Phylloquinone Concentrations and the Risk of Vascular Calcification in Healthy Women

Objective—To investigate the association of plasma phylloquinone concentrations with coronary artery calcification (CAC) and vascular calcification.

Approach and results—In a prospective cohort of 508 postmenopausal women, plasma phylloquinone concentrations were measured by high-pressure liquid chromatography. Calcification was measured in the coronary arteries, aortic valve, mitral valve, and thoracic aorta by multidetector computed tomography. To combine these calcification scores, we dichotomized each of the 4 areas into present or absent. Because of the continuous measurement of CAC, we categorized this as calcification present if Agatston score was >0, and calcification score was calculated as the sum of the calcified areas. Multivariate-adjusted prevalence ratios and odds ratios were estimated using Poisson regression and multinomial logistic regression. After 8.5 years of follow-up, 22% of the women had no calcification, whereas 5% had calcification in all measured areas. Detectable phylloquinone concentrations were associated with increased CAC compared with nondetectable phylloquinone concentrations with a prevalence ratio of 1.34 (95% confidence interval, 1.01–1.77). When dividing women with detectable phylloquinone concentrations into low detectable (>0–0.70 nmol/L) and moderate to high detectable (>0.70 nmol/L) phylloquinone concentrations versus nondetectable phylloquinone concentrations, both were associated with increased CAC with a prevalence ratio of 1.32 (95% confidence interval, 0.99–1.76) and 1.36 (95% confidence interval, 1.02–1.81), respectively. Detectable phylloquinone concentrations were not associated with the number of calcified areas with an odds ratio_{(no versus ≥3 areas calcifications)} of 1.60 (95% confidence interval, 0.65–3.99; P=0.31).

Conclusions—Detectable phylloquinone concentrations are not associated with reduced vascular calcification but seemed to be associated with an increased prevalence of CAC.