Objective: Advanced glycation end products (AGEs) evoke inflammatory reactions, contributing to the development and progression of atherosclerosis. We investigated the relationship between serum AGE level and vascular inflammation.
Research design and methods: The study involved 275 outpatients at Kurume University, Japan (189 males and 86 females; mean age 61.2 ± 8.8 years) who underwent complete history and physical examinations and determinations of blood chemistry and anthropometric variables, including AGEs. Serum AGE level was examined by enzyme-linked immunosorbent assay. Vascular [(18)F]fluorodeoxyglucose (FDG) uptake, an index of vascular inflammation, was measured as blood-normalized standardized uptake value, known as the target-to-background ratio (TBR), by FDG-positron emission tomography (FDG-PET). Furthermore, we examined whether the changes in serum AGE level after treatment with oral hypoglycemia agents (OHAs) were correlated with those of TBR in another 18 subjects whose AGE value was >14.2 units/mL (mean ± 2 SD).
Results: Mean serum AGE level and carotid TBR values were 9.15 ± 2.53 and 1.43 ± 0.22 units/mL, respectively. Multiple stepwise regression analysis revealed that TBR was independently correlated with AGEs (P < 0.001), carotid intima-media thickness (P < 0.01), and BMI (P < 0.02). When age- and sex-adjusted AGE values stratified by TBR tertiles were compared using ANCOVA, a significant trend was observed (P < 0.01). In addition, the changes in AGEs after OHA treatment were positively (r = 0.50, P < 0.05) correlated with those in TBR value.
Conclusions: The current study reveals that serum AGE level is independently associated with vascular inflammation evaluated by FDG-PET, suggesting that circulating AGE value may be a biomarker that could reflect vascular inflammation within an area of atherosclerosis.