDINGS

The derivation cohort consisted of 605 cases with CV death and 2,788 randomly selected non-cases during 3-5 years follow-up included in the STabilization of Atherosclerotic plaque By Initiation of darapLadIb TherapY (STABILITY) trial between 2008 and 2010. The replication cohort consisted of 245 cases and 1,042 non-cases during 12 years follow-up included in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study between 1997 and 2000. Biomarker levels were measured with conventional immunoassays and/or with the OLINK PEA panels CVD I and Inflammation. Associations with CV death were evaluated by Random Survival Forest (RF) and Cox regression analyses. Both cohorts had the same median age (65 years) and 20% smokers, while there were slight differences in male sex (82% and 76%), hypertension (70% and 78%), and diabetes (39% and 30%) in the respective STABILITY and LURIC cohorts. The analyses identified 18 biomarkers with confirmed independent association with CV death by Boruta analyses and statistical significance (all p < 0.0001) by Cox regression when adjusted for clinical characteristics in both cohorts. Most prognostic information was carried by N-terminal prohormone of brain natriuretic peptide (NTproBNP), hazard ratio (HR for 1 standard deviation [SD] increase of the log scale of the distribution of the biomarker in the replication cohort) 2.079 (95% confidence interval [CI] 1.799-2.402), and high-sensitivity troponin T (cTnT-hs) HR 1.715 (95% CI 1.491-1.973). The other proteins with independent associations were growth differentiation factor 15 (GDF-15) HR 1.728 (95% CI 1.527-1.955), transmembrane immunoglobulin and mucin domain protein (TIM-1) HR 1.555 (95% CI 1.362-1.775), renin HR 1.501 (95% CI 1.305-1.727), osteoprotegerin (OPG) HR 1.488 (95% CI 1.297-1.708), soluble suppression of tumorigenesis 2 protein (sST2) HR 1.478 (95% CI 1.307-1.672), cystatin-C (Cys-C) HR 1.370 (95% CI 1.243-1.510), tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) HR 1.205 (95% CI 1.131-1.285), carbohydrate antigen 125 (CA-125) HR 1.347 (95% CI 1.226-1.479), brain natriuretic peptide (BNP) HR 1.399 (95% CI 1.255-1.561), interleukin 6 (IL-6) HR 1.478 (95% CI 1.316-1.659), hepatocyte growth factor (HGF) HR 1.259 (95% CI 1.134-1.396), spondin-1 HR 1.295 (95% CI 1.156-1.450), fibroblast growth factor 23 (FGF-23) HR 1.349 (95% CI 1.237-1.472), chitinase-3 like protein 1 (CHI3L1) HR 1.284 (95% CI 1.129-1.461), tumor necrosis factor receptor 1 (TNF-R1) HR 1.486 (95% CI 1.307-1.689), and adrenomedullin (AM) HR 1.750 (95% CI 1.490-2.056). The study is limited by the differences in design, size, and length of follow-up of the 2 studies and the lack of results from coronary angiograms and follow-up of nonfatal events.

CONCLUSIONS

Profiles of levels of multiple plasma proteins might be useful for the identification of different pathophysiological pathways associated with an increased risk of CV death in patients with chronic CHD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00799903.

Estrogen inhibits vascular calcification in rats via hypoxia-induced factor-1α signaling

OBJECTIVE

Calcification serves as a surrogate for atherosclerosis-associated vascular diseases, and coronary artery calcification is mediated by multiple pathogenic factors. Estrogen is a known factor that protects the arterial wall against atherosclerosis, but its role in the coronary artery calcification development remains largely unclear. This study tested the hypothesis that estrogen inhibits coronary artery calcification via the hypoxia-induced factor-1α pathway.

METHODS

Eight-week-old healthy female Sprague-Dawley rats were castrated, and vitamin D3 was administered orally to establish. Hypoxia-induced factor-1 inhibitor was administered to test its effect on vascular calcification and expression of bone morphogenetic protein 2 and runt-related transcription factor-2. Vascular smooth muscle cell calcification was induced with CaCl2 in rat aortic smooth muscle cells in the presence or absence of E2(17β-estradiol) and bone morphogenetic protein 2 siRNA intervention.

RESULTS

The estrogen levels in ovariectomized rats were significantly decreased, as determined by ELISA. Expression of hypoxia-induced factor-1α mRNA and protein was significantly increased in vascular cells with calcification as compared to those without calcification (p < 0.01). E2 treatment decreased the calcium concentration in vascular cell calcification and cell calcium nodules in vitro (p < 0.05). E2 also lowered the levels of hypoxia-induced factor-1α mRNA and protein (p < 0.01). Oral administration of the hypoxia-induced factor-1α inhibitor dimethyloxetane in castrated rats alleviated vascular calcification and expression of osteogenesis-related transcription factors, bone morphogenetic protein 2 and RUNX2 (p < 0.01). Finally, bone morphogenetic protein 2 siRNA treatment decreased the levels of p-Smad1/5/8 in A7r5 calcification cells (p < 0.01).

CONCLUSION

Estrogen deficiency enhances vascular calcification. Treatment with estrogen reduces the expression of hypoxia-induced factor-1α as well as vascular calcification in rats. The estrogen effects occur in a fashion dependent on hypoxia-induced factor-1α regulation of bone morphogenetic protein-2 and downstream Smad1/5/8.

Sex Differences in Proatherogenic Cytokine Levels

BACKGROUND

It has been shown that sex affects immunity, including cytokine production. Given that atherosclerosis is an inflammatory disease promoted by specific cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, we aimed at evaluating whether sex could affect the levels of these proatherogenic cytokines in a group of healthy adults. In this analysis, we also included other cytokines and peptides that have been implicated in atherosclerosis development and progression.

METHODS

A total of 104 healthy adults were recruited; we measured circulating levels of IL-1β, IL-6, TNF-α, angiotensins and angiotensin-converting enzyme-2 (ACE2), as well as osteoprotegerin and receptor activator of nuclear factor κB ligand (RANKL).

RESULTS

IL-1β, IL-6, and TNF-α were significantly higher in men as compared to women. They were all associated with testosterone and the testosterone/estradiol ratio. They remained significantly associated with sex (but not with hormones) after being tested for potential confounders.

CONCLUSIONS

Sex seems to influence the levels of proatherogenic cytokines. This is consistent not only with sex differences in vulnerability to infections but also with the higher cardiovascular risk exhibited by the male gender as compared to the female gender. Nevertheless, this association is only partly explained by hormone levels.

Osteoprotegerin promotes intimal hyperplasia and contributes to in-stent restenosis: Role of an αVβ3/FAK dependent YAP pathway

OBJECTIVE

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are related to in-stent-restenosis (ISR) following percutaneous coronary intervention (PCI). Osteoprotegerin (OPG) has been implicated in various vascular diseases. However, the effects of OPG on ISR and the underlying mechanism remained elusive. We here investigated the association between OPG and ISR, and to demonstrate the role and potential mechanisms of OPG in neointimal hyperplasia.

APPROACH AND RESULTS

From 2962 patients who received coronary angiography and follow-up coronary angiography at approximately one year, 291 patients were diagnosed with ISR, and another 291 gender- and age- matched patients without ISR were selected as controls. Serum OPG levels were significantly increased in patients with ISR. Multivariable logistic regression analysis indicated that OPG level was independently associated with the increased risk of ISR. In a mouse femoral artery wire injury model, upregulated OPG was evidenced in vascular tissue after injury. OPG deletion attenuated the vascular injury-induced neointimal hyperplasia and related gene expression in mice. OPG promoted neointimal hyperplasia and human aortic smooth muscle cell (hASMC) proliferation and migration through activation of yes-associated protein (YAP), a major downstream effector of the Hippo signaling pathway, whereas knockdown or inhibition of YAP in hASMCs blunted OPG-induced above effects. Moreover, we found that OPG, as a ligand for integrin αVβ3, mediated phosphorylation of focal adhesion kinase (FAK) and actin cytoskeleton reorganization, resulting in YAP dephosphorylation in hASMCs. OPG-dependent YAP and VSMC activation was prevented by treatment with αVβ3-blocking antibodies and inhibitors of FAK and actin stress fibers.

CONCLUSIONS

Increased serum OPG levels are associated with increased risk of ISR following PCI and OPG could promote neointimal hyperplasia in response to injury through integrin αVβ3 mediated FAK and YAP activation, indicating OPG/YAP inhibition might serve as an attractive novel target for the prevention of ISR after PCI.

Preoperative biomarker evaluation for the prediction of cardiovascular events after major vascular surgery

OBJECTIVE

The cause of perioperative myocardial infarction (PMI) is postulated to involve hemodynamic stress or coronary plaque destabilization. We aimed to evaluate perioperative factors in patients with peripheral artery disease (PAD) undergoing major vascular surgery to determine the likely mechanisms and predictors of PMI.

METHODS

This was a prospective cohort study of 133 patients undergoing major vascular surgery including open abdominal aortic aneurysm (AAA) repair (n = 40) and major suprainguinal or infrainguinal arterial bypasses (non-AAA; n = 93). Preoperative assessment with history, physical examination, and peripheral artery tonometry was performed in addition to plasma sampling of biomarkers associated with inflammation and coronary plaque instability. The primary outcome was occurrence of a 30-day cardiovascular event (CVE; composite of PMI [troponin I elevation >99th percentile reference of ≥0.1 μg/L], stroke, or death).

RESULTS

Of 133 patients, 36 patients (27%) developed a 30-day CVE after vascular surgery, and all were PMI. Patients with 30-day CVE were older (75 ± 8 years vs 69 ± 10 years, mean ± standard deviation; P = .001), had higher prevalence of hypertension (94% vs 79%; P = .01) and preoperative beta-blocker therapy (50% vs 29%; P = .02), and had longer duration of surgery (5.1 ± 1.8 hours vs 4.0 ± 1.1 hours; P < .0001). Significant elevations in cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), troponin I, high-sensitivity troponin T, matrix metalloproteinase 3, and osteoprotegerin occurred in those who developed 30-day CVE (all P < .05). Multivariate binary logistic regression identified AAA surgery and log-transformed NT-proBNP to be independent preoperative predictors of 30-day CVE (area under the receiver operating characteristic curve = 0.81).

CONCLUSIONS

In patients with peripheral artery disease undergoing major vascular surgery, the likely mechanism of PMI appears to be the hemodynamic stress related to the type and duration of surgery. NT-proBNP was a useful independent predictor of CVE and thus may serve as an important biomarker of cardiovascular fitness for surgery.

Regulatory Effects and Interactions of the Wnt and OPG-RANKL-RANK Signaling at the Bone-Cartilage Interface in Osteoarthritis

Cartilage and the bordering subchondral bone form a functionally active regulatory interface with a prominent role in osteoarthritis pathways. The Wnt and the OPG-RANKL-RANK signaling systems, as key mediators, interact in subchondral bone remodeling. Osteoarthritic osteoblasts polarize into two distinct phenotypes: a low secretory and an activated, pro-inflammatory and anti-resorptive subclass producing high quantities of IL-6, PGE2, and osteoprotegerin, but low levels of RANKL, thus acting as putative effectors of subchondral bone sclerosis. Wnt agonists, Wnt5a, Wisp-1 initiate excessive bone remodeling, while Wnt3a and 5a simultaneously cause loss of proteoglycans and phenotype shift in chondrocytes, with decreased expression of COL2A, aggrecan, and Sox-9. Sclerostin, a Wnt antagonist possesses a protective effect for the cartilage, while DKK-1 inhibits VEGF, suspending neoangiogenesis in the subchondral bone. Experimental conditions mimicking abnormal mechanical load, the pro-inflammatory milieu, but also a decreased OPG/RANKL ratio in the cartilage, trigger chondrocyte apoptosis and loss of the matrix via degradative matrix metalloproteinases, like MMP-13 or MMP-9. Hypoxia, an important cofactor exerts a dual role, promoting matrix synthesis via HIF-1α, a Wnt silencer, but turning on HIF-2α that enhances VEGF and MMP-13, along with aberrant collagen expression and extracellular matrix deterioration in the presence of pro-inflammatory cytokines.

Osteoprotegerin as a biomarker of geriatric frailty syndrome

The lack of a univocal definition of frailty, a condition frequently found in the elderly population which is correlated with an increased risk of mortality, has prompted the search for clinical and laboratory parameters associated with this condition. Whereas OPG is a protein involved in different pathophysiological conditions including bone, vascular, immune and tumor disease and studies found a positive linear correlation between OPG and age we hypothesized that it may represent a frailty marker in the elderly.We conducted an observational study of 172 elderly subjects, with and without hip fracture, including a multidimensional geriatric evaluation and a laboratory evaluation, aimed to evaluate the association between OPG and frailty.Frailty Score was associated with FT3 and osteoprotegerin (OPG), regardless of fracture event. Excluding subjects with hip fracture, in whom the acute event had a direct effect on bone production of OPG, the Frailty Score showed a linear correlation with circulating levels of osteoprotegerin.In the elderly, an increase in osteoprotegerin levels may reflect a progressive accumulation of organ damage leading to the development of frailty. The correlation between OPG and Frailty Score found in our study points to its potential use as a biomarker for geriatric frailty syndrome.

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.

Association of OPG-RANKL ratio with left ventricular hypertrophy and geometric remodeling in male overweight/obese youths

PURPOSE

Receptor activator of nuclear factor kappa B ligand/receptor activator of nuclear factor kappa B/osteoprotegerin (RANKL/RANK/OPG) axis has been hypothesized as a potential mediator of left ventricular hypertrophy (LVH). The aim of the study was to assess whether circulating concentrations of RANKL, RANK, and OPG were associated with early signs of morphological cardiac changes in overweight/obese youths.

METHODS

We determined serum levels of RANKL, RANK and OPG by enzyme-linked immunosorbent assays in 188 overweight/obese children and adolescents. LV mass index (LVMI) and relative wall thickness (RWT) were estimated using M-mode echocardiography.

RESULTS

OPG and RANKL levels were higher among girls than among boys [1.73 (1.64-1.86) and 3.28 (1.90-6.37) pmol/L, respectively, vs. 1.69 (1.59-1.82) and 2.12 (1.52-3.80) pmol/L; p = 0.02 and p = 0.0001, respectively], but the OPG/RANKL ratio was lower [0.52 (0.26-0.88) vs 0.77 (0.44-1.11); p = 0.001]. In gender-specific multivariate linear regression, OPG/RANKL ratio was associated with LVMI and RWT in boys but not in girls. In multiple logistic regression, after adjustment for clinical variables, OPG/RANKL ratio was associated with concentric remodeling, eccentric and concentric LVH in boys but not in girls.

CONCLUSION

OPG/RANKL ratio is independently associated with LVH and patterns of LV structural remodeling in male overweight/obese children and adolescents.

The Emerging Role of Bone Markers in Diagnosis and Risk Stratification of Patients With Coronary Artery Disease

Molecules that govern bone metabolism, such as osteoprotegerin (OPG) and osteopontin (OPN), have been isolated from other tissues, including blood vessels. Atherosclerosis and coronary artery disease (CAD) are leading causes of mortality worldwide. Despite novel biochemical and imaging techniques, early detection of CAD is still unsatisfactory. Experimental data indicate that bone turnover markers (BTMs) contribute to the development of atherosclerosis. This finding has sparked interest in their clinical use. This narrative review analyzed information from >50 human studies, which strongly suggest that OPG, OPN, and alkaline phosphatase (ALP) serum concentrations are altered in patients with CAD. Osteoprotegerin seems to be more useful for the detection of early disease, while OPN and ALP are recruited in vessels after the establishment of disease. Osteocalcin may be used as a flow cytometry marker for endothelial progenitor cells and can constitute a marker to monitor response to interventional treatments and risk of restenosis. However, most data derive from observational studies. Incorporation of BTMs in multifactorial computational algorithms could further determine their role in CAD diagnosis and prognosis together with other imaging techniques and biochemical markers.

Osteoprotegerin and Cardiovascular Events in High-Risk Populations: Meta-Analysis of 19 Prospective Studies Involving 27 450 Participants

Background Osteoprotegerin is a cytokine involved in bone metabolism as well as vascular calcification and atherogenesis. Although circulating osteoprotegerin levels are robustly associated with incident cardiovascular disease ( CVD ) in the general population, its relevance as a biomarker among populations at high CVD risk is less clear. Methods and Results Three independent reviewers systematically searched PubMed, EMBASE , and Web of Science to identify prospective studies that had recruited participants on the basis of having conditions related to high CVD risk. A total of 19 studies were eligible for inclusion, reporting on 27 450 patients with diabetes mellitus (2 studies), kidney disease (7 studies), preexisting heart disease (5 studies), or recent acute coronary syndromes (5 studies) at baseline. Over a mean follow-up of 4.2 years, 4066 CVD events were recorded. In a random-effects meta-analysis, the pooled risk ratio for CVD events comparing people in the top versus the bottom tertile of osteoprotegerin concentration was 1.30 (95% confidence interval, 1.12-1.50; P<0.001; I2=68.3%). There was evidence for presence of publication bias ( P value from Egger's test=0.013). Correction for publication bias using the trim-and-fill method reduced the risk ratio to 1.21 (95% confidence interval, 1.03-1.42; P<0.001). The risk ratios did not vary significantly by population type, geographical region, statistical adjustment, sample or assay type, age, sex, or length of follow-up. Conclusions In populations at high CVD risk, elevated circulating osteoprotegerin levels are associated with a higher risk for future CVD events. The magnitude of association appears weaker than in the general population.

Elevated serum osteoprotegerin is associated with increased left ventricular mass index and myocardial stiffness

AIM

Osteoprotegerin (OPG) is associated with a poor prognosis in patients with heart failure with preserved ejection fraction (HFpEF). OPG has also been associated with fibrosis and collagen cross-linking, which increase arterial and left ventricle (LV) myocardial stiffness. Little is known about the relation of OPG and LV structure and function in African-Americans who are disproportionately affected by HFpEF.

METHODS AND RESULTS

Our analysis included 1172 participants with preserved LV ejection fraction (>50%) from the African-American cohort in the Genetic Epidemiology Network of Arteriopathy Study (mean age 63 years, 72% female). We used diastolic wall strain indicator measured by echocardiography to assess LV myocardial stiffness. Diastolic wall strain was calculated as (LV posterior thickness at end-systole - LV posterior thickness at end-diastole)/LV posterior thickness at end-systole. Associations between OPG levels and indices of arterial and LV structure and function were evaluated by using generalized linear mixed models and adjusted for possible confounders. OPG levels were correlated with age, female sex, presence of hypertension and diabetes, and lower estimated glomerular filtration rate (P < 0.05 for all). Multivariable analysis revealed that higher OPG levels were associated with greater LV mass index, increased LV myocardial stiffness, and higher N-terminal prohormone brain natriuretic peptide levels (P < 0.05 for all).

CONCLUSION

In African-Americans, higher OPG levels were associated with characteristics common in patients with HFpEF and were significantly associated with known precursors to HFpEF. These findings indicate a potential role for OPG in the pathophysiology of HFpEF in African-Americans.

Elevated Circulating Osteoprotegerin Levels in the Plasma of Hemodialyzed Patients With Severe Artery Calcification

We studied the correlations between circulating osteoprotegerin (OPG) level and radial artery calcification (RAC) assessed histologically and carotid artery intima-media thickness (CCA-IMT). Moreover, we studied the relationship between OPG levels and all-cause and cardiovascular (CV) mortality during a 5-year observation period. The study comprised 59 CKD patients (36 hemodialyzed (HD), 23 predialysis). The biochemical parameters included: creatinine, calcium, phosphate, intact parathormone, C-reactive protein, interleukin-6, tumor necrosis factor receptor II (TNFRII), transforming growth factor-β, hepatocyte growth factor, fibroblast growth factor 23, osteonectin (ON), osteopontin, osteoprotegerin, and osteocalcin. CCA-IMT and the presence of atherosclerotic plaques was assessed by ultrasound. Fragments of radial artery obtained during creation of HD access were prepared for microscopy and stained for calcifications with alizarin red. RAC was detected in 34 patients (58%). In multiple regression adjusted for dialysis status, TNFRII, ON and Framingham risk score (FRS) were identified as the independent predictors of OPG. Serum OPG above the median value of 7.55 pmol/L significantly predicted the presence of RAC in simple logistic regression (OR 5.33; 95%CI 1.39-20.4; P = 0.012) and in multiple logistic regression adjusted for FRS, dialysis status and CCA-IMT values (OR 6.56; 95%CI 1.06-40.6; P = 0.036). OPG levels above the median were associated with higher CCA-IMT values (1.02 ± 0.10 vs. 0.86 ± 0.13; P < 0.001) and predicted the presence of atherosclerotic plaques in carotid artery (OR 14.4; 95%CI 2.84-72.9; P < 0.001), independently of FRS, dialysis status and RAC. In this study, elevated serum OPG levels correlated with higher CCA-IMT, the presence of atherosclerotic plaques and the severity of the RAC independently of each other. During follow-up, 25 patients (42%) died, including 21 due to CV causes. In multiple Cox regression, OPG above the median predicted overall survival independently of dialysis status, Framingham risk score, CCA-IMT above the median value, and the presence of atherosclerotic plaques in CCA, but not independently of RAC. We postulate that circulating OPG may play a dual role as a marker for both medial arterial calcification and atherosclerosis, hence it seems to be a valuable tool for assessing CV risk in patients with CKD. OPG might be an early indicator of all-cause mortality in CKD patients with advanced medial arterial calcification.

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.

The Role of Osteoprotegerin as a Cardioprotective Versus Reactive Inflammatory Marker: the Chicken or the Egg Paradox

Cardiovascular disease is one of the most frequent causes of mortality and morbidity worldwide. Several variables have been identified as risk factors for cardiovascular disease. Recently, the role of receptor activator of nuclear factor kappa B, receptor activator of nuclear factor kappa B ligand, and the osteoprotegerin system has been recognized as more important in the pathogenesis of cardiovascular disease. Besides their roles in the regulation of bone resorption, these molecules have been reported to be associated with the pathophysiology of cardiovascular disease. There are conflicting data regarding the impact of osteoprotegerin, a glycoprotein with a regulatory role in the cardiovascular system. The aim of this review is to discuss the current knowledge and the role of osteoprotegerin in cardiovascular disease.

Prognostic significance of arterial stiffness and osteoprotegerin in patients with stable coronary artery disease

BACKGROUND

Arterial stiffness and vascular calcification significantly contribute to coronary atherosclerosis progression. The prognostic value of increased arterial stiffness and vascular calcification in subjects with stable coronary artery disease (CAD) after percutaneous coronary intervention(PCI) is currently under question.

MATERIALS AND METHODS

We randomly enrolled 262 patients with stable CAD 1 month after successful PCI. Carotid-femoral pulse wave velocity (PWV) was measured as a well-established index of central aortic stiffness. Osteoprotegerin (OPG) plasma levels were measured as a biomarker of vascular calcification. Patients were followed up prospectively up to 52 months. The primary endpoint was the composite of death from cardiovascular causes, myocardial infarction, stroke or hospitalization for cardiovascular causes.

RESULTS

During the follow-up period, 48 patients presented the primary composite endpoint. Subjects who presented the primary endpoint, compared to subjects free of cardiovascular events, had significantly increased PWV (9.45 ± 2.19 m/s vs 8.73 ± 2.07 m/s, P = .04) and OPG levels (4.21 ± 2.19 pmol/L vs 3.18 ± 1.74 pmol/L, P = .003). Survival analysis indicated that PWV predicted adverse cardiac events MACE (Hazard ratio = 1.29 95%CI: 1.07-1.57, P = .008) independently from confounders such as age, sex, smoking habits, ejection fraction, extent of coronary artery disease, hypertension and diabetes mellitus. Interestingly, for every increase in pulse wave velocity by 1 m/s, there is an anticipated increase in the risk of major adverse cardiovascular event (MACE) by 29%.

CONCLUSIONS

These findings extend the current knowledge concerning the role of arterial stiffness as powerful biomarkers in cardiovascular disease. Measurement of PWV might have a role in ascertaining prognosis and managing treatment in patients with stable CAD after PCI.

Osteoprotegerin rich tumor microenvironment: implications in breast cancer

Osteoprotegerin (OPG) is a soluble decoy receptor for tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL). It belongs to the tumor necrosis factor receptor superfamily (TNFRSF). OPG was initially discovered to contribute to homeostasis of bone turnover due to its capability of binding to receptor activator of nuclear factor-kappaB (NF-kB). However, apart from bone turnover, OPG plays important and diverse role(s) in many biological functions. Besides having anti-osteoclastic activity, OPG is thought to exert a protective anti-apoptotic action in OPG-expressing tumors by overcoming the physiologic mechanism of tumor surveillance exerted by TRAIL. Along with inhibiting TRAIL induced apoptosis, it can induce proliferation by binding to various cell surface receptors and thus turning on the canonical cell survival and proliferative pathways. OPG also induces angiogenesis, one of the hallmarks of cancer, thus facilitating tumor growth. Recently, the understanding of OPG and its different roles has been augmented substantially. This review is aimed at providing a very informative overview as to how OPG affects cancer progression especially breast cancer.

Osteoprotegerin Is Associated With Major Bleeding But Not With Cardiovascular Outcomes in Patients With Acute Coronary Syndromes: Insights From the PLATO (Platelet Inhibition and Patient Outcomes) Trial

Background

Elevated levels of osteoprotegerin, a secreted tumor necrosis factor–related molecule, might be associated with adverse outcomes in patients with coronary artery disease. We measured plasma osteoprotegerin concentrations on hospital admission, at discharge, and at 1 and 6 months after discharge in a predefined subset (n=5135) of patients with acute coronary syndromes in the PLATO (Platelet Inhibition and Patient Outcomes) trial.

Methods and Results

The associations between osteoprotegerin and the composite end point of cardiovascular death, nonprocedural spontaneous myocardial infarction or stroke, and non–coronary artery bypass grafting major bleeding during 1 year of follow‐up were assessed by Cox proportional hazards models. Event rates of the composite end point per increasing quartile groups at baseline were 5.2%, 7.5%, 9.2%, and 11.9%. A 50% increase in osteoprotegerin level was associated with a hazard ratio (HR) of 1.31 (95% confidence interval [CI], 1.21–1.42) for the composite end point but was not significant in adjusted analysis (ie, clinical characteristics and levels of C‐reactive protein, troponin T, NT‐proBNP [N‐terminal pro‐B‐type natriuretic peptide], and growth differentiation factor‐15). The corresponding rates of non–coronary artery bypass grafting major bleeding were 2.4%, 2.2%, 3.8%, and 7.2%, with an unadjusted HR of 1.52 (95% CI, 1.36–1.69), and a fully adjusted HR of 1.26 (95% CI, 1.09–1.46). The multivariable association between the osteoprotegerin concentrations and the primary end point after 1 month resulted in an HR of 1.09 (95% CI, 0.89–1.33); for major bleeding after 1 month, the HR was 1.33 (95% CI, 0.91–1.96).

Conclusions

In patients with acute coronary syndrome treated with dual antiplatelet therapy, osteoprotegerin was an independent marker of major bleeding but not of ischemic cardiovascular events. Thus, high osteoprotegerin levels may be useful in increasing awareness of increased bleeding risk in patients with acute coronary syndrome receiving antithrombotic therapy.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00391872.

Associations of osteoprotegerin with coronary artery calcification among women with systemic lupus erythematosus and healthy controls

Objective We tested the hypothesis that higher circulating levels of osteoprotegerin (OPG) are related to higher levels of coronary artery calcification (CAC) among women with systemic lupus erythematosus (SLE) compared with healthy controls (HCs). Methods Among 611 women in two age- and race-matched SLE case-control studies, OPG was assayed in stored blood samples (HEARTS: plasma, n cases/controls = 122/124, and SOLVABLE: serum, n cases/controls = 185/180) and CAC was measured by electron beam computed tomography. Results In both studies, SLE patients had higher OPG and CAC levels than HCs. Higher OPG was associated with high CAC (>100 vs.100) among SLE, and with any CAC (>0 vs. 0) among HCs. Multivariable-adjusted OR (95% CI) for OPG tertile 3 vs. 1 was 3.58 (1.19, 10.76), p trend = 0.01 for SLE, and 2.28 (1.06, 4.89), p trend = 0.04 for HCs. Associations were attenuated when age-adjusted, but remained significant for HC women aged ≥ 40 and SLE women aged ≥ 50. ROC analyses identified 4.60 pmol/l as the optimal OPG cutpoint for predicting high CAC (>100) among SLE patients with sensitivity = 0.74 and specificity = 0.61, overall, but 0.92 and 0.52, respectively, for SLE patients aged ≥ 50. Conclusion Our cross-sectional results suggest that higher OPG levels are related to higher CAC levels among women with SLE vs. healthy controls.

Interdependence between osteoprotegerin and active von Willebrand factor in long-term cardiovascular mortality prediction in patients undergoing percutaneous coronary intervention

The interdependence of the predictive accuracy of serum osteoprotegerin (OPG) and von Willebrand factor (vWF) levels for long-term cardiovascular outcomes has not been investigated so far. This was a prospective observational cohort study in 361 patients with coronary artery disease undergoing percutaneous coronary intervention (PCI). Baseline levels of OPG, vWF, active vWF (act vWF) and ristocetin cofactor activity (vWF:RICO) were measured. Cardiovascular mortality was recorded over a median of five years. OPG concentrations >3.7 µg/ml emerged as the strongest predictor of cardiovascular (CV) death: 30 % of patients died during the five-year follow-up in this group, as compared to 10 % in patients with OPG ≤3.7 µg/ml (p<0.001). Act vWF had a significant prognostic impact on CV mortality when OPG levels were low (≤3.7 µg/ml): patients with act vWF concentration >1 µg/ml died in 14 %, whereas those with act vWF values ≤1 µg/ml had a mortality rate of 1 % (p=0.015). We stratified patients into three groups: high OPG, low OPG/high act vWF and low OPG/low act vWF. Patients with high OPG values had a 13-fold higher risk for CV death than those with low OPG/low act vWF concentrations (adj. HR: 12.6; 95 %CI: 1.7–94.7; p=0.014), and a two-fold higher risk as compared to those patients with low OPG/high act vWF concentrations (adj. HR: 2.0; 95 %CI: 1.1–3.7; p=0.03) in the adjusted Cox regression analysis. In conclusion, elevated OPG at the time of PCI was a strong independent predictor of five-years cardiovascular mortality, whereas act vWF had a significant prognostic impact on CV mortality when OPG levels were low.

Prediction of Fractures and Major Cardiovascular Events in Men Using Serum Osteoprotegerin Levels: The Prospective STRAMBO Study

Fragility fractures and cardiovascular diseases often coincide. However, data on shared risk factors and markers are scarce. Our aim was to assess the independent associations of serum osteoprotegerin (OPG) levels with the risk of fracture and cardiovascular outcomes (acute coronary syndrome, cardiac death) in older men. A cohort of 819 home-dwelling men aged 60 to 87 years was followed prospectively for 8 years. Serum OPG was measured at baseline by ELISA. Bone mineral density (BMD) at femoral neck and Trabecular Bone Score (TBS) were assessed by DXA. Clinical risk factors and Fracture Risk Assessment Tool (FRAX) were assessed. The incident events (self-reported peripheral fractures and acute coronary syndrome, cardiac death reported by a proxy) confirmed by a health professional were retained for the statistical analysis. Incident vertebral fractures were assessed on lateral DXA scans after 4 and 8 years. Hazard risk (HR) was assessed using the Cox model. After adjustment for FRAX corrected for femoral neck BMD and TBS, diabetes mellitus, ischemic heart disease, and prior falls, the risk of fracture was twofold higher in the highest versus the lowest OPG quartile (HR 2.35; 95% CI, 1.35 to 4.10). The risk of vertebral and nonvertebral fracture was higher in the highest versus the lowest OPG quartile (OR 2.76 [95% CI, 1.08 to 7.05] and HR 2.46 [95% CI, 1.23 to 4.92]). The risk of major osteoporotic fracture was higher in the fourth versus the first OPG quartile (HR 2.43; 95% CI, 1.16 to 5.10). The risk of cardiovascular outcome (adjusted for confounders) was higher in the highest versus the lowest OPG quartile (HR 3.93; 95% CI, 1.54 to 10.04). The risk of fracture and cardiovascular outcome was higher in the highest OPG quartile versus the lower quartiles combined (HR 2.06 [95% CI, 1.35 to 3.14] and HR 2.98 [95% CI, 1.60 to 5.54], respectively). In conclusion, in older men, higher serum OPG levels represent an independent risk factor for cardiovascular and fracture risk. © 2017 American Society for Bone and Mineral Research.

Serum osteoprotegerin in prevalent hemodialysis patients: associations with mortality, atherosclerosis and cardiac function

Background

To assess whether serum osteoprotegerin (OPG) and/or fetuin-A predict mortality and cardiovascular (CV) morbidity and mortality in hemodialysis patients.

Methods

Multicenter, observational, prospective study that included 220 hemodialysis patients followed up for up to 6 years. Serum OPG and fetuin-A levels were measured at baseline and their possible association with clinical characteristics, CV risk biomarkers, carotid ultrasonographic findings, as well as their association with overall and CV mortality and CV events were assessed.

Results

During a mean follow-up of 3.22 ± 1.91 years, there were 74 deaths (33.6%) and 86 new cardiovascular events. In the Kaplan-Meier survival analysis, the highest tertile of OPG levels was associated with higher overall mortality (p = 0.005), as well as a higher, although non-significant, incidence of CV events and CV mortality. In contrast, fetuin-A levels did not predict any of these events. OPG levels were directly associated with age, the Charlson comorbidity index (CCI), prevalent cardiovascular disease, carotid intima-media thickness, adiponectin, troponin-I and brain natriuretic peptide (BNP). OPG showed a negative correlation with left ventricular ejection fraction (LVEF) and phosphate levels. In the multivariate Cox proportional hazard analysis, all-cause mortality was associated with the highest tertile of OPG (HR:1.957, p = 0.018), age (HR:1.031, p = 0.036), smoking history (HR:2.122, p = 0.005), the CCI (HR:1.254, p = 0.004), troponin-I (HR:3.894, p = 0.042), IL-18 (HR:1.061, p < 0.001) and albumin levels (HR:0.886, p < 0.001). In the bootstrapping Cox regression analysis, the best cut-off value of OPG associated with mortality was 17.69 pmol/L (95%CI: 5.1–18.02).

Conclusions

OPG, but not fetuin-A levels, are independently associated with overall mortality, as well as clinical and subclinical atherosclerosis and cardiac function, in prevalent hemodialysis patients.

Electronic supplementary material

The online version of this article (10.1186/s12882-017-0701-8) contains supplementary material, which is available to authorized users.

Circulating osteoprotegerin is associated with chronic kidney disease in hypertensive patients

Background

Osteoprotegerin (OPG) is a glycoprotein that plays an important regulatory role in the skeletal, vascular, and immune system. It has been shown that OPG predicts chronic kidney disease (CKD) in diabetic patients. We hypothesized that OPG could be a risk marker of CKD development also in non-diabetic hypertensive patients.

Methods

A case-control study was carried out to measure circulating OPG levels in 42 hypertensive patients with CKD and in 141 hypertensive patients without CKD. A potential relationship between OPG and the presence of CKD was investigated and a receiver-operating characteristic (ROC) curve was designed thereafter to identify a cut-off value of OPG that best explained the presence of CKD. Secondly, to evaluate whether OPG increase could affect the kidney, 18 C57BL/6J mice were randomized to be treated with saline or recombinant OPG every 3 weeks for 12 weeks.

Results

Circulating OPG levels were significantly higher in hypertensive patients with CKD, and there was a significant inverse association between OPG and renal function, that was independent from other variables. ROC analysis showed that OPG levels had a high statistically predictive value on CKD in hypertensive patients, which was greater than that of hypertension. The OPG best cut-off value associated with CKD was 1109.19 ng/L. In the experimental study, OPG delivery significantly increased the gene expression of pro-inflammatory and pro-fibrotic mediators, as well as the glomerular nitrosylation of proteins.

Conclusions

This study shows that OPG is associated with CKD in hypertensive patients, where it might have a higher predictive value than that of hypertension for CKD development. Secondly, we found that OPG delivery significantly increased the expression of molecular pathways involved in kidney damage. Further longitudinal studies are needed not only to evaluate whether OPG predicts CKD development but also to clarify whether OPG should be considered a risk factor for CKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0625-3) contains supplementary material, which is available to authorized users.

Can Brain Natriuretic Peptides and Osteoprotegerin Serve As Biochemical Markers for the Detection of Aortic Pathology in Children and Adolescents with Turner Syndrome?

Turner syndrome (TS) is a chromosomal disorder that affects 1:2,000 females. It results from either the complete or partial loss of the X chromosome as well as other aberrations. Clinical features of TS include short stature, delayed puberty, and congenital cardiac malformations. TS children also have an increased prevalence of cardiometabolic risk factors, which predisposes them to complications like coronary artery disease, cerebrovascular-related deaths, and aortic dissection. Early cardiac imaging, such as echocardiography and cardiac magnetic resonance imaging, are recommended to detect underlying aortic pathology. However, these modalities are limited by cost, accessibility, and are operator dependent. In view of these shortcomings, alternative methods, like vascular biomarkers, are currently being explored. There are only a few studies that have examined the relationship between B-type natriuretic peptide (BNP), N-terminal pro BNP (NT pro-BNP), and osteoprotegerin (OPG) and aortic disease in TS, and thus the data are only in proof-of-concept stages. Further meticulous longitudinal studies are required before BNP, NT pro-BNP, and OPG are used as vascular biomarkers for the detection of aortic disease in childhood and adolescent TS.

Plasma levels of sRANKL and OPG are associated with atherogenic cytokines in patients with intermediate cardiovascular risk

Osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) are regulators of bone remodeling, but are also considered to play important roles in coronary artery disease (CAD). This study evaluated potential associations of soluble (s) RANKL and OPG with atherosclerosis-relevant cytokines. Blood was collected from 414 individuals who presented to our hospital with intermediate likelihood for CAD for further examination. Plasma concentrations of total sRANKL, OPG, and 20 cytokines were measured using sandwich-type enzyme-linked immunoassays (ELISAs; OPG and sRANKL) and Luminex laser-based fluorescence analysis and correlated with each other. The plasma levels of interferon-γ (IFN-γ) and the T-helper cell 2 cytokines interleukin-4 (IL-4) and IL-13 showed a positive correlation with sRANKL. The association with sRANKL levels was negative for IFN-γ-induced protein-10 (IP-10) and monocyte chemotactic protein-1 (MCP-1). The strongest independent association with sRANKL in multivariable analyses was found for IFN-γ (positive) and IP-10 (negative), while IL-13 showed a positive and independent association with OPG plasma levels. OPG and sRANKL plasma levels correlate strongly and independently with specific circulating atherosclerosis-related cytokines in patients with intermediate cardiovascular risk.

Osteoprotegerin as a marker of cardiovascular risk in children and adolescents with type 1 diabetes

BACKGROUND

Elevated osteoprotegerin (OPG) levels have been reported in patients with diabetes complications. We investigated whether plasma OPG levels can be used as a marker of cardiovascular risk in children and adolescents with type 1 diabetes (T1D).

METHODS

Plasma blood samples were obtained from 243 subjects (143 children and adolescents with T1D and 100 healthy controls). OPG concentrations were measured by enzyme-linked immunosorbent assay (ELISA) method. All data were analyzed by using PASW statistics 18.

RESULTS

A significant higher plasma OPG level was found in children with T1D compared to controls (p < 0.001). A significant increase of OPG levels has been related to the glucose level ≥ 7 mmol/L (2.44 [0.01-6.22] vs. 2.16 [0.13-6.22] pmol/L, p = 0.019), microalbuminuria ≥ 30 mg/24 h (3.71 [0.160-6.03] vs. 2.26 [0.01-6.22] pmol/L, p < 0.001), and cystatin-C ≥ 0.789 mg/L (2.64 [0.37-6.22] vs. 2.11 [0.01-5.82] pmol/L, p < 0.001). We noted a significant higher frequency of children with increased cystatin-C levels in the group with elevated plasma level of OPG compared with those with normal levels (49 vs. 18%, respectively) with an odds ratio (OR) = 4.42 [1.41-13.84] (p = 0.006). We showed a significant increase of OPG levels when the number of cardiovascular risk factors exceeds 3 (p = 0.001).

CONCLUSION

OPG may be a potential biomarker of cardiovascular risk in T1D. Implementation of OPG determination in the clinical laboratory setting would be useful in order to better stratify patients and to assess the most adequate treatment.

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.

Osteoprotegerin levels in ST-elevation myocardial infarction: Temporal profile and association with myocardial injury and left ventricular function

Background

Elevated levels of osteoprotegerin (OPG) have been associated with adverse outcomes in ST-elevation myocardial infarction (STEMI). However, the role of OPG in myocardial injury and adverse remodeling in STEMI patients remains unclear. The aims of this observational cohort study were to evaluate: 1) the temporal profile of OPG during STEMI, 2) possible associations between OPG measured acutely and after 4 months, with infarct size, adverse left ventricular (LV) remodeling, microvascular obstruction (MVO) and myocardial salvage and 3) the effect of heparin administration on OPG levels.

Methods

Blood samples were drawn repeatedly from 272 STEMI patients treated with primary percutaneous coronary intervention (PCI). Cardiac magnetic resonance imaging (CMR) was performed in the acute phase and after 4 months. The effect of heparin administration on OPG levels was studied in 20 patients referred to elective coronary angiography.

Results

OPG levels measured acutely were significantly higher than Day 1 and during follow-up. OPG levels were correlated with age. No association was found between early OPG levels and CMR measurements at 4 months. Patients with >median OPG levels measured at Day 1 had larger final infarct size, lower LV ejection fraction (LVEF) at 4 months and higher frequency of MVO. There were no associations between OPG and change in end-diastolic volume or myocardial salvage. OPG remained associated with infarct size and LVEF after adjustment for relevant covariates, except peak troponin T and CRP. A 77% increase in OPG levels following heparin administration was found in patients undergoing elective coronary angiography.

Conclusions

OPG was found to be associated with myocardial injury, but not with LV remodeling or myocardial salvage. The use of OPG as a biomarker in STEMI patients seems to be limited by a strong association with age, confounding effect of heparin administration, and little additive value to established biomarkers.

Investigation of OPG/RANK/RANKL Genes as a Genetic Marker for Cardiac abnormalities in Thalassemia Major Patients

OBJECTIVE

The aim of the study was to investigate the role of osteoprotegerin (OPG)/RANK/RANKL variants in left ventricular hypertrophy (LVH) and diastolic dysfunction in thalassemia major patients MATERIALS AND METHOD: One hundred and five beta-thalassemia patients who were older than 10 years of age were enrolled for the study. Two-dimensional and M-mode echocardiography analysis was done in all patients. Genotyping for OPG [rs2073617 (950 T>C), rs2073618 (1181G>C)], RANK [(rs1805034(+34694 C>T), rs12458117 (+34901 G>A) and rs75404003 (+35966insdelC)], and RANKL (rs2277438, rs9594782) variants was done using the PCR-RFLP method. Serum OPG levels were estimated by ELISA.

RESULTS

Mean age of patients was 16.36 ± 5.08 years. LVH and diastolic dysfunction was present in 33 (31.4%) and 24 (22.8%) patients, respectively. Thalassemia patients having minor allele of OPG rs2073618, RANK rs75404003 and RANKL rs9594782 SNPs were at high risk for LVH as suggested by high odds ratio of 2.470, 3.783, and 2.148, respectively; however, none of the SNPs tested were statistically significantly associated after applying Bonferroni corrections for multiple testing adjustment. No significant association of any SNP with diastolic dysfunction was observed. Serum OPG levels were found significantly higher in thalassemia patients with diastolic dysfunction (P  =  0.006).

CONCLUSION

OPG rs2073618, RANK rs75404003, and RANKL rs9594782 SNPs may predispose LVH in thalassemia patients. Patients with diastolic dysfunction showed increased levels of serum OPG.

Correlation research between osteoporosis and left ventricular hypertrophy in older men

INTRODUCTION

The aim of the study was to correlate between osteoporosis and left ventricular hypertrophy (LVH) in older men.

MATERIAL AND METHODS

One hundred and forty-six cases of senile male subjects were selected and divided into a normal bone mineral density group, an osteopenia group, and an osteoporosis group based on bone mineral density (BMD). Detailed history inquiry and clinical examination were used to determine biochemical indicators. Femoral neck BMD and lumbar BMD were determined. Electrocardiography was performed to calculate the left ventricular mass index (LVMI). One-way analysis of variance and multiple linear regression analysis were performed.

RESULTS

With the bone mass reduced, LVMI was gradually increased (p < 0.05), incidence of left ventricular hypertrophy was increased, and there were significant differences (p < 0.05). With LVMI as the dependent variable, multiple linear regression analysis showed that lumbar bone density, body mass index, age and serum creatinine were associated with LVMI independently (p < 0.05).

CONCLUSIONS

In patients with osteoporosis and osteopenia, LVH rates were much higher than in normal bone mineral density patients. Moreover, there might be a relationship between osteoporosis and LVH.

Osteoprotegerin in Chronic Kidney Disease: Associations with Vascular Damage and Cardiovascular Events

Vascular injury and dysfunction contribute to cardiovascular disease, the leading cause of death in patients with chronic kidney disease (CKD). Osteoprotegerin (OPG) is a soluble member of the tumor necrosis factor receptor superfamily that has been linked to atherogenesis and endothelial dysfunction. Elevated circulating OPG levels predict future cardiovascular events (CVE). Our aim was to evaluate the determinants of circulating OPG levels, to investigate the relationship between OPG and markers of vascular damage and to test whether OPG improves risk stratification for future CVE beyond traditional and renal-specific risk factors in a CKD population. 291 patients with CKD stage 1-5 not on dialysis were included in the study. In the multivariate analysis, OPG was a significant predictor for flow-mediated dilatation, but not for carotid intima media thickness levels. During follow-up (median 36 months, IQR = 32-42 months), 87 patients had CVE. In the Cox survival analysis, OPG levels were independently associated with CVE even after adjustment for traditional and renal-specific cardiovascular risk factors. The addition of OPG to a model based on commonly used cardiovascular factors significantly improved the reclassification abilities of the model for predicting CVE. We show for the first time that OPG improves risk stratification for CVE in a non-dialysis CKD population, above and beyond a model with established traditional and renal-specific cardiovascular risk factors, including estimated glomerular filtration rate and fibroblast growth factor 23.

Mitral valve endothelial cells secrete osteoprotegerin during endothelial mesenchymal transition

AIMS

Mitral valve prolapse (MVP) has a prevalence of 3% in the general population, affecting >176 million people worldwide. Despite this, little is known about the molecular and cellular mechanisms involved in the progression of MVP and surgical intervention is the only available option. In this study we investigated the role of osteoprotegerin (OPG) during endothelial to mesenchymal transition (EndMT) in MVP.

METHODS AND RESULTS

VECs and VICs were isolated from posterior mitral valve leaflets of patients undergoing mitral valve repair (n=25). Plasma was collected from 57 subjects (29 controls and 28 MVP patients). Overexpression of OPG during EndMT followed by autocrine effects characterised by reactive oxygen species increment and accelerated migration was documented. In addition, OPG increased VIC proliferation. Finally, OPG plasma levels were significantly higher in MVP patients compared to control subjects and the area under the ROC curve was 0.92.

CONCLUSION

EndMT has been recognised as a possible pathological mechanism for MVP. For the first time, we report the involvement of OPG in cellular and molecular changes in MVP isolated cells. In addition, we detected elevated circulating OPG levels in MVP patients when compared to controls, which supports the hypothesis that OPG is involved in MVP development and progression.