Phylloquinone intake, insulin sensitivity, and glycemic status in men and women.
BACKGROUND
Limited evidence suggests that vitamin K may have a beneficial role in glucose homeostasis. No observational data exist on the associations between vitamin K intake and insulin sensitivity.


OBJECTIVE
We aimed to examine associations between vitamin K intake and measures of insulin sensitivity and glycemic status in men and women aged 26-81 y.


METHODS
We assessed the cross-sectional associations of self-reported phylloquinone (vitamin K(1)) intake with insulin sensitivity and glycemic status in the Framingham Offspring Cohort. Dietary and supplemental phylloquinone intakes were assessed by using a food-frequency questionnaire. Insulin sensitivity was measured by fasting and 2-h post-oral-glucose-tolerance test (OGTT) insulin, the homeostasis model assessment of insulin resistance (HOMA-IR), and the insulin sensitivity index (ISI(0,120)). Glycemic status was assessed by fasting and 2-h post-OGTT glucose and glycated hemoglobin (HbA(1c)).


RESULTS
Higher phylloquinone intake was associated with greater insulin sensitivity and glycemic status, as measured by 2-h post-OGTT insulin and glucose and ISI(0,120), after adjustment for age, sex, waist circumference, lifestyle characteristics, and diet quality [2-h post-OGTT insulin: lowest and highest quintile, 81.0 and 72.7 microU/mL, respectively (P for trend = 0.003); 2-h post-OGTT glucose: 106.3 and 101.9 mg/dL, respectively (P for trend = 0.009); ISI(0,120): 26.3 and 27.3 mg L(2)/mmol mU min (P for trend = 0.009)]. Phylloquinone intake was not associated with fasting insulin and glucose concentrations, HOMA-IR, or HbA(1c).


CONCLUSIONS
Our findings support a potential beneficial role for phylloquinone in glucose homeostasis in men and women.
Yoshida
Makiko
M
Jean Mayer USDA Human Nutrition Research Center, Tufts University, Boston, MA 02111, USA.
Booth
Sarah L
SL
Meigs
James B
JB
Saltzman
Edward
E
Jacques
Paul F
PF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000517:prevention & control*; D004032:Diet; D019587:Dietary Supplements; D005215:Fasting; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena / Q000502:physiology; D016017:Odds Ratio; D011795:Surveys and Questionnaires; D010837:Vitamin K 1 / Q000008:administration & dosage*
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D010837:Vitamin K 1