Faculty of Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Department of Medical Education, National Taiwan University Hospital, Taipei, Taiwan.
Calcif Tissue Int. 2023 Oct;113(4):416-425. doi: 10.1007/s00223-023-01122-y. Epub 2023 Sep 4.
Vascular calcification, a component of chronic kidney disease-mineral and bone disorder (CKD-MBD), is prevalent in patients with end-stage kidney disease (ESKD) and contributes to high mortality. However, the association between the blood level of total osteocalcin (OC) and vascular calcification and mortality remains inconclusive. We, therefore, investigated whether different OC fractions can serve as biomarkers of vascular calcification and mortality in the ESKD population.
This observational cohort study enrolled patients on maintenance hemodialysis. Plasma carboxylated OC (cOC), uncarboxylated OC (ucOC), and intact parathyroid hormone (PTH) were measured. The percentage of carboxylated OC (%cOC) was calculated as dividing cOC by total OC. The vascular calcification severity was defined by an aortic calcification grade. The patients were followed for three years and one month.
A total of 184 patients were enrolled. In the multivariable logistic regression, plasma %cOC, but not cOC or ucOC, was independently associated with the severity of vascular calcification (OR 1.019, p = 0.036). A significant U-shaped correlation was found between plasma %cOC and PTH (p = 0.002). In the multivariable Cox regression, patients with higher plasma %cOC had a higher risk of mortality (quartiles Q4 versus Q1-Q3, HR 1.991 [95% CI: 1.036-3.824], p = 0.039).
In patients undergoing chronic hemodialysis, plasma %cOC positively correlated with vascular calcification and exhibited a U-shaped correlation with PTH. Furthermore, a higher plasma %cOC was associated with increased mortality. These findings suggest that plasma %cOC may serve as a biomarker for CKD-MBD and a predictor of clinical outcomes in chronic hemodialysis patients.
血管钙化是慢性肾脏病-矿物质和骨异常（CKD-MBD）的一个组成部分，在终末期肾病（ESKD）患者中很常见，并导致高死亡率。然而，总骨钙素（OC）的血液水平与血管钙化和死亡率之间的关系仍不确定。因此，我们研究了不同的 OC 分数是否可以作为 ESKD 人群中血管钙化和死亡率的生物标志物。
这项观察性队列研究纳入了维持性血液透析的患者。测量了血浆羧化 OC（cOC）、未羧化 OC（ucOC）和完整甲状旁腺激素（PTH）。计算 cOC 与总 OC 的比值作为羧化 OC 的百分比（%cOC）。血管钙化严重程度定义为主动脉钙化程度。对患者进行了三年零一个月的随访。
共纳入 184 例患者。在多变量逻辑回归中，血浆 %cOC 与血管钙化严重程度独立相关（OR 1.019，p=0.036），而 cOC 或 ucOC 则无此相关性。血浆 %cOC 与 PTH 之间存在显著的 U 型相关性（p=0.002）。在多变量 Cox 回归中，血浆 %cOC 较高的患者死亡风险更高（四分位 Q4 与 Q1-Q3，HR 1.991[95%CI：1.036-3.824]，p=0.039）。
在接受慢性血液透析的患者中，血浆 %cOC 与血管钙化呈正相关，与 PTH 呈 U 型相关。此外，较高的血浆 %cOC 与死亡率增加相关。这些发现表明，血浆 %cOC 可能作为 CKD-MBD 的生物标志物，并预测慢性血液透析患者的临床结局。
