Sticht Center on Aging, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
J Nutr. 2011 Aug;141(8):1529-34. doi: 10.3945/jn.111.139634. Epub 2011 May 31.
Matrix Gla protein (MGP) is a calcification inhibitor in vascular tissue that must be carboxylated by vitamin K to function. Evidence suggests circulating uncarboxylated MGP (ucMGP) is elevated in persons with disease characterized by vascular calcification. The primary purpose of this study was to determine cross-sectional and longitudinal associations between plasma ucMGP, vitamin K status, and coronary artery calcium (CAC) in older adults without coronary heart disease. Genetic determinants of ucMGP were also explored. Cross-sectional associations among baseline plasma ucMGP, vitamin K status biomarkers [plasma phylloquinone, uncarboxylated prothrombin (PIVKA-II), serum uncarboxylated osteocalcin (%ucOC)], CAC, and plausible genetic polymorphisms were examined in 438 community-dwelling adults (60-80 y, 59% women). The effect of phylloquinone supplementation (500 μg/d) for 3 y on plasma ucMGP was determined among 374 participants. At baseline, plasma phylloquinone was lower and %ucOC and PIVKA-II were greater across higher plasma ucMGP quartiles (all P < 0.001, age-adjusted). Major allele homozygotes for MGP rs1800801 and rs4236 had higher plasma ucMGP than heterozygotes or minor allele homozygotes. (P ≤ 0.004). The decrease in plasma ucMGP was greater in the 190 participants who received phylloquinone (mean ± SD) (-345 ± 251 pmol/L) than in the 184 who did not (-40 ± 196 pmol/L) (P < 0.0001). CAC did not differ according to ucMGP quartile (P = 0.35, age-adjusted). In the phylloquinone-supplemented group, the 3-y change in ucMGP was not associated with the 3-y change in CAC [unstandard β (SE) = -0.02 (0.02); P = 0.44]. Plasma ucMGP was associated with vitamin K status biomarkers and was reduced following phylloquinone supplementation, suggesting it may be a useful marker of vitamin K status in vascular tissue. Plasma ucMGP did not reflect CAC in healthy older adults.
基质 Gla 蛋白（MGP）是血管组织中的一种钙化抑制剂，必须通过维生素 K 羧化才能发挥作用。有证据表明，患有血管钙化特征性疾病的人体内未羧化的 MGP（ucMGP）水平升高。本研究的主要目的是确定无冠心病的老年人血浆 ucMGP、维生素 K 状态与冠状动脉钙（CAC）之间的横断面和纵向关联。还探讨了 ucMGP 的遗传决定因素。在 438 名社区居住的成年人（60-80 岁，59%为女性）中，检查了基线时血浆 ucMGP、维生素 K 状态生物标志物[血浆叶绿醌、未羧化凝血酶原（PIVKA-II）、血清未羧化骨钙素（%ucOC）]、CAC 和合理的遗传多态性之间的横断面关联。在 374 名参与者中，还确定了补充叶绿醌（500μg/d）3 年对血浆 ucMGP 的影响。在基线时，血浆叶绿醌较低，较高血浆 ucMGP 四分位组的%ucOC 和 PIVKA-II 较高（均 P <0.001，年龄调整）。MGP rs1800801 和 rs4236 的主要等位基因纯合子比杂合子或次要等位基因纯合子的血浆 ucMGP 更高。（P≤0.004）。在接受叶绿醌治疗的 190 名参与者中，血浆 ucMGP 的下降幅度大于未接受治疗的 184 名参与者（-345±251 pmol/L）（-40±196 pmol/L）（P<0.0001）。根据 ucMGP 四分位组，CAC 无差异（P=0.35，年龄调整）。在补充叶绿醌的组中，ucMGP 的 3 年变化与 CAC 的 3 年变化无关[未标准化β（SE）=-0.02（0.02）；P=0.44]。血浆 ucMGP 与维生素 K 状态生物标志物相关，并且在叶绿醌补充后降低，这表明它可能是血管组织中维生素 K 状态的有用标志物。在健康的老年人中，血浆 ucMGP 并未反映 CAC。
