title: Serum gamma-glutamyltransferase level is associated with serum superoxide dismutase activity and metabolic syndrome in a Japanese population.
abstract: BACKGROUND
  Serum gamma-glutamyltransferase level has attracted considerable attention as a predictor of various conditions, such as cardiovascular disease and cancer. Although the mechanism that links the serum gamma-glutamyltransferase level to these diseases is not fully understood, one explanation is that gamma-glutamyltransferase may be closely related to oxidative stress. We conducted a large cross-sectional study to evaluate the relationship between serum gamma-glutamyltransferase and oxidative stress.
  
  
  METHODS
  We examined anti-oxidative stress activity and accumulation of oxidative stress in serum obtained from 2907 subjects who underwent a complete health check-up. We used serum total superoxide dismutase activity as an index of anti-oxidative stress activity. Superoxide dismutase is one of the most important intracellular and extracellular defense systems against superoxide, but the relationship between serum superoxide dismutase activity and the serum gamma-glutamyltransferase level is unclear.
  
  
  RESULTS
  The serum gamma-glutamyltransferase level was negatively correlated with serum superoxide dismutase activity, a correlation that was observed even within the normal range. A subgroup analysis stratified by the amount of alcohol consumed also showed a similar correlation. In contrast, the serum gamma-glutamyltransferase level was positively correlated with serum lipid peroxide level, even in the normal range. Furthermore, an increased serum gamma-glutamyltransferase level was significantly associated with the progression of metabolic syndrome and carotid artery intima-media thickness.
  
  
  CONCLUSIONS
  The serum gamma-glutamyltransferase level, even in the normal range, was significantly associated with anti-oxidative stress activity, the accumulation of oxidative stress, metabolic syndrome, and atherosclerosis. Measuring the serum gamma-glutamyltransferase level is simple and inexpensive, and this level can be used as a sensitive marker of oxidative stress and metabolic syndrome.
authors: Department of Gastroenterology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. n-hayato@yf7.so-net.ne.jp.|Center for Multiphasic Health Testing and Services, Mitsui Memorial Hospital, 1 Kanda-Izumi-cho, Chiyoda-ku, Tokyo, 101-8643, Japan. n-hayato@yf7.so-net.ne.jp.
authors: Hayato
authors: H
authors: Nakagawa
authors: Department of Internal Medicine, Mitsui Memorial Hospital, 1 Kanda-Izumi-cho, Chiyoda-ku, Tokyo, 101-8643, Japan.
authors: Akihiro
authors: A
authors: Isogawa
authors: Department of Gastroenterology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors: Ryosuke
authors: R
authors: Tateishi
authors: Center for Multiphasic Health Testing and Services, Mitsui Memorial Hospital, 1 Kanda-Izumi-cho, Chiyoda-ku, Tokyo, 101-8643, Japan.
authors: Mizuki
authors: M
authors: Tani
authors: Department of Gastroenterology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors: Haruhiko
authors: H
authors: Yoshida
authors: Center for Multiphasic Health Testing and Services, Mitsui Memorial Hospital, 1 Kanda-Izumi-cho, Chiyoda-ku, Tokyo, 101-8643, Japan.
authors: Minoru
authors: M
authors: Yamakado
authors: Department of Gastroenterology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors: Kazuhiko
authors: K
authors: Koike
mesh_terms: D000328:Adult; D000368:Aged; D050197:Atherosclerosis / Q000097:blood; D015415:Biomarkers / Q000097:blood; D059168:Carotid Intima-Media Thickness; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000097:blood*; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; D008054:Lipid Peroxides; D013482:Superoxide Dismutase; D005723:gamma-Glutamyltransferase