Yoshida Makiko, Jacques Paul F, Meigs James B, Saltzman Edward, Shea M Kyla, Gundberg Caren, Dawson-Hughes Bess, Dallal Gerard, Booth Sarah L
Jean Mayer US Department of Agriculture, Human Nutrition Research Center, Tufts University, Boston, Massachusetts, USA.
Diabetes Care. 2008 Nov;31(11):2092-6. doi: 10.2337/dc08-1204. Epub 2008 Aug 12.
Vitamin K has a potentially beneficial role in insulin resistance, but evidence is limited in humans. We tested the hypothesis that vitamin K supplementation for 36 months will improve insulin resistance in older men and women.
This was an ancillary study of a 36-month, randomized, double-blind, controlled trial designed to assess the impact of supplementation with 500 microg/day phylloquinone on bone loss. Study participants were older nondiabetic men and women (n = 355; aged 60-80 years; 60% women). The primary outcome of this study was insulin resistance as measured by homeostasis model assessment (HOMA-IR) at 36 months. Fasting plasma insulin and glucose were examined as the secondary outcomes.
The effect of 36-month vitamin K supplementation on HOMA-IR differed by sex (sex x treatment interaction P = 0.02). HOMA-IR was statistically significantly lower at the 36-month visit among men in the supplement group versus the men in the control group (P = 0.01) after adjustment for baseline HOMA-IR, BMI, and body weight change. There were no statistically significant differences in outcome measures between intervention groups in women.
Vitamin K supplementation for 36 months at doses attainable in the diet may reduce progression of insulin resistance in older men.
维生素K在胰岛素抵抗方面可能具有有益作用，但人体研究证据有限。我们检验了以下假设：补充维生素K 36个月可改善老年男性和女性的胰岛素抵抗。
这是一项辅助研究，基于一项为期36个月的随机、双盲、对照试验，该试验旨在评估每日补充500微克叶绿醌对骨质流失的影响。研究参与者为年龄较大的非糖尿病男性和女性（n = 355；年龄60 - 80岁；60%为女性）。本研究的主要结局是36个月时通过稳态模型评估（HOMA-IR）测得的胰岛素抵抗。空腹血浆胰岛素和葡萄糖作为次要结局进行检测。
36个月维生素K补充对HOMA-IR的影响因性别而异（性别×治疗交互作用P = 0.02）。在调整基线HOMA-IR、体重指数（BMI）和体重变化后，补充组男性在36个月访视时的HOMA-IR显著低于对照组男性（P = 0.01）。干预组女性的结局指标之间无统计学显著差异。
以饮食中可达到的剂量补充维生素K 36个月可能会减缓老年男性胰岛素抵抗的进展。
