title: Serum gamma-glutamyl transferase levels are associated with metabolic syndrome in community-dwelling individuals.
abstract: OBJECTIVE
  Serum gamma-glutamyl transferase (GGT) activity changes in response to oxidative stress. Metabolic syndrome (MetS) is associated with an increased risk of major cardiovascular events. Few data are available on the association between serum GGT and the prevalence of MetS among community-dwelling individuals in Japan.
  
  
  METHODS
  We recruited 793 men (mean age, 60+/-14 years), and 1,073 women (62+/-12 years), free from any history relating to cardiovascular disease during their annual health examination, from a single community. We performed a cross-sectional study to examine whether serum GGT was associated with MetS.
  
  
  RESULTS
  The levels of most confounding characteristics varied with increasing GGT activity. After adjustment for age, smoking status, drinking status, low-density lipoprotein cholesterol, uric acid, estimated glomerular filtration rate and alanine aminotransferase, the odds ratios (95% confidence interval) for MetS increased across serum GGT tertiles (1, 2.23 (1.224.07), and 2.32 (1.184.56) in men; and 1, 1.43 (0.812.51), and 2.64 (1.504.64) in women). After additional adjustment for insulin resistance markers (immuno-reactive insulin or homoeostasis model assessment of insulin resistance index), the association was attenuated and the linear relation no longer significant in both genders. Furthermore, serum GGT was significantly associated with the presence of individual components of MetS in both genders, except for dyslipidemia in men and hypertension in women.
  
  
  CONCLUSIONS
  These results suggested that higher serum GGT was significantly associated with MetS and its components in the general population. This association was related with insulin resistance but was independent of other confounding factors.
authors.affiliation: Department of Internal Medicine, Seiyo Municipal Nomura Hospital, Ehime, Japan. rykawamo@yahoo.co.jp
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Kawamoto
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kohara
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Tabara
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Miki
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Otsuka
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D007564:Japan / Q000453:epidemiology; D024821:Metabolic Syndrome / Q000201:enzymology* / Q000453:epidemiology; D008875:Middle Aged; D016017:Odds Ratio; D012111:Residence Characteristics; D012307:Risk Factors; D012737:Sex Factors; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D005723:gamma-Glutamyltransferase