Change of serum vascular adhesion protein-1 after glucose loading correlates to carotid intima-medial thickness in non-diabetic subjects

Background: We investigated if serum vascular adhesion protein-1 (SSAO/VAP-1) changed acutely following oral glucose loading and whether such changes are correlated with surrogate markers of atherosclerosis. Methods: A total of 115 non-diabetics subjects were enrolled for an oral glucose tolerance test (OGTT). Carotid intima-medial thickness (IMT) was measured by ultrasonography. Serum SSAO/VAP-1 was analyzed by time-resolved immunofluorometric assay. Serum thiobarbituric acid reactive substances (TBARS) and advanced glycated end products (AGEs) were measured by fluorometric assays. Results: Serum SSAO/VAP-1 increased significantly at 30 min after oral glucose loading and lasted to 2 h (p = 0.0005 and p <0.0001, for 30 min and 2 h respectively). The area under curve of serum SSAO/VAP-1 during OGTT (AUC-VAP-1) correlated significantly with carotid IMT, independent of age, gender, low-density lipoprotein cholesterol, systolic blood pressure, hemoglobin A1c, serum TBARS, AGEs, and high-sensitivity C-reactive protein. Subjects with a positive AUC-VAP-1 had significantly higher serum TBARS and AGEs than subjects with a negative AUC-VAP-1 adjusted for age and gender. Conclusions: Serum SSAO/VAP-1 changed acutely following oral glucose loading in non-diabetic subjects. Change of serum SSAO/VAP-1 correlated independently to serum TBARS, AGEs, and carotid IMT. Our findings suggest that acute change of serum SSAO/VAP-1 is a novel marker for hyperglycemia-induced atherosclerosis.