Effect of Vitamin K2 Supplementation on Vascular Calcification in Hemodialysis Patients: a Controlled Randomized Trial.

This study is designed according to the ethical reference framework for biomedical research of the Declaration of Helsinki. Its design is prospective, randomized, double blind. Study subjects will be assigned either Arm 1 or control (vial with 1000 μL of saline) or Arm 2 or treated group (vial with 1000 μL containing 2000 μg of Vitamin K2). The trial protocol was approved by the ethics committee of the Catholic University of Salta and written informed consent will be made available to all patients who agree to participate and meet the inclusion criteria. Vascular calcification will be evaluated at the beginning of the study to determine the presence of vascular calcification and at the end of the study to assess changes, if any. The carotid artery examination will be performed with a GE VIVID 5 (GE Healthcare, Little Chalfont, Buckinghamshire, UK) with a 7.5 MHz linear probe. The protocol used to obtain images is consistent with the recommendations of the American Society of Echocardiography. Longitudinal images will be obtained by means of B-mode ultrasound, the maximum and the global median intima thickness (EIM) value of the common carotid artery and the presence of carotid plaques (defined as isolated and focal areas of the abnormal intima that protrude into the lumen more than 1.5 mm or at least 50% of the surrounding total mean intimate value). The EIM represents the thickness of the intima, plus the component of the mean of the vessel wall; with an automated computerized system of the equipment, on the distal wall of both common carotid arteries, 1 cm below the carotid bulb, along a 10 mm long straight arterial segment. Patients may be stratified into 3 groups according to the EIM value: EIM patients with <0.5 mm are considered disease-free; patients with IMD between 0.6-1 mm will be considered to be non-significantly affected by the disease; patients with IMD> 1 mm will be grouped as affected by significant disease (Table 1). Therefore, carotid atherosclerosis is considered in the presence of plaques or an EIM> 1 mm. 2.5.3 Table 1. Thickness of the intima plus the component of the mean in the wall of a vessel associated or not with the presence of vascular calcification.

EIM VALUE Presence or not of vascular calcification <0,5 mm Patients without vascular calcification 0,6-1 mm Patients non-significantly affected by the disease > 1 mm Patients significantly affected by the disease