Kurnatowska Ilona, Grzelak Piotr, Masajtis-Zagajewska Anna, Kaczmarska Magdalena, Stefańczyk Ludomir, Vermeer Cees, Maresz Katarzyna, Nowicki Michał
Department of Nephrology, Hypertension and Kidney Transplantation, Medical University of x0141;x00F3;dx017A;, Poland.
Kidney Blood Press Res. 2016;41(3):231-9. doi: 10.1159/000443426. Epub 2016 Apr 21.
BACKGROUND/AIMS: Desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) is formed as a result of vitamin K insufficiency. The aim of this study was to investigate the association between plasma dp-ucMGP, kidney function and cardiovascular risk factors before and after 9-months substitution of vitamin K2 in non-dialysis patients with chronic kidney disease (CKD) stage 4 and 5.
38 CKD patients were supplemented for 270±12 days with 90 µg vitamin K2 and 10 µg cholecalciferol or 10 µg cholecalciferol alone. At baseline and at follow-up circulating calcium, phosphate, lipids, hemoglobin, albumin and total protein, dp-ucMGP, osteoprotegerin, fetuin A, osteocalcin and fibroblast grown factor 23 (FGF-23) were assessed. Proteinuria was assessed in the first morning void.
Baseline plasma dp-ucMGP was 1018.6±498.3 pmol/l and was significantly higher in patients at stage 5 CKD (1388.3 ±505.4 pmol/l) than at stage 4 (885.1±419.7 pmol/l), p=0.04. Vitamin K2 supplementation resulted in a decrease of dp-ucMGP level by 10.7%. Plasma dp-ucMGP was positively associated with proteinuria, serum creatinine, PTH and FGF-23; and inversely associated with glomerular filtration rate, serum hemoglobin and albumin.
High dp-ucMGP level, reflecting a poor vitamin K status seems to be associated with kidney damage and may be also a marker of cardiovascular risk in CKD patients. Supplementation with vitamin K2 may improve the carboxylation status of MGP.
背景/目的：去磷酸化未羧化基质Gla蛋白（dp-ucMGP）是维生素K缺乏的产物。本研究旨在调查4期和5期慢性肾脏病（CKD）非透析患者在补充维生素K2 9个月前后，血浆dp-ucMGP、肾功能与心血管危险因素之间的关联。
38例CKD患者补充90μg维生素K2和10μg胆钙化醇或仅补充10μg胆钙化醇，为期270±12天。在基线和随访时评估循环钙、磷、脂质、血红蛋白、白蛋白和总蛋白、dp-ucMGP、骨保护素、胎球蛋白A、骨钙素和成纤维细胞生长因子23（FGF-23）。在晨尿中评估蛋白尿。
基线血浆dp-ucMGP为1018.6±498.3pmol/l，5期CKD患者（1388.3±505.4pmol/l）显著高于4期患者（885.1±419.7pmol/l），p=0.04。补充维生素K2使dp-ucMGP水平降低了10.7%。血浆dp-ucMGP与蛋白尿、血清肌酐、甲状旁腺激素和FGF-23呈正相关；与肾小球滤过率、血清血红蛋白和白蛋白呈负相关。
反映维生素K状态不佳的高dp-ucMGP水平似乎与肾脏损害有关，也可能是CKD患者心血管风险的标志物。补充维生素K2可能改善MGP的羧化状态。
