Advanced glycation end-products and advanced oxidation protein products levels are correlates of duration of type 2 diabetes

Aims: Diabetes is associated with the excess formation of advanced glycation end-products (AGEs) and advanced oxidation protein products (AOPP), and low levels of ferric reducing ability of plasma (FRAP). However, the trend of oxidative and antioxidant markers levels according to diabetes duration is unclear. Main methods: In a case-control study, 240 patients with diabetes and 100 healthy controls were enrolled. Patients were divided into four groups according to the duration of diabetes, including newly diagnosed, 1-5, 5-10, and 10-15 years. Serum AGEs, AOPP, and FRAP levels were compared among groups. Key findings: AGEs and AOPP were higher and FRAP was lower in patients with diabetes compared to healthy controls. Serum levels of AGEs increased progressively with increasing in diabetes duration. AGEs levels were 68.97 +/- 7.28% in newly-diagnosed, 73.43 +/- 12.96% in 1-5 years and 80.44 +/- 13.84% in 10-15 years of diabetes duration (pairwise p-values < 0.05). In linear regression analysis the correlation among AGEs, AOPP, FRAP, and diabetes duration remained significant after adjustment for age, BMI, HDL, HbA1c, waist circumference, microvascular complications, and coronary artery diseases. ROC analysis showed AGEs could predict the duration of diabetes when patients with 10-15 years duration of diabetes were compared to patients with 1-5 years duration of diabetes (AUC = 0.676, p-value = 0.003). Significance: Diabetes promotes AGEs, and AOPP production, independent of glycemic control and patients age. Serum levels of AGEs increase progressively with increasing duration of diabetes. AGEs may be helpful in estimating chronicity of diabetes.