Osteocalcin and Abdominal Aortic Calcification in Hemodialysis Patients: An Observational Cross-Sectional Study

Abstract

ObjectivesTo investigate the serum level of osteocalcin (OC), also known as bone Gla protein, in maintenance hemodialysis (MHD) patients and its correlation with abdominal aortic calcification (AAC).MethodsFrom July 2017 to February 2020, we enrolled 108 adult MHD patients. Routine fasting blood laboratory tests were performed before the start of the second hemodialysis in a week. Abdominal aortic calcification score (AACs) was assessed within 1 month. Pearson correlation and Logistic regression were used to analyze the data.ResultsThe OC level was 231.56 (25.92,361.33) ng/ml, elevating significantly in this group of MHD patients. It had a positive correlation with serum phosphorus (r = 0.511, P = 0.001), intact parathyroid hormone(iPTH) (r = 0.594, P = 0.0001), fibroblast growth factor 23(FGF23) (r = 0.485, P = 0.003) and a negative correlation with age(r = -0.356, P = 0.039). Based on the AACs, patients were divided into two groups. Serum OC level were higher in patients with AACs≥5 (p=0.032). A multiple logistics regression analysis revealed that age (odds ratio [OR]1.14, P=0.005) and OC(OR=1.10, P=0.008)were risk factors for high AACs(≥5).ConclusionThe study implicated that OC elevated significantly in this group of MHD patients.OC is positively correlated with phosphorus, iPTH, FGF23, and a negative correlation with age. OC was a risk factor for vascular calcification in this study, but this study did not classify osteocalcin as c-OC and unOC. Whether unOC is associated more directly with vascular calcification requires further study.

Association between Methylmalonic Acid and Abdominal Aortic Calcification in Adults: A Cross-Sectional Study

“…Serum MMA levels ≥250 nmol/L were found to substantially correlate with AAC, a severe vascular illness that frequently occurs with insulin resistance, diminished osteocalcin, diminished bone mineral density, and cardiovascular disease [25][26][27]. MMA is a biomarker of metabolic product accumulation associated with aging, and may trigger cancer progression and infiltration via metabolic reprograming [28].…”

Recognized and Potentially New Biomarkers—Their Role in Diagnosis and Prognosis of Cardiovascular Disease

“…However, in this study, OC was not classified as cOC and unOC. Whether unOC is more directly related to vascular calcification requires further research [ 129 ]. Compared to healthy subjects, HD patients presented significantly reduced serum levels of c-OC and increased serum levels of unOC [ 129 ].…”

“…Whether unOC is more directly related to vascular calcification requires further research [ 129 ]. Compared to healthy subjects, HD patients presented significantly reduced serum levels of c-OC and increased serum levels of unOC [ 129 ]. In another study that enrolled HD patients ( n = 189) and pre-dialysis CKD patients ( n = 89), the serum ucOC/intact OC ratio > 1.0 was observed in about 71.4% of HD patients, especially those with high bone turnover [ 130 ] Another study by Lin et al [ 131 ] revealed that higher serum OC level was associated with lower vascular reactivity index (VRI) and poorer endothelial dysfunction among kidney transplant recipients [ 131 , 132 ].…”

“…Second, difficulties arose in measuring ucOC and cOC, as there are few tests. It is unclear which test system provides the most accurate measurements due to comparability and heterogeneity issues for OC [ 129 ]. It should be noted that some studies have highlighted the observed differences between the various ethnic groups [ 135 ].…”

“…Osteocalcin and abdominal aortic calcification in hemodialysis patients: an observational cross-sectional study [129] OC OC proved to be a risk factor for vascular calcification, but further research is required to determine if ucOC is directly related to vascular calcification.…”