Background

There are conflicting reports on the association of undercarboxylated osteocalcin (ucOC) in cardiovascular disease development, including endothelial function and hypertension. We tested whether ucOC is related to blood pressure and endothelial function in older adults, and if ucOC directly affects endothelial-mediated vasodilation in the carotid artery of rabbits.

Methods

In older adults, ucOC, blood pressure, pulse wave velocity (PWV) and brachial artery flow-mediated dilation (BAFMD) were measured (n = 38, 26 post-menopausal women and 12 men, mean age 73 ± 0.96). The vasoactivity of the carotid artery was assessed in male New Zealand White rabbits following a four-week normal or atherogenic diet using perfusion myography. An ucOC dose response curve (0.3–45 ng/ml) was generated following incubation of the arteries for 2-hours in either normal or high glucose conditions.

Results

ucOC levels were higher in normotensive older adults compared to those with stage 2 hypertension (p < 0.05), particularly in women (p < 0.01). In all participants, higher ucOC was associated with lower PWV (p < 0.05), but not BAFMD (p > 0.05). In rabbits, ucOC at any dose did not alter vasoactivity of the carotid artery, either following a normal or an atherogenic diet (p > 0.05).

Conclusion

Increased ucOC is associated with lower blood pressure and increased arterial stiffness, particularly in post-menopausal women. However, ucOC administration has no direct short-term effect on endothelial function in rabbit arteries. Future studies should explore whether treatment with ucOC, in vivo, has direct or indirect effects on blood vessel function.

中文翻译：

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羧化骨钙素不足与女性老年人血管功能有关，但不影响雄性兔颈动脉离体的血管功能

背景

关于羧化骨钙蛋白（ucOC）不足与心血管疾病发展（包括内皮功能和高血压）的关系的报道相互矛盾。我们测试了ucOC是否与老年人的血压和内皮功能有关，以及ucOC是否直接影响兔颈动脉中内皮介导的血管舒张。

方法

在老年人中，测量了ucOC，血压，脉搏波速度（PWV）和肱动脉血流介导的扩张（BAFMD）（n = 38，绝经后妇女26例，男性12例，平均年龄73±0.96）。在四周正常饮食或动脉粥样硬化饮食后，使用灌注肌电图评估雄性新西兰白兔的颈动脉血管活性。在正常或高葡萄糖条件下将动脉孵育2小时后，会产生ucOC剂量反应曲线（0.3–45 ng / ml）。

结果

与患有2期高血压的人相比，血压正常的老年人中的ucOC水平更高（p <0.05），尤其是女性（p <0.01）。在所有参与者中，较高的ucOC与较低的PWV相关（p <0.05），而与BAFMD没有相关性（p> 0.05）。在正常饮食或致动脉粥样硬化饮食中，兔子的任何剂量的ucOC都不会改变颈动脉的血管活性（p> 0.05）。

结论

ucOC增加与血压降低和动脉僵硬度增加有关，尤其是在绝经后妇女中。但是，施用ucOC对兔动脉内皮功能没有直接的短期影响。未来的研究应探讨在体内用ucOC进行治疗是否对血管功能有直接或间接影响。