Abstract
Background/Objectives: Post-menopausal women are at an increased risk of developing cardiovascular disease. Menaquinone-7 (MK-7) is a fat-soluble vitamin involved in coagulation and maintaining vascular health. The aim of the post hoc analysis of this one-year study is to investigate the effects of MK-7 supplementation on the vascular parameters in pre-, peri-, and post-menopausal women. Methods: In a clinical intervention trial (NCT02404519), a total of 165 women with a low vitamin K status received either 180 µg of MK-7 daily (n = 82) or a matching placebo (n = 83) for one year. Established vascular parameters were measured before and after one year of vitamin K2 supplementation. Pre-, peri-, and post-menopausal women were subdivided according to arterial stiffness, with a high b-stiffness index defined as being greater than the overall median of 9.83. Results: The post hoc analyses showed a significant decrease in desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) plasma levels after MK-7 supplementation (pre/peri, p = 0.009; post, p < 0.001). MK-7 treatment significantly attenuated vascular stiffness in post-menopausal women (placebo +49.1% ± 77.4; MK-7 +9.4% ± 67.1; p = 0.035). Post-menopausal women with a high stiffness index showed significantly improved vascular markers after MK-7 treatment, e.g., a decreased blood pressure at brachialis (-3.0% ± 9.0; p = 0.007) and an increased distensibility coefficient (+13.3% ± 32.3; p = 0.040). Conclusions: Our results confirm that menopause affects vascular health status. Post-menopausal women with an increased stiffness benefit most from MK-7 supplementation, with a significantly improved blood pressure. Further research is needed to unravel the beneficial effects of MK-7 in post-menopausal women.