非裔美国血液透析患者的无活性基质 Gla 蛋白、动脉僵硬度和内皮功能。

Inactive Matrix Gla Protein, Arterial Stiffness, and Endothelial Function in African American Hemodialysis Patients.

机构信息

Georgia Prevention Institute, Department of Population Health Sciences, Medical College of Georgia, Augusta University, Augusta, Georgia, USA.

Department of Pediatrics, Medical College of Georgia, Augusta University, Augusta, Georgia, USA.

出版信息

Am J Hypertens. 2018 May 7;31(6):735-741. doi: 10.1093/ajh/hpy049.

DOI:10.1093/ajh/hpy049

PMID:29635270

Abstract

BACKGROUND

Matrix Gla protein (MGP) is a vascular calcification inhibitor dependent upon vitamin K for activation. Evidence suggests that elevated plasma inactive MGP levels (desphospho-uncarboxylated MGP, dp-ucMGP; indicating poorer vascular vitamin K status) are associated with greater cardiovascular disease (CVD) risk. Despite African Americans experiencing highest rates of kidney failure and CVD events, relationships between dp-ucMGP and CVD risk markers have not been examined in this population. We investigated vascular vitamin K status (via plasma dp-ucMGP) between African American hemodialysis (HD) patients and healthy controls, and the associations of dp-ucMGP with arterial stiffness and endothelial function in HD patients only.

METHODS

In 37 African American HD patients and 37 age- and race-matched controls, plasma dp-ucMGP was measured by enzyme immunoassay as a marker of vascular vitamin K status. Carotid-femoral pulse wave velocity (PWV; arterial stiffness measurement) and brachial artery flow-mediated dilation (FMD; endothelial function measurement) were assessed by applanation tonometry and ultrasound, respectively, in HD patients only.

RESULTS

Mean dp-ucMGP levels were 5.6 times higher in HD patients vs. controls (2,139 ± 1,102 vs. 382 ± 181 pmol/l, P < 0.01). Multiple linear regression, adjusting for age, sex, dialysis vintage, diabetes mellitus, CVD history, body mass index, and blood pressure, revealed that dp-ucMGP was independently related to PWV (standardized β = 0.49) and FMD (standardized β = -0.53) (both P < 0.01).

CONCLUSIONS

Our data suggest that the higher plasma dp-ucMGP concentrations found in African American HD patients may be associated with greater arterial stiffness and endothelial dysfunction.

摘要

背景

基质 Gla 蛋白（MGP）是一种血管钙化抑制剂，其活性依赖于维生素 K。有证据表明，血浆中无活性 MGP 水平升高（脱磷酸非羧化 MGP，dp-ucMGP；表明血管维生素 K 状态较差）与心血管疾病（CVD）风险增加相关。尽管非裔美国人患肾衰竭和 CVD 事件的比率最高，但 dp-ucMGP 与 CVD 风险标志物之间的关系尚未在该人群中进行研究。我们研究了非裔美国血液透析（HD）患者和健康对照组之间的血管维生素 K 状态（通过血浆 dp-ucMGP 测量），以及仅在 HD 患者中 dp-ucMGP 与动脉僵硬和内皮功能的相关性。

方法

在 37 名非裔美国 HD 患者和 37 名年龄和种族匹配的对照组中，通过酶免疫测定法测量血浆 dp-ucMGP 作为血管维生素 K 状态的标志物。仅在 HD 患者中，通过平板张力测量法评估颈动脉-股动脉脉搏波速度（PWV；动脉僵硬测量）和肱动脉血流介导的扩张（FMD；内皮功能测量）。

结果

HD 患者的平均 dp-ucMGP 水平比对照组高 5.6 倍（2139 ± 1102 比 382 ± 181 pmol/l，P < 0.01）。多元线性回归，调整年龄、性别、透析龄、糖尿病、CVD 病史、体重指数和血压，显示 dp-ucMGP 与 PWV（标准化β=0.49）和 FMD（标准化β=-0.53）独立相关（均 P < 0.01）。