title: Higher circulating GlycA, a pro-inflammatory glycoprotein biomarker, relates to lipoprotein-associated phospholipase A2 mass in nondiabetic subjects but not in diabetic or metabolic syndrome subjects.
abstract: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a cardiovascular risk marker, which is in part complexed to low-density lipoproteins, where it exerts pro-inflammatory properties. GlycA is a pro-inflammatory proton nuclear magnetic resonance spectroscopy biomarker whose signal originates from a subset of N-acetylglucosamine residues on the most abundant glycosylated acute-phase proteins.
  
  
  
  We compared plasma GlycA and Lp-PLA2 mass between subjects without type 2 diabetes mellitus (T2DM) or the metabolic syndrome (MetS) and subjects with T2DM and/or MetS. We also tested the relationship of GlycA with Lp-PLA2 in each group.
  
  
  
  Plasma GlycA, Lp-PLA2 mass, high-sensitivity C-reactivity protein (hsCRP) and lipids were measured in 40 subjects with neither T2DM nor MetS (group 1) and in 58 subjects with T2DM and/or MetS (group 2).
  
  
  
  GlycA and hsCRP were higher (P < .01 for each), whereas Lp-PLA2 was lower in group 2 vs group 1 (P < .001). GlycA was positively related to hsCRP in each group (P < .001). In contrast, GlycA was correlated positively with Lp-PLA2 in group 1 (r = 0.384, P = .015), but not in group 2 (r = 0.045; P = .74; interaction term for difference: P = .059). Although Lp-PLA2 was correlated positively with non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in each group (P ≤ .02), its inverse relationship with high-density lipoprotein cholesterol in group 1 (r = -0.381, P = .013) was absent in group 2 (r = -0.101, P = .42).
  
  
  
  A pro-inflammatory glycoprotein biomarker, GlycA, is higher in subjects with either T2DM, MetS, or both. The normally present positive relationship of GlycA with Lp-PLA2 is blunted in subjects with T2DM and/or MetS.
authors.affiliation: Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. Electronic address: e.g.gruppen@umcg.nl.
authors.forename: Eke G
authors.initials: EG
authors.lastname: Gruppen
authors.affiliation: LabCorp, Raleigh, NC, USA.
authors.forename: Margery A
authors.initials: MA
authors.lastname: Connelly
authors.affiliation: Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Robin P F
authors.initials: RP
authors.lastname: Dullaart
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D005260:Female; D006023:Glycoproteins / Q000097:blood* / Q000378:metabolism; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood; D054467:Phospholipases A2 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006023:Glycoproteins; D054467:Phospholipases A2
keywords: Diabetes mellitus; GlycA; Glycoproteins; High-sensitivity C-reactive protein; Lipoprotein-associated phospholipase A(2); Metabolic syndrome