Serum sclerostin as a potential novel biomarker for heart valve calcification in patients with chronic kidney disease

Exploring the Role of Sclerostin as a Biomarker of Cardiovascular Disease and Mortality: A Scoping Review

Sclerostin is most recognized for its role in controlling bone formation; however, it is also expressed in the heart, aorta, coronary, and peripheral arteries. Human studies have associated high circulating sclerostin levels with the presence of different cardiovascular diseases (CVD), surrogate CVD markers, and a high risk of cardiovascular events in some populations. However, this is still a matter of scientific debate, as the results have been very heterogeneous among studies. In the present review, the association between serum sclerostin levels and CVD and/or cardiovascular mortality was analyzed. For this purpose, a scoping review was performed in which articles measuring serum sclerostin levels and cardiovascular risk in patients were selected. Eleven articles answered the research question; of these articles, 8/11 evaluated the association between sclerostin and CVD, of which 4/8 found a positive association, 2/8 found a negative association, and 2/8 found no association between variables. Five (5/11) of the articles included in the study evaluated cardiovascular mortality, of which 3/5 found a positive association, 1/5 found a negative association, and 1/5 found no association between variables. In conclusion, we did not find sufficient results to be able to demonstrate an association between elevated sclerostin levels and the development of CVD and/or cardiovascular mortality in the general population due to heterogeneity in the results. However, there seems to be a tendency to consider increased sclerostin levels as a risk factor for both the development of cardiovascular events and cardiovascular mortality in specific populations. Further studies in this field will help to solve some of the inconsistencies found during this scoping review and allow for the future use of sclerostin measurement as a strategy in the prevention and diagnosis of CVD and/or cardiovascular mortality.

Cardiac Rehabilitation Improves Long-Term Prognosis for People with Chronic Kidney Disease Undergoing Percutaneous Coronary Intervention: A Propensity Matching Analysis

OBJECTIVES

According to researches, many people with chronic kidney disease (CKD) had the higher incidence rate and mortality rate of coronary artery disease (CAD) after percutaneous coronary intervention than those who did not receive percutaneous coronary intervention, while coronary rehabilitation was beneficial for patients who received percutaneous coronary intervention I. This study aims to analyze whether coronary rehabilitation was beneficial to patients with CKD after percutaneous coronary intervention. Patients and Methods. A retrospective survey was used to collect clinical data of patients undergoing percutaneous coronary intervention due to CAD, and CKD patients were screened for further analysis. According to whether patients had received coronary rehabilitation treatment, research subjects were divided into two groups, the coronary rehabilitation group and the noncoronary rehabilitation group. The baseline characteristics of the propensity score matching between the two groups were compared. Survival analysis used the Cox hazard ratio (HR) model as regression method to compare the relative risk of the endpoints in the coronary rehabilitation group and the noncoronary rehabilitation group.

RESULTS

From January 2007 to January 2012, a total of 246 CKD patients treated with percutaneous coronary intervention were included in this study, and 106 of them obtained coronary rehabilitation after surgery. After propensity score matching, there were 89 pairs of patients in the two groups who had no significant difference in demographic and clinical characteristics (all P > 0.05). CKD patients receiving coronary rehabilitation had a significant reduction in all-cause mortality (HR 0.465, 95% CI 0.233-0.926, P=0.029) and cardiac complications (HR 0.532, 95% CI 0.287-0.984, P=0.044). Survival analysis showed that the survival rate of the coronary rehabilitation group was significantly higher than that of the noncoronary rehabilitation group (P=0.024).

CONCLUSIONS

For CKD patients undergoing percutaneous coronary intervention, receiving cardiac rehabilitation can significantly improve long-term survival and reduce cardiac events.

Relation of Wnt Signaling Pathway Inhibitors (Sclerostin and Dickkopf-1) to Left Ventricular Mass Index in Maintenance Hemodialysis Patients

BACKGROUND

Left ventricular hypertrophy (LVH) is common in hemodialysis (HD) patients. It predicts poor prognosis. Several inhibitors regulate Wnt canonical pathways like Dickkopf-related protein-1 (Dkk-1) and sclerostin.

OBJECTIVES

To investigate the relationship between serum sclerostin, Dkk-1, left ventricular mass (LVM), and LVM index (LVMI) in HD patients.

METHODS

This is a cross-sectional study including 65 HD patients in our HD unit. Patients were divided into two groups according to LVMI (group 1 with LVMI < 125 gm/m2 (N = 29) and group 2 with LVMI > 125 gm/m2 (N = 36)). Echocardiographic evaluation of the LVM, aortic, and mitral valves calcification (AVC and MVC) was done. Serum levels of sclerostin and Dkk-1 and patients' clinical and biochemical data were recorded.

RESULTS

Group 2 showed significantly higher age, blood pressure, AVC, and MVC and significantly lower hemoglobin, sclerostin, and Dkk-1 levels. LVM and LVMI had a significant linear negative correlation to both serum sclerostin and Dkk-1 (r = -0.329 and -0.257, P=0.01 and 0.046 for LVM; r = -0.427 and -0.324, P=0.001 and 0.012 for LVMI, resp.). Serum Dkk-1 was an independent negative indicator for LVM and LVMI in multiple regression analyses (P=0.003 and 0.041 with 95% CI = -0.963 to -0.204 and -0.478 to -0.010, resp.).

CONCLUSION

Serum sclerostin and Dkk-1 were significantly lower in HD patients with increased LVMI > 125 gm/m2, and both had a significant linear negative correlation with LVM and LVMI. Dkk-1 was a significant negative independent indicator for LVM and LVMI in HD patients.

Meta-analysis of the association between sclerostin level and adverse clinical outcomes in patients undergoing maintenance haemodialysis

BACKGROUND

Studies regarding the relationship of sclerostin (Scl) with clinical outcomes in patients undergoing maintenance haemodialysis have yielded controversial findings. This meta-analysis was performed to investigate the predictive role of Scl in this patient population.

METHODS

Several electronic medical databases (e.g. PubMed, Embase, Web of Science and Cochrane Library) were searched for eligible studies through December 20, 2019. Summary hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated based on Scr level (high or low) using a random or fixed effects model.

RESULTS

From among 641 initially screened publications, 16 eligible studies were included in this meta-analysis. A high Scl level was not associated with cardiovascular events [HR = 0.8 (95% CI, 0.42-1.35)] or all-cause mortality [HR = 0.93 (95% CI, 0.56-1.54)]. There was high heterogeneity, but no evidence of publication bias. Interestingly, a high Scl level was associated with reduced cardiovascular events [HR = 0.44 (95% CI, 0.29-0.69)] in the subgroup by shorter follow-up period or all-cause mortality [pooled HR = 0.58 (95% CI, 0.36-0.91)] by shorter dialysis vintage.

CONCLUSION

This meta-analysis indicated that a high Scl level did not predict total clinical outcomes in patients undergoing maintenance haemodialysis despite survival benefits in the subgroups. The predictive role of Scl in these patients should be further evaluated in large prospective studies.

Diagnostic value of phosphatidylethanolamine binding protein 4 levels in patients receiving nursing interventions for advanced chronic kidney disease

OBJECTIVE

To explore the diagnostic role of phosphatidylethanolamine binding protein 4 (PEBP4) in patients with chronic kidney disease (CKD) receiving nursing interventions.

METHODS

ELISA was used to evaluate serum PEBP4 levels. Receiver-operating characteristic curve analysis was used to assess diagnostic accuracy. Spearman correlation analysis was used to assess the relationships between PEBP4 levels and biochemical indexes.

RESULTS

Serum PEBP4 was high in CKD patients compared with healthy individuals. PEBP4 levels were positively correlated with pathological stage in CKD patients. PEBP4 had higher sensitivity for diagnosis of CKD than common indexes including blood urea nitrogen, creatinine and C-reactive protein. Among CKD patients treated with calcium channel blockers, serum PEBP4 levels declined notably and were associated with concentrations of K+, Na+, Cl- and Ca2+. Nursing interventions significantly decreased serum PEBP4 levels. A significant association between serum PEBP4 level and ionic concentration was observed in CKD patients receiving nursing interventions.

CONCLUSIONS

This prospective study demonstrated that PEBP4 level might represent an effective diagnostic biomarker in CKD patients. PEBP4 also acted as a valuable care compliance factor for determining the necessity for nursing interventions. Nursing interventions restored ion channel function and subsequently resulted in decreased PEBP4 levels and proteinuria.

The Role of Sclerostin in Bone and Ectopic Calcification

Sclerostin, a 22-kDa glycoprotein that is mainly secreted by the osteocytes, is a soluble inhibitor of canonical Wnt signaling. Therefore, when present at increased concentrations, it leads to an increased bone resorption and decreased bone formation. Serum sclerostin levels are known to be increased in the elderly and in patients with chronic kidney disease. In these patient populations, there is a high incidence of ectopic cardiovascular calcification. These calcifications are strongly associated with cardiovascular morbidity and mortality. Although data are still controversial, it is likely that there is a link between ectopic calcification and serum sclerostin levels. The main question, however, remains whether sclerostin exerts either a protective or deleterious role in the ectopic calcification process.

Should We Consider the Cardiovascular System While Evaluating CKD-MBD?

Cardiovascular (CV) disease is highly prevalent in the population with chronic kidney disease (CKD), where the risk of CV death in early stages far exceeds the risk of progression to dialysis. The presence of chronic kidney disease-mineral and bone disorder (CKD-MBD) has shown a strong correlation with CV events and mortality. As a non-atheromatous process, it could be partially explained why standard CV disease-modifying drugs do not provide such an impact on CV mortality in CKD as observed in the general population. We summarize the potential association of CV comorbidities with the older (parathyroid hormone, phosphate) and newer (FGF23, Klotho, sclerostin) CKD-MBD biomarkers.

Sclerostin: a new biomarker of CKD-MBD

The causes of the increased cardiovascular risk associated with kidney diseases partly reside in the chronic kidney disease-mineral bone disorder (CKD-MBD) syndrome. Three cardiovascular risk factors [hyperphosphatemia, vascular calcification, and elevated fibroblast growth factor 23 (FGF23)] levels have been discovered within the CKD-MBD over the last decades. In addition, sclerostin is recently presented as a new bone and vascular disease biomarker. This 22-kDa glycoprotein, secreted mainly by osteocytes, is a soluble inhibitor of the canonical Wnt pathway that has a pivotal role in bone biology and turnover. CKD patients are reported with higher levels of sclerostin, and levels decrease during dialysis. Sclerostin is associated with vascular calcification and CV risk in CKD, although data are still controversial. The question whether serum sclerostin has protective or deleterious role in CKD-MBD pathophysiology, and therefore in cardiovascular risk and overall mortality, is still open and needs to be answered. The standardization of assays and the establishment of a clear cut-off values when sclerostin starts to switch from physiological to pathophysiological role have to be another important step. Further research is needed also to define its relationship with other CKD-MBD biomarkers for future diagnostic and therapeutic strategies.