The relationship between treatment response and precursors of advanced glycation end-products in type 2 diabetes: a prospective case-control study

Background In glycolysis, hydroxyl radicals emerge via the auto-oxidation pathway in a status of hyperglycemia, and by binding to proteins or lipids, form advanced glycation end-products (AGE). Glyoxal (GO) and methylglyoxal (MGO) are precursors of AGEs. The aim of this prospective, case-control study was to investigate the difference in levels of AGE precursors in patients with and without diabetes and to investigate the relationship between the change in rates of the AGE precursors and treatment in diabetic patients. Methods The study included 21 treatment-naive patients diagnosed with type 2 diabetes and 21 age and gender-matched healthy control subjects. Throughout an observation period of 3 months, the diabetic patients were started on anti-diabetic treatment and used no additional treatment or supplementary products. The GO and MGO levels were examined with the HPLC method. Results The GO and MGO levels were determined to be 1.74 and 0.024 mu g/mL respectively in the diabetic patients and 1.14 and 0.002 mu g/mL in the control group. After 3 months of treatment, a statistically significant decrease compared to pre-treatment values was determined of 0.684 mu g/mL in GO and 0.01989 mu g/mL in MGO (p=0.001, p<0.01). No statistically significant relationship was determined between the change in HbA1c at 3 months compared to pre-treatment and the changes in GO and MGO (p>0.05). Conclusion The level of AGE precursors was found to be significantly higher in diabetic patients than in the healthy control group. Although there was a significant decrease in AGE precursors when the HbA1c level fell in patients who followed anti-diabetic treatment and diabetes-appropriate diet recommendations, this decrease was at different rates in each patient, which demonstrated that the HbA1c level is not the only determinant of AGE level in plasma. It can be concluded that with appropriate diet and antidiabetic treatment, significant reductions can be obtained in several risk factors which increase the level of AGE precursors.