title: Relationship of methylglyoxal-adduct biogenesis to LDL and triglyceride levels in diabetics.
abstract: OBJECTIVE
  Protein glycation leading to advanced glycation-endproducts (AGE) is enhanced in diabetes by increased blood glucose and collateral endogenous production of reactive α-dicarbonyls. Among AGE precursors, methylglyoxal (MG) is considered as one of the key intermediates. We hypothesized it to be a common product of both carbonyl and oxidative stress, and investigated its biogenesis in relation to glycemic and lipid status in diabetic patients.
  
  
  METHODS
  Serum and urine MG-adducts were measured by competitive immunofluorometric assay in 83 diabetic and 20 healthy subjects.
  
  
  RESULTS
  A significant association of MG-adducts serum level with LDL (r=0.31;p=0.003) was observed. A correlation between LDL-c, HDL-C and PPG as independent variables and serum MG-adducts as a dependent variable was found (p<0.014) using multiple stepwise regression, whereas urine albumin/creatinine ratio was independently associated with urine MG-adducts. LDL cut-off >3.0mmol/l discriminated patients with higher serum MG-adducts (p=0.0052), although there was no between-subgroup difference in glycemic control. Patients on statin therapy had a lower MG-adduct level. The positive relationship between LDL-c and MG-adducts (r=0.38;p=0.042) was noted in patients free of statin treatment, whereas an inverse tendency was found in the statin-treated subgroup.
  
  
  CONCLUSIONS
  Significant relationship between LDL and MG-adduct production, as well as tight correlation between triglycerides and urinary MG-adduct excretion suggest that the lipoxidation and glyceraldehyde-3-phosphate route, along with the glycolytic pathway, might be an important source of MG generation. The glycotoxin methylglyoxal seems to be a common factor linking hyperglycemia and intensive lipolysis, two dominant metabolic changes in diabetes.
authors.affiliation: Vuk Vrhovac Clinic for Diabetes, Zagreb University Hospital Center, Zagreb, Croatia. zturk@idb.hr
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Turk
authors.forename: Maja
authors.initials: M
authors.lastname: Cavlović-Naglić
authors.forename: Nikša
authors.initials: N
authors.lastname: Turk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D008078:Cholesterol, LDL / Q000097:blood* / Q000652:urine*; D003920:Diabetes Mellitus / Q000097:blood* / Q000652:urine*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000652:urine; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000652:urine; D017127:Glycation End Products, Advanced / Q000097:blood / Q000652:urine; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000652:urine; D008875:Middle Aged; D011765:Pyruvaldehyde / Q000097:blood* / Q000652:urine*; D014280:Triglycerides / Q000097:blood* / Q000652:urine*
chemical_list: D008078:Cholesterol, LDL; D017127:Glycation End Products, Advanced; D014280:Triglycerides; D011765:Pyruvaldehyde