Uncarboxylated matrix Gla protein (ucMGP) is associated with coronary artery calcification in haemodialysis patients

• Published in: Thrombosis and haemostasis Vol. 101; no. 2; p. 359
• Main Authors: Cranenburg, Ellen C M, Brandenburg, Vincent M, Vermeer, Cees, Stenger, Melanie, Mühlenbruch, Georg, Mahnken, Andreas H, Gladziwa, Ulrich, Ketteler, Markus, Schurgers, Leon J
• Format: Journal Article
• Language: English
• Published: Germany 01.02.2009
• Subjects: Adult; Aged; Aged, 80 and over; Biomarkers - blood; Calcinosis - blood; Calcinosis - complications; Calcinosis - diagnostic imaging; Calcium-Binding Proteins - blood; Coronary Angiography - methods; Coronary Artery Disease - blood; Coronary Artery Disease - complications; Coronary Artery Disease - diagnostic imaging; Cross-Sectional Studies; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix Proteins - blood; Female; Germany; Humans; Kidney Failure, Chronic - blood; Kidney Failure, Chronic - complications; Kidney Failure, Chronic - diagnostic imaging; Kidney Failure, Chronic - therapy; Male; Matrix Gla Protein; Middle Aged; Netherlands; Predictive Value of Tests; Protein Processing, Post-Translational; Renal Dialysis; Severity of Illness Index; Tomography, X-Ray Computed
• ISSN: 0340-6245
• DOI: 10.1160/TH08-04-0241

Matrix gamma-carboxyglutamate (Gla) protein (MGP) is a potent local inhibitor of cardiovascular calcification and accumulates at areas of calcification in its uncarboxylated form (ucMGP). We previously found significantly lower circulating ucMGP levels in patients with a high vascular calcification burden. Here we report on the potential of circulating ucMGP to serve as a biomarker for vascular calcification in haemodialysis (HD) patients. Circulating ucMGP levels were measured with an ELISA-based assay in 40 HD patients who underwent multi-slice computed tomography (MSCT) scanning to quantify the extent of coronary artery calcification (CAC). The mean ucMGP level in HD patients (193 +/- 65 nM) was significantly lower as compared to apparently healthy subjects of the same age (441 +/- 97 nM; p < 0.001) and patients with rheumatoid arthritis (RA) without CAC (560 +/- 140 nM; p < 0.001). Additionally, ucMGP levels correlated inversely with CAC scores (r = -0.41; p = 0.009), and this correlation persisted after adjustment for age, dialysis vintage and high-sensitivity C-reactive protein (hs-CRP). Since circulating ucMGP levels are significantly and inversely correlated with the extent of CAC in HD patients, ucMGP may become a tool for identifying HD patients with a high probability of cardiovascular calcification.