Serum osteoprotegerin levels and long-term prognosis in patients with stable angina pectoris

Plasma osteoprotegerin predicts adverse cardiovascular events in stable coronary artery disease: the PEACE trial

Background

Osteoprotegerin (OPG) is a secretory glycoprotein and participates in the progression of atherosclerotic lesions. We aim to explore the relationship between OPG and the prognosis of coronary artery disease (CAD).

Methods

Plasma OPG concentrations were measured in 3,766 patients with stable CAD enrolled in the PEACE trial. The PEACE trial (NCT00000558) group followed up the patients and examined their future clinical outcomes.

Results

In summary, 208 (5.5%) primary outcomes occurred, 295 patients (7.8%) died from all-cause death, 128 (3.4%) died from cardiovascular causes, and 94 (2.5%) experienced heart failure during a median follow-up of 1,892 days. In addition, we found that higher plasma levels of OPG were associated with a higher incidence of all-cause death, cardiovascular death, and heart failure, even after adjusting clinical cofounders.

Conclusion

It was demonstrated that elevated plasma OPG levels were associated with an increased incidence of all-cause death, cardiovascular death, and heart failure in patients with stable CAD.

Systematic Review Registration

https://clinicaltrials.gov/ct2/show/NCT00000558?term=NCT00000558&draw=2&rank=1, identifier: NCT00000558.

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.

Osteoprotegerin Is a Better Predictor for Cardiovascular and All-Cause Mortality than Vascular Calcifications in a Multicenter Cohort of Patients on Peritoneal Dialysis

The purpose of this study was to compare vascular calcification (VC), serum osteoprotegerin (OPG) levels, and other biochemical markers to determine their value as available predictors of all-cause and cardiovascular (CV) mortality in patients on peritoneal dialysis (PD). A total of 197 patients were recruited from seven dialysis centers in Mexico City. VC was assessed with multi-slice computed tomography, measured using the calcification score (CaSc). OPG, albumin, calcium, hsC-reactive protein, phosphorous, osteocalcin, total alkaline phosphatase, and intact parathormone were also analyzed. Follow-up and mortality analyses were assessed using the Cox regression model. The mean age was 43.9 ± 12.9 years, 64% were males, and 53% were diabetics. The median OPG was 11.28 (IQR: 7.6−17.4 pmol/L), and 42% of cases had cardiovascular calcifications. The median VC was 424 (IQR:101−886). During follow-up (23 ± 7 months), there were 34 deaths, and 44% were cardiovascular in origin. In multivariable analysis, OPG was a significant predictor for all-cause (HR 1.08; p < 0.002) and CV mortality (HR 1.09; p < 0.013), and performed better than VC (HR 1.00; p < 0.62 for all-cause mortality and HR 1.00; p < 0.16 for CV mortality). For each mg/dL of albumin-corrected calcium, there was an increased risk for CV mortality, and each g/dL of albumin decreased the risk factor for all-cause mortality. OPG levels above 14.37 and 13.57 pmol/L showed the highest predictive value for all-cause and CV mortality in incident PD patients and performed better than VC.

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.

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.

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.

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.

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.

Effects of Salt Loading on Plasma Osteoprotegerin Levels and Protective Role of Potassium Supplement in Normotensive Subjects

BACKGROUND

Excess dietary salt is strongly correlated with cardiovascular disease, morbidity, and mortality. Conversely, potassium likely elicits favorable effects on cardiovascular disorders. In epidemiological studies, increased plasma osteoprotegerin (OPG) concentrations are associated with atherosclerosis and vascular deaths. Our study was designed to examine the effects of salt intake and potassium supplementation on plasma OPG levels in normotensive subjects.Methods and Results:The 18 normotensive subjects were selected from a rural community in China. They were sequentially maintained on low-salt diet for 7 days (3 g/day, NaCl), high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for 7 days (18 g/day of NaCl+4.5 g/day of KCl). High-salt intake enhanced plasma OPG levels (252.7±13.9 vs. 293.4±16.1 pg/mL). This phenomenon was abolished through potassium supplementation (293.4±16.1 vs. 235.1±11.3 pg/mL). Further analyses revealed that the OPG concentration positively correlated with 24-h urinary sodium excretion (r=0.497, P<0.01). By contrast, OPG concentration negatively correlated with 24-h urinary potassium excretion (r=0.594, P<0.01).

CONCLUSIONS

Salt loading can enhance the production of circulating OPG. Potassium supplementation can reverse the effects of excessive OPG. Our study results may improve our understanding of the roles of salt and potassium in the risk of cardiovascular disorders.

Assessing Risk in Patients with Stable Coronary Disease: When Should We Intensify Care and Follow-Up? Results from a Meta-Analysis of Observational Studies of the COURAGE and FAME Era

Background. A large number of clinical and laboratory markers have been appraised to predict prognosis in patients with stable angina, but uncertainty remains regarding which variables are the best predictors of prognosis. Therefore, we performed a meta-analysis of studies in patients with stable angina to assess which variables predict prognosis. Methods. MEDLINE and PubMed were searched for eligible studies published up to 2015, reporting multivariate predictors of major adverse cardiac events (MACE, a composite endpoint of death, myocardial infarction, and revascularization) in patients with stable angina. Study features, patient characteristics, and prevalence and predictors of such events were abstracted and pooled with random-effect methods (95% CIs). Major adverse cardiovascular event (MACE) was the primary endpoint. Results. 42 studies (104,559 patients) were included. After a median follow-up of 57 months, cardiovascular events occurred in 7.8% of patients with MI in 6.2% of patients and need for repeat revascularization (both surgical and percutaneous) in 19.5% of patients. Male sex, reduced EF, diabetes, prior MI, and high C-reactive protein were the most powerful predictors of cardiovascular events. Conclusions. We show that simple and low-cost clinical features may help clinicians in identifying the most appropriate diagnostic and therapeutic approaches within the broad range of outpatients presenting with stable coronary artery disease.

Association between Body Mass Index, Asymmetric Dimethylarginine and Risk of Cardiovascular Events and Mortality in Norwegian Patients with Suspected Stable Angina Pectoris

Background

Asymmetric dimethylarginine (ADMA) is associated with increased risk of atherosclerotic cardiovascular disease and mortality through inhibition of nitrogen oxide (NO) synthesis. As positive correlations between serum concentrations of NO and body mass index (BMI) have been observed, we aimed to explore whether the potential associations between plasma ADMA levels and the risk of acute myocardial infarction (AMI) and mortality were modified by BMI.

Methods

Multivariable Cox proportional hazard models were used to estimate the hazard ratios (HR) for AMI, cardiovascular death and all-cause mortality according to baseline plasma ADMA levels in 4122 patients with suspected stable angina pectoris. Analyses were subsequently repeated in patients with BMI below (low BMI) or above (high BMI) median.

Results

A total of 2982 patients (72%) were men. Median (range) age, plasma ADMA level and BMI were 62 (21–88) years, 0.54 (0.10–1.25) μmol/L and 26.3 (18.5–54.3) kg/m², respectively. During a mean (standard deviation) follow-up time of 4.7 (1.4) years, 337 (8%) patients suffered from an AMI, 300 (7%) died, whereof 165 (55%) due to cardiovascular disease. Each 0.1 μmol/L increment in plasma ADMA level was associated with an increased risk of AMI (HR (95% CI) 1.21 (1.08, 1.35) and cardiovascular death 1.30 (1.13, 1.49) in participants with low BMI only. Interactions were significant for AMI (p = 0.04) and CV death (p = 0.03). BMI did not modify the association between plasma ADMA levels and all-cause mortality.

Conclusion

Plasma ADMA levels were associated with risk of AMI and cardiovascular death among patients with low BMI only.

Serum trans fatty acids, asymmetric dimethylarginine and risk of acute myocardial infarction and mortality in patients with suspected coronary heart disease: a prospective cohort study

Background

Trans fatty acids (TFAs) have been found to impair flow mediated vasodilation and nitric oxide (NO) production. We sought to examine if serum TFA levels are associated with plasma levels of the NO inhibitor asymmetric dimethylarginine (ADMA) and if possible relationships between serum TFA and cardiovascular morbidity or mortality are mediated or modified by plasma ADMA levels.

Methods

The cohort included patients who underwent coronary angiography for suspected coronary heart disease in 2000–2001. Serum trans 16:1n7 and trans 18:1 isomers were determined by gas liquid chromatography and the summation of these two TFAs is reported as TFA (percentage by weight (wt%) or concentration). Associations between TFAs and ADMA were estimated by calculating the Spearman’s rank correlation coefficient (ρ), and risk associations with AMI, cardiovascular death and all-cause mortality across quartiles of TFAs (wt% or concentration) were explored by Cox modeling.

Results

A total of 1364 patients (75 % men) with median (25^th,75^th percentile) age 61 (54, 69) years, serum TFA 0.46 (0.36, 0.56) wt% and plasma ADMA 0.59 (0.50, 0.70) μmol/L were studied. Serum TFA levels (ρ = 0.21, p < 0.001), trans 16:1n7 (ρ = 0.22, p < 0.001) and trans 18:1 (ρ = 0.20, p < 0.001) levels were significantly correlated with plasma ADMA levels. During the median (25^th,75^th percentile) follow-up time of 5.8 (4.5, 6.4) years, 129 (9.5 %) patients experienced an AMI, 124 (9.1 %) died, whereof 66 (53 %) due to cardiovascular causes. After multivariate adjustments no significant associations between serum TFA levels (wt% or concentration) and incident AMI, CV death and all-cause mortality were observed. Similar results were obtained when repeating the analyses with trans 16:1n7 and trans 18:1 individually. Plasma ADMA levels did not significantly modify the associations between TFA levels and outcomes.

Conclusions

Serum TFA levels were positively correlated with plasma ADMA levels. After multivariate adjustments, TFAs were not associated with incident AMI or mortality, and associations were not influenced by ADMA.

Trial registration

Clinicaltrials.gov Identifier: NCT00354081

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-016-0204-9) contains supplementary material, which is available to authorized users.

Osteoprotegerin in Turner syndrome - relationship to aortic diameter

BACKGROUND

Cardiovascular disease is a cardinal trait of Turner syndrome (TS), causing half of the threefold excess mortality. As osteoprotegerin (OPG) is a potential biomarker of cardiovascular disease, this cross-sectional and prospective study aimed at elucidating OPG levels in TS and its relationship to aortic diameter as well as validated cardiovascular risk markers.

METHODS

Adult women with TS (n = 99) were examined thrice (mean follow-up 4·7 ± 0·5 years), and 68 age-matched healthy female controls were examined once. Aortic diameter was assessed by cardiovascular magnetic resonance. Twenty-four-hours blood pressure monitoring and biochemical assessments were also performed.

RESULTS

Osteoprotegerin levels (median with range) were lower in TS (777 [326-10 569] ng/l) compared with controls (979 [398-1987] ng/l; P < 0·05) and did not change during follow-up. The OPG concentration was higher among women with TS older than 50 years of age (996 [542-4996] vs 756 [326-10 569] ng/l; P < 0·05) with a trend towards a higher OPG in TS who were on antihypertensive medication (938 [490-2638] vs 752 [326-10 569] ng/l; P = 0·09). Contrary to controls, OPG levels correlated with BSA-indexed aortic diameter (r = 0·31-0·45; P < 0·05), age (r = 0·29; P < 0·05) and high-sensitivity C-reactive protein (r = 0·23; P = 0·02) and inversely with BSA (r = -0·20; P < 0·05), weight (r = -0·23; P < 0·05) and plasma oestradiol levels (r = -0·34; P < 0·05).

CONCLUSION

Levels of OPG are lower in TS and correlate with aortic diameter, age, BSA, weight and oestradiol in TS, but not controls. Future studies are needed to assess whether OPG may serve as a biomarker of aortic or cardiovascular disease in TS.

Glycated hemoglobin and long-term prognosis in patients with suspected stable angina pectoris without diabetes mellitus: a prospective cohort study

OBJECTIVE

Associations of glycated hemoglobin A1c (HbA1c) levels to incident coronary and cardiovascular events among non-diabetic patients with coronary artery disease are unclear. We investigated relations of HbA1c to long-term prognosis in such patients.

METHODS

A prospective cohort of 2519 patients undergoing elective coronary angiography for suspected stable angina pectoris (SAP) was divided into pre-defined categories according to HbA1c (%) levels (<5.0, 5.0-5.6 (reference), 5.7-6.4), and followed for median 4.9 years. The primary end-point was major coronary events (including non-fatal and fatal acute myocardial infarctions, and sudden cardiac death). Secondary end-points were death from cardiovascular disease (CVD) and all-cause mortality. Hazard ratios (HRs) (95% confidence intervals [CIs]) were obtained by Cox regression.

RESULTS

Median age at inclusion was 62 years, 73% were males, median HbA1c was 5.6% and random plasma-glucose 5.4 mmol/L. After multivariate adjustment, HbA1c levels within the pre-diabetic range were not associated with risk of major coronary events, HR (95% CI): 1.13 (0.79-1.62); P=0.49, death from CVD or all-cause mortality HR (95% CI): 0.95 (0.55-1.66) and 1.04 (0.70-1.53), respectively; P≥0.85. Similarly, there was no significant association between HbA1c values within the lowest category and risk of study outcomes, (P≥0.18).

CONCLUSION

In non-diabetic patients with suspected SAP, there was no overall association between HbA1c levels and prognosis, questioning an independent role of glycemia in the pathogenesis of atherosclerotic complications in these patients.

Lipocalin-type prostaglandin D synthase is not a biomarker of atherosclerotic manifestations

OBJECTIVE

Over the last decades Lipocalin-type prostaglandin D synthase (L-PGDS), Osteoprotegerin (OPG), Osteopontin (OPN) and Pregnancy associated plasma protein A (PAPP-A) have been reported to be associated with coronary artery disease, and L-PGDS has been proposed as a potential new diagnostic tool in the setting of stable coronary artery disease. We set out to investigate if measurement of concentrations of these biomarkers could be used to differentiate between four groups of individuals with different atherosclerotic manifestations.

METHODS

A total of 120 individuals from four equal gender- and age-matched groups were studied: (i) no previous cardiovascular disease (CVD) and no coronary calcifications [CAC-negative group], (ii) no previous CVD but evidence of severe coronary calcifications [CAC-positive group], (iii) acute coronary syndrome [ACS-group], and (iv) clinical stable patients with CVD, who were referred for cardiovascular surgery [CVD-group]. Concentrations of L-PGDS, OPG, OPN and PAPP-A were analyzed and compared between the four groups.

RESULTS

We did not find any significant differences in L-PGDS concentrations between the four groups (p = 0.32). OPG concentrations differed significantly (p = 0.003), with the highest concentration observed in ACS patients. Considering OPN (p = 0.12) and PAPP-A (p = 0.53) their concentrations between groups did not differ significantly.

CONCLUSION

The main message from this study is the observation that L-PGDS based on a single blood test appears to be less valuable than previously proposed in identification of patients with coronary artery disease. However, ACS patients have higher OPG concentrations than patients with different manifestations of stable atherosclerosis. Neither OPN nor PAPP-A concentrations differed between groups.

The role of osteoprotegerin in cardiovascular disease

Osteoprotegerin (OPG) is a 401 amino acid N-glycosylated protein, which is highly expressed in a large number of tissues. OPG mainly binds to two ligands, i.e. RANKL (receptor activator of nuclear factor κB ligand) and TRAIL (tumor necrosis factor- related apoptosis-inducing ligand). Upon binding to the former ligand, OPG inhibits the activation of osteoclasts and promotes apoptosis of osteoclasts, whereas the binding of OPG with TRAIL prevents apoptosis of tumor cells. There is now emerging evidence that OPG participates in the pathogenesis of atherosclerosis and cardiovascular diseases by amplifying the adverse effects of inflammation and several traditional risk factors such as hyperlipidemia, endothelial dysfunction, diabetes mellitus, and hypertension. Some epidemiological studies also showed a positive association between OPG levels and cardiovascular morbidity and mortality. The aim of this article is to provide an overview of the main biochemical, physiological, and pathological aspects of OPG biology in cardiovascular disease.

Osteoprotegerin as a marker of atherosclerosis in diabetic patients

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

[Denosumab for treatment of postmenopausal osteoporosis]

BACKGROUND

Treatment with bisphosphonates reduces the risk of new fractures and is the treatment of choice for osteoporosis. Denosumab inhibits bone resorption via a different mechanism than bisphosphonates, and is a new option in the treatment of osteoporosis. In this paper we give an overview of the mode of action and clinical effects.

MATERIAL AND METHODS

The paper is based on a non-systematic literature search in Pubmed/Medline.

RESULTS

Denosumab is a human monoclonal antibody to receptor-activated nuclear factor kappa B (RANKL), a member of the TNF family that is formed in the osteoblast. Binding to RANKL results in reduced recruitment and activity of osteoclasts. Denosumab 60 mg given subcutaneously every six months is shown to inhibit bone resorption to a greater degree than bisphosphonates. In a three-year study of 7,868 women with postmenopausal osteoporosis, a reduction in the relative risk of vertebral, non-vertebral and hip fractures compared to placebo was found (68. 20 and 40 %, correspondingly). In the clinical trials with denosumab, the safety profile was similar to placebo, except for a slightly higher incidence of cellulitis and exanthema. Denosumab has also shown promising skeletal effects in the treatment of cancer and rheumatoid arthritis.

INTERPRETATION

Treatment with denosumab has an effect on postmenopausal osteoporosis and may be an alternative to treatment with bisphosphonates. There are few adverse effects and it is simple to administer.

Plasma osteoprotegerin levels and long-term prognosis in patients with intermediate coronary artery lesions

BACKGROUND

Osteoprotegerin (OPG) is a member of the tumor necrosis factor superfamily and plays an important regulatory role in the skeletal, immune, and vascular systems. Intermediate coronary artery lesions that have a diameter stenosis of approximately 20%-70% might cause serious consequences. However, the prognostic value of plasma OPG levels in patients with intermediate coronary artery lesions has been less reported.

HYPOTHESIS

We hypothesized that OPG is a predictive marker of prognosis of intermediate coronary artery lesions.

METHODS

A prospective study was performed on 890 patients with intermediate (20%-70%) coronary lesions. The median age was 62 years (25th and 75th percentiles, 55 and 70 years, respectively) and 67.2% were male. Fasting blood was sampled at baseline. The primary clinical endpoint was a composite of readmission due to angina pectoris, nonfatal myocardial infarction, revascularization, and cardiovascular death.

RESULTS

During a median follow-up of 24 months, events occurred in 11.1% of the patients. Of these patients, 7.9% were readmitted for angina pectoris, 1.5% received revascularization, 0.7% suffered nonfatal myocardial infarction, and 1.0% died. The plasma levels of OPG (median, 5304.7 pg/mL vs 2993.4 pg/mL, P<0.001) and high-sensitivity C-reactive protein (median, 4.8 mg/L vs 2.6 mg/L, P<0.001) were higher in patients with events than those without events. After adjusting for traditional risk factors such as age, gender, smoking, hypertension, diabetes, dyslipidemia, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein, percent area stenosis, and drug administration, a multivariate Cox proportional hazard analysis showed that higher OPG levels were an independent predictive factor of the composite clinical endpoint (hazard ratio: 2.49, 95% confidence interval: 1.26-4.89, fourth quartile vs first quartile).

CONCLUSIONS

The higher level of OPG is an independent predictive factor of prognosis in patients with intermediate coronary lesions.