Vitamin K dependent protection of renal function in multi-ethnic population studies (Wei et al.)
The vitamin K-dependent matrix Gla- protein (MGP) plays an important role in in modulating vascular calcium metabolism. MGP is a local natural calcification inhibitor, which requires vitamin K to be activated. Inactive MGP, known as desphospho-uncarboxylated MGP (dp-uc MGP), behaves as a circulating biomarker associated with cardiovascular risk, more severe vascular illness, and higher mortality. Total uncarboxylated MGP (t-ucMGP) is not a marker of vitamin K status, but reflects arterial calcification.
The role of MGP in preserving renal function was tested in a recently published study by Wei et al. The researchers tested their hypothesis in white people enrolled in the FLEMENGHO study and sought replication in the white and black participants enrolled in the South African Study regarding the influence of sex, age, and ethnicity on insulin sensitivity and cardiovascular function (SAfrEIC). In 1166 white Flemish and 714 South Africans, estimated glomerular filtration (eGFR) and stage of chronic kidney disease (CKD) with inactive dp-ucMGP were correlated.
The results indicated that in the general population, eGFR decreases and CKD risk increases with higher dp-ucMGP, a marker of vitamin K deficiency. These epidemiological findings support the concept that active MGP might not only inhibit calcification in large arteries, but might also be protective for renal function. This study reveal the potential of vitamin K supplementation to promote renal health.
“It is important to point out that low dp-ucMGP reflects high intake of vitamin K, mostly vitamin K2,” says Dr. Katarzyna Maresz, president of the International Science and Health Foundation. “Moreover, vitamin K2 as MK-7 has been shown to decrease the level of dp-ucMGP after supplementation in other clinical studies.”
Further, Dr. Murray Epstein with the University of Miami Miller School of Medicine, published a commentary of the Wei paper entitled ‘Matrix Gla-Protein (MGP) Not Only Inhibits Calcification in Large Arteries But Also May Be Renoprotective: Connecting the Dots.’ Epstein concluded that the Wei study “serves to extend the protective role of vitamin K from macrocirculation to the microcirculation as exemplified by renal function, and possibly suggest a potential for prevention by vitamin K supplementation.”
Wei FF, Drummen NE, Schutte AE, Jacobs L, Petit T, Yang WY, et al. Vitamin K Dependent Protection of Renal Function in Multi-ethnic Population Studies. EBioMedicine. 2016 Jan 13;4:162-9. doi: 10.1016/j.ebiom.2016.01.011. eCollection 2016