title: Impact of metabolic control and serum lipids on the concentration of advanced glycation end products in the serum of children and adolescents with type 1 diabetes, as determined by fluorescence spectroscopy and nepsilon-(carboxymethyl)lysine ELISA.
abstract: 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.
  
  
  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.
authors.affiliation: Children's Hospital, University of Leipzig, Leipzig, Germany. gala@medizin.uni-leipzig.de
authors.forename: Angela
authors.initials: A
authors.lastname: Galler
authors.forename: Grit
authors.initials: G
authors.lastname: Müller
authors.forename: Reinhard
authors.initials: R
authors.lastname: Schinzel
authors.forename: Juergen
authors.initials: J
authors.lastname: Kratzsch
authors.forename: Wieland
authors.initials: W
authors.lastname: Kiess
authors.forename: Gerald
authors.initials: G
authors.lastname: Münch
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000419:Albuminuria; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D002784:Cholesterol / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D017127:Glycation End Products, Advanced / Q000097:blood*; D006801:Humans; D008055:Lipids / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008239:Lysine / Q000031:analogs & derivatives* / Q000097:blood*; D008297:Male; D012016:Reference Values; D012044:Regression Analysis; D013050:Spectrometry, Fluorescence / Q000379:methods; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D017127:Glycation End Products, Advanced; D008055:Lipids; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; C048496:N(6)-carboxymethyllysine; D002784:Cholesterol; D008239:Lysine