title: Serum elevated gamma glutamyltransferase levels may be a marker for oxidative stress in Alzheimer's disease.
abstract: BACKGROUND
  Gamma glutamyltransferase (GGT) plays a role in cellular glutathione uptake, which is an important element of antioxidant mechanisms. An increase in serum GGT is thought to be an early and sensitive marker of oxidative stress. Oxidative stress has a role in the pathogenesis of Alzheimer's disease (AD). The aim of this study was to investigate the GGT levels in AD.
  
  
  METHODS
  In this cross-sectional study, 132 patients with AD (mean age: 74.1 +/- 7.4, female 62.9%) and 158 age- and gender-matched normal controls (mean age: 74.5 +/- 6.3, female 67.1%) were evaluated. For cognitive assessment, MMSE and clock drawing tests were performed; DSM-IV and NINCDS-ADRDA criteria were used. Serum GGT, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase concentrations were determined.
  
  
  RESULTS
  Median (min-max) GGT levels were 18 (9-70) in AD group and 17 (5-32) in normal controls. Mann-Whitney U test showed that GGT levels were significantly higher in AD patients (p = 0.012). Linear regression analysis revealed AD was an independent correlate of elevated GGT levels. Hypertension, diabetes mellitus, total cholesterol, and low density lipoprotein cholesterol were not associated with GGT levels.
  
  
  CONCLUSIONS
  GGT levels were increased significantly in AD patients. To evaluate the role of GGT as a marker of oxidative stress in AD, further studies are needed.
authors.affiliation: Hacettepe University Faculty of Medicine, Department of Internal Medicine, Division of Geriatric Medicine, Ankara, Turkey. bbyavuz@hacettepe.edu.tr
authors.forename: Burcu Balam
authors.initials: BB
authors.lastname: Yavuz
authors.forename: Bunyamin
authors.initials: B
authors.lastname: Yavuz
authors.forename: Meltem
authors.initials: M
authors.lastname: Halil
authors.forename: Mustafa
authors.initials: M
authors.lastname: Cankurtaran
authors.forename: Zekeriya
authors.initials: Z
authors.lastname: Ulger
authors.forename: Eylem Sahin
authors.initials: ES
authors.lastname: Cankurtaran
authors.forename: Kudret
authors.initials: K
authors.lastname: Aytemir
authors.forename: Servet
authors.initials: S
authors.lastname: Ariogul
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000410:Alanine Transaminase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D000544:Alzheimer Disease / Q000175:diagnosis / Q000201:enzymology*; D001219:Aspartate Aminotransferases / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000201:enzymology; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D018384:Oxidative Stress / Q000502:physiology*; D012016:Reference Values; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002784:Cholesterol; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase