Effect of vitamin K2 on progression of atherosclerosis and vascular calcification in nondialyzed patients with chronic kidney disease stages 3-5

INTRODUCTION Observational studies have shown that high dietary intake of vitamin K-2 is associated with reduced risk of coronary vascular disease and vascular calcification. OBJECTIVES We assessed the effect of vitamin K-2 substitution on the progression of atherosclerosis and calcification in nondialyzed patients with CKD stages 3-5. PATIENTS AND METHODS The study included 42 nondialyzed patients with CKD. The following measurements were taken at baseline and after 270 +/- 12 days of supplementation with vitamin K-2 at a dose of 90 mu g (menaquinone, MK-7) together with 10 mu g of cholecalciferol (K+D group) or 10 mu g of cholecalciferol (group D): common carotid intima-media thickness (CCA-IMT), coronary artery calcification score (CACS), basic biochemical parameters, lipids, and calcification modulators: matrix Gla protein (MGP), desphosphorylated-uncarboxylated MGP (dp-ucMGP), osteoprotegerin (OPG), fetuin A, osteocalcin (OC), and fibroblast growth factor 23. RESULTS The increase of CCA-IMT was significantly lower in the K+D group compared with the D group: from 0.95 +/- 0.2 mm to 1.01 +/- 0.3, P = 0.003 vs from 1.02 +/- 0.2 mm to 1.16 +/- 0.3, P = 0.003 (Delta CCA-IMT, 0.06 +/- 0.08 vs 0.136 +/- 0.05 mm, P = 0.005, respectively). The increase in CACS was slightly lower in the K+D group than in the D group (Delta CACS, 58.1 +/- 106.5 AU vs 74.4 +/- 127.1 AU, P = 0.7). In the K+D group, a significant decrease in the level of dp-ucMGP and total OC was observed. CONCLUSIONS A 270-day course of vitamin K-2 administration in patients with CKD stages 3-5 may reduce the progression of atherosclerosis, but does not significantly affect the progression of calcification. Vitamin K-2 significantly changes the levels of calcification promoters and inhibitors: dp-ucMGP, OC, and OPG.