title: Possible link between glycated hemoglobin and lipid peroxidation in hyperthyroidism.
abstract: BACKGROUND
  Glycated hemoglobin (HbA1C) levels are enhanced by elevated glucose concentrations. Glycation of hemoglobin is also modulated by lipid peroxides, ascorbic acid and reduced glutathione (GSH). We determined the strength of the relationships among these variables in a group of hyperthyroid patients.
  
  
  METHODS
  Twenty-two untreated hyperthyroid patients and 17 healthy controls were recruited for the study. Whole blood GSH, HbA1C, plasma lipid peroxides, ascorbic acid and fasting glucose were analyzed in both the groups. Direct and partial correlation analysis was performed to explore the possible relationships between these variables.
  
  
  RESULTS
  In hyperthyroid patients, HbA1C and lipid peroxides levels were found to be significantly increased than the controls. Ascorbic acid and GSH were decreased significantly in the test group when compared with the healthy control group. With partial correlation analysis, fasting glucose and lipid peroxides were found to have a significant positive correlation with HbA1C. Ascorbic acid and GSH showed no significant association with HbA1C levels.
  
  
  CONCLUSIONS
  These data suggest that HbA1C levels are closely associated with fasting glucose and lipid peroxides in hyperthyroid patients. Therefore, serum lipid peroxides level should be kept in mind while interpreting HbA1C as a long-term glycemic index in hyperthyroid cases.
authors.affiliation: Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry 605 006, India.
authors.forename: K M
authors.initials: KM
authors.lastname: Mohan Kumar
authors.forename: Zachariah
authors.initials: Z
authors.lastname: Bobby
authors.forename: N
authors.initials: N
authors.lastname: Selvaraj
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar Das
authors.forename: Bidhan
authors.initials: B
authors.lastname: Chandra Koner
authors.forename: S K
authors.initials: SK
authors.lastname: Sen
authors.forename: R
authors.initials: R
authors.lastname: Ramesh
authors.forename: P
authors.initials: P
authors.lastname: Ranganathan
mesh_terms: D000293:Adolescent; D000328:Adult; D001205:Ascorbic Acid / Q000097:blood; D001786:Blood Glucose; D016022:Case-Control Studies; D005260:Female; D005978:Glutathione / Q000097:blood; D006442:Glycated Hemoglobin / Q000096:biosynthesis*; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood*; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D001205:Ascorbic Acid; D001786:Blood Glucose; D005978:Glutathione; D006442:Glycated Hemoglobin; D008054:Lipid Peroxides