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ABSTRACT: Objective
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.Research design and methods
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.Results
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.Conclusions
Vitamin K supplementation for 36 months at doses attainable in the diet may reduce progression of insulin resistance in older men.
SUBMITTER: Yoshida M
PROVIDER: S-EPMC2571052 | biostudies-literature | 2008 Nov
REPOSITORIES: biostudies-literature
Yoshida Makiko M Jacques Paul F PF Meigs James B JB Saltzman Edward E Shea M Kyla MK Gundberg Caren C Dawson-Hughes Bess B Dallal Gerard G Booth Sarah L SL
Diabetes care 20080812 11
<h4>Objective</h4>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.<h4>Research design and methods</h4>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 nondia ...[more]