Beneficial effects of one-year menaquinone-7 supplementation on vascular stiffness and blood pressure in post-menopausal women

Abstract Background Cardiovascular disease (CVD) is responsible for 35% of total deaths worldwide. Sex hormones, such as oestrogen and progesterone, have a cardiovascular protective role in women. After menopause, women are more prone to hypertension and vascular stiffness, accelerated vascular aging and risk for CVD. Menaquinone-7 (MK-7) is a fat-soluble vitamin K2 and serves as cofactor for vitamin K-dependent protein carboxylation. The vitamin K-dependent matrix Gla protein (MGP) is synthesized in the vasculature and has shown to inhibit vascular calcification and stiffness. Purpose To investigate effects of MK-7 on vascular stiffness in pre/peri- versus post-menopausal women. Methods In a double-blind placebo-controlled clinical intervention trial (NCT02404519), 166 women (age 40-70; dephosphorylated-undercarboxylated MGP (dp-ucMGP) > 400 pmol/L at baseline) received daily 180 µg of MK-7 (n=83) or a matching placebo (n=83) for one year. Blood was sampled during intake (inclusion/exclusion), at baseline and at the end of the study to determine dp-ucMGP levels. Regional carotid-femoral (cf-PWV) and carotid-radial (cr-PWV) pulse wave velocities, vessel wall characteristics (e.g., intima-media thickness, arterial diameter, and local carotid artery PWV (caPWV), and arterial blood pressure were measured at baseline and after one year of vitamin K2 supplementation. Pre/peri- and post-menopausal women were sub-divided according to arterial stiffness (high b-stiffness index: > overall median 9.83). Results Post-hoc analyses showed a significant decrease in dp-ucMGP plasma levels of MK-7 supplemented pre/peri-menopausal (n=34; -8.58% ± 27.65; p=0.009) and post-menopausal women (n=48; -13.40% ± 27.45; p