Elevated serum levels of advanced glycation end products and their monocyte receptors in patients with type 2 diabetes

Abstract

Background and aims: Animal experiments showed that interaction between advanced glycation end products (AGE) and their receptors (RAGE) play an important role in the pathogenesis of diabetic complications. Soluble RAGE (sRAGE) can function as a decoy for RAGE ligands. The present study aimed to examine the levels of AGEs, RAGE and sRAGE in patients with type 2 diabetes (T2D).

Methods: RAGE gene expression was determined by real-time PCR in 50 patients with T2D (27 men, mean age 52 ± 7.7 years) and 50 age-matched controls without T2D. Serum AGEs and sRAGEs were assayed by enzyme-linked immunosorbent assay (ELISA).

Results: Serum level of AGEs was increased in patients with T2D (10.35 ± 2.27 μg/mL vs.7.69 ± 0.56 μg/mL, p <0.05). sRAGE was decreased in patients with T2D (573.6 ± 172.5 pg/mL vs. 603.4 ± 120.8 pg/mL p <0.01). RAGE gene expression was higher in T2D than in controls (p <0.01). There was an association between monocyte RAGE and serum levels of AGEs in both T2D patients (r = 0.29, p = 0.03) and controls (r = 0.31, p = 0.02). Serum AGEs correlated with homeostasis model assessment of insulin resistance (HOMA-IR) in both patients with T2D (r = 0.322, p = 0.004) and controls (r = 0.281, p = 0.003).

Conclusions: Serum AGEs and monocyte RAGE expression are increased in patients with T2D, whereas serum sRAGE is decreased. Pharmacological intervention on serum AGEs and sRAGE may be a potential therapy for diabetes.