Department of Thrombosis and Haemostasis, Leiden University Medical Centre, Leiden, The Netherlands.
Br J Haematol. 2010 May;149(4):598-605. doi: 10.1111/j.1365-2141.2010.08108.x. Epub 2010 Feb 11.
It is unclear what advice should be given to patients using vitamin K antagonists with respect to dietary vitamin K intake. We performed a nested case-control study in patients attending a Dutch anticoagulation clinic, to determine the association between vitamin K intake and subtherapeutic International Normalized Ratio (INR) values and the interaction between usual and recent vitamin K intake. Compared to patients with a normal usual vitamin K intake, those with a high vitamin K intake had a decreased risk of a subtherapeutic INR [Hazard Ratio (HR) 0.80, 95% confidence interval (CI): 0.56-1.16] and patients with a low vitamin K intake an increased risk (HR 1.33, 95% CI: 0.79-2.25). In patients with a low usual vitamin K intake, recent vitamin K intake was twice as high in cases as in controls (164 vs. 85 microg/d). Such a difference was not observed in patients with a normal or high usual vitamin K intake. Our results suggest that a high vitamin K intake reduces the risk of a low INR by lessening the influence of incidental consumption of vitamin K rich food on the INR. These findings support the recommendation for patients on vitamin K antagonists to eat a sufficient amount of vitamin-K containing foods.
目前尚不清楚对于使用维生素 K 拮抗剂的患者，应该给予何种关于饮食中维生素 K 摄入量的建议。我们在荷兰抗凝门诊的患者中进行了一项巢式病例对照研究，以确定维生素 K 摄入量与治疗范围外国际标准化比值（INR）值之间的关系，以及通常的和近期的维生素 K 摄入量之间的相互作用。与通常维生素 K 摄入量正常的患者相比，高维生素 K 摄入量的患者治疗范围外 INR 值的风险降低[风险比（HR）0.80，95%置信区间（CI）：0.56-1.16]，而维生素 K 摄入量低的患者风险增加（HR 1.33，95% CI：0.79-2.25）。在通常维生素 K 摄入量低的患者中，病例组与对照组相比，近期维生素 K 摄入量高两倍（164 与 85 微克/天）。在通常维生素 K 摄入量正常或高的患者中未观察到这种差异。我们的研究结果表明，高维生素 K 摄入量通过减轻偶然摄入富含维生素 K 的食物对 INR 的影响，降低了低 INR 值的风险。这些发现支持了对于使用维生素 K 拮抗剂的患者的建议，即应摄入足够的含维生素 K 的食物。
