title: Serum 8-hydroxy-guanine levels are increased in diabetic patients.
abstract: OBJECTIVE
  The production of reactive oxygen species is increased in diabetic patients, especially in those will poor glycemic control. We have investigated oxidative damage in type 2 diabetic patients using serum 8-hydroxyguanine (8-OHG) as a biomarker.
  
  
  METHODS
  We studied 41 type 2 diabetic patients and compared them with 3 nondiabetic control subjects. Serum 8-OHG concentration was assayed using high-pressure liquid chromatography.
  
  
  RESULTS
  The type 2 diabetic patients had significantly higher concentrations of 8-OHG in their serum than the control subjects (5.03 +/- 0.69 vs. 0.96 +/- 0.15 pmol/ml P < 0.01). There was no association between the levels of 8-OHG and HbA1c. We also could not and any correlation between serum 8-OHG levels and age, duration of diabetes, serum lipids, or creatinine or albumin exeretion rate. Creatinine clearance showed marginal correlation with serum 8-OHG levels (P = 0.06). Among the diabetic patients, those with proliferative retinopathy had significantly higher 8-OHG levels than those with nonproliferative retinopathy or without retinopathy. Likewise, the serum 8-OHG levels in patients who had advanced nephropathy (azotemia) were higher than in patients with normoalbuminuria, microalbuminuria, or overt proteinuria.
  
  
  CONCLUSIONS
  Our findings show that measuring serum 8-OHG is a novel convenient method for evaluating oxidative DNA damage. Diabetic patients, especially those with advanced microvascular complications, had significantly higher serum 8-OHG levels; this suggests that such changes may contribute to the development of microvascular complications of diabetes.
authors.affiliation: Department of Internal Medicine, the Institute of Endocrinology, Nutrition and Metabolism Research, Seoul National University College of Medicine, Korea.
authors.forename: C S
authors.initials: CS
authors.lastname: Shin
authors.forename: B S
authors.initials: BS
authors.lastname: Moon
authors.forename: K S
authors.initials: KS
authors.lastname: Park
authors.forename: S Y
authors.initials: SY
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Park
authors.forename: M H
authors.initials: MH
authors.lastname: Chung
authors.forename: H K
authors.initials: HK
authors.lastname: Lee
mesh_terms: D000419:Albuminuria; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000652:urine; D003930:Diabetic Retinopathy / Q000097:blood; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006147:Guanine / Q000031:analogs & derivatives* / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017382:Reactive Oxygen Species; D012016:Reference Values; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D002784:Cholesterol; D008076:Cholesterol, HDL; D003404:Creatinine; D006442:Glycated Hemoglobin; D006147:Guanine; D017382:Reactive Oxygen Species; D014280:Triglycerides; C024829:8-hydroxyguanine