VItamin K In PEritonial DIAlysis (VIKIPEDIA): Rationale and study protocol for a randomized controlled trial

Area of Science:

• Cardiovascular Medicine
• Nephrology
• Nutritional Science

Background:

• Vascular calcification (VC) is an active process driven by an imbalance favoring calcification promoters over inhibitors.
• Matrix Gla Protein (MGP), a potent VC inhibitor, requires vitamin K for activation; vitamin K depletion increases inactive dp-ucMGP, linked to VC and cardiovascular (CV) outcomes.
• End-stage renal disease (ESRD) patients exhibit elevated dp-ucMGP and accelerated VC.

Purpose of the Study:

• To evaluate the effect of vitamin K2 supplementation on arterial stiffness and CV events in ESRD patients on peritoneal dialysis (PD).
• To assess changes in pulse-wave velocity (PWV) as the primary endpoint.
• To investigate secondary endpoints including CV events, mortality, PD adequacy, blood pressure, and mineral metabolism.

Main Methods:

• Prospective, randomized, open-label, placebo-controlled trial (VIKIPEDIA) involving 44 PD patients.
• Baseline assessment of dp-ucMGP and PWV.
• Randomization (1:1) to receive vitamin K2 (1000 μg MK-7/day) or placebo for 1.5 years.

Main Results:

• Primary endpoint: Change in PWV between the vitamin K2 treatment group and the placebo group.
• Secondary endpoints: Occurrence of CV events, mortality, changes in PD adequacy, ambulatory blood pressure, and calcium/phosphorus/parathormone metabolism.
• Study registration: ClinicalTrials.gov (NCT04900610).

Conclusions:

• The VIKIPEDIA trial aims to determine if vitamin K2 supplementation can mitigate vascular calcification and cardiovascular disease in PD patients.
• Findings will elucidate vitamin K2's role in managing arterial stiffness and mineral metabolism in this high-risk population.
• This study will provide crucial data on vitamin K2's efficacy in improving cardiovascular outcomes for ESRD patients on PD.