Plasma Desphospho-Uncarboxylated Matrix Gla Protein as a Marker of Kidney Damage and Cardiovascular Risk in Advanced Stage of Chronic Kidney Disease.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Nephrology, Hypertension and Kidney Transplantation, Medical University of x0141;x00F3;dx017A;, Poland.
Ilona
I
Kurnatowska
Piotr
P
Grzelak
Anna
A
Masajtis-Zagajewska
Magdalena
M
Kaczmarska
Ludomir
L
Stefańczyk
Cees
C
Vermeer
Katarzyna
K
Maresz
Michał
M
Nowicki
D015415:Biomarkers / Q000097:blood; D002135:Calcium-Binding Proteins / Q000097:blood* / Q000187:drug effects / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000209:etiology; D016326:Extracellular Matrix Proteins / Q000097:blood* / Q000187:drug effects / Q000378:metabolism; D000089703:Fibroblast Growth Factor-23; D006801:Humans; D007668:Kidney / Q000293:injuries / Q000473:pathology; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000188:drug therapy / Q000473:pathology*; D012307:Risk Factors; D024482:Vitamin K 2 / Q000627:therapeutic use; D000097568:Matrix Gla Protein
D015415:Biomarkers; D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D000089703:Fibroblast Growth Factor-23; D024482:Vitamin K 2; D000097568:Matrix Gla Protein; C000717427:FGF23 protein, human