Objective: Advanced glycation end products (AGEs) are a complex and heterogenous group of proteins that are formed by nonenzymatic glycation in a series of reactions. It is hypothesized that they may play a role in the pathogenesis of diabetes-related complications; at present, however, their exact biological role is scarcely understood. Clinical studies so far have shown that serum levels of AGEs are correlated with clinical stages of diabetes complications such as retinopathy and nephropathy. This study was performed in children and adolescents with type 1 diabetes to examine the putative role of serum AGEs in respect to metabolic control and diabetes complications in relation to a number of clinical and laboratory parameters.
Research design and methods: We studied 99 children and adolescents up to the age of 20 years with type 1 diabetes and 60 control subjects. Serum levels of AGEs were measured with two different methods [fluorescence spectroscopy and Nepsilon-(carboxymethyl)lysine (CML) enzyme-linked immunosorbent assay] and correlated with clinical data, such as age, diabetes duration, BMI, and long-term metabolic control determined by HbA(1c), and laboratory parameters, such as serum lipids.
Results: Serum levels of fluorescent AGEs, but not of CML-AGEs, in children and adolescents with type 1 diabetes were significantly higher compared with control subjects. There was an age-dependent increase of fluorescent AGEs in children and adolescents with diabetes that was not seen in healthy children and adolescents. Levels of fluorescent AGEs in patients with diabetes between 13 and 16 years of age correlated positively with HbA(1c) levels. No significant association between levels of AGEs and diabetes duration was found. Children and adolescents with diabetes and high serum triglycerides had significantly higher serum levels of fluorescent AGEs. Children and adolescents with diabetes between the age of 13 and 16 years with high levels of LDL had significantly higher levels of fluorescent AGEs.
Conclusions: In this study we demonstrated a clear age-dependent increase of fluorescent AGEs but not of CML-AGEs in children and adolescents with diabetes type 1. Moreover we showed a strong association between serum AGEs and serum triglycerides and cholesterol. The observed effect may be caused by a loss of optimal regulation of lipid metabolism. It could suggest a link between triglycerides and formation of AGEs. This new and interesting finding and its impact on metabolic control and the development of diabetes complications should be examined in the future.