High Dephosphorylated-Uncarboxylated MGP in Hemodialysis patients: risk factors and response to vitamin K2, A pre-post intervention clinical trail. (Aoun et al.)
Vascular calcifications are highly prevalent in hemodialysis patients. Dephosphorylated-uncarboxylated MGP (dpucMGP) was found to increase in vitamin K-deficient patients and may be associated with vascular calcifications. A new study, published in BMC Nephrology, of hemodialysis patients examined the risk factors and response to Vitamin K2 supplementation, and confirmed this population’s specific need to correct Vitamin K2 deficiency.
According to the researchers, the scientific data showed that the vitamin K2 intake in hemodialysis patients is estimated to be 40 percent lower than in the healthy individual group. It has been accepted by the European medical society that hemodialysis patients are vitamin K deficient, and they can benefit from vitamin K2 supplementation. However, this aspect had not yet been evaluated in Eastern Mediterranean populations.
The study, based in Lebanon, assessed if there is a correlation between vitamin K status and vascular calcification score in hemodialysis patients, and if K2 supplementation would improve extra-hepatic vitamin K status in this Eastern Mediterranean populations.
This is a prospective, pre-post intervention clinical trial involving 50 hemodialysis patients who received daily 360 μg of vitamin K2 as menaquinone-7 (MK-7) for 4 weeks. At baseline they were assessed for plasma dpucMGP levels and vascular calcification scores (AC24) as well as for other demographic, clinical and biological variables. DpucMGP levels were measured a second time at 4 weeks.
At baseline, dpucMGP levels were extremely elevated with a median of 3179.15 (1825.25; 4339.50) pM and correlated significantly with AC24 (Spearman’s rho = 0.43, P = 0.002). Using a bivariate regression analysis, the association between dpucMGP levels and AC24 was most significant when comparing dpucMGP levels less than 1000 to those more than 1000 pM (P = 0.02). DpucMGP levels higher than 5000 pM were significantly associated with females, patients with recent fracture and patients with lower serum albumin (respectively P = 0.02, 0.004 and 0.046). The average drop of dpucMGP at 4 weeks of treatment was found to be 86% with diabetics having the lowest drop rate (P = 0.01).
The main conclusion was that hemodialysis patients have profound vitamin K deficiency as assessed by high dp-ucMGP plasma levels. High dpucMGP level was significantly correlated with high aortic calcification scores and thus can be used as a non-invasive marker for vascular calcifications.
According to the researchers, “The daily administration of 360 μg of vitamin K2 (MK-7) decreased dpucMGP by 86 percent after 4 weeks and it was well tolerated. Further studies should be conducted to assess the change in vascular calcifications after an extended duration of therapy.”
Reference:
Aoun M et al. High Dephosphorylated-Uncarboxylated MGP in Hemodialysis patients: risk factors and response to vitamin K2, a pre-post intervention clinical trial. BMC Nephrol. 2017 Jun 7;18(1):191. doi: 10.1186/s12882-017-0609-3.