title: Gamma-glutamyltransferase activity and development of the metabolic syndrome (International Diabetes Federation Definition) in middle-aged men and women: Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort.
abstract: OBJECTIVE
  Among hepatic enzymes, gamma-glutamyltransferase (GGT) is the main predictor of type 2 diabetes incidence, although it has not been shown that GGT predicts pre-diabetes states. Our aim was to study the association of GGT with the development of the metabolic syndrome (MetS).
  
  
  METHODS
  We analyzed the 3-year data from the Data from Epidemiological Study on the Insulin Resistance Syndrome prospective cohort of 1,656 men and 1,889 women without MetS at baseline, according to the International Diabetes Federation definition.
  
  
  RESULTS
  Over 3 years, 309 participants developed the MetS. After adjustment for age, alcohol intake, physical activity, smoking habits, and alanine aminotransferase (ALT), the odds ratios for incident MetS increased across baseline GGT quartiles (1, 1.96, 2.25, and 3.81 in men, P < 0.03; and 1, 1.23, 1.80, and 1.58 in women, P < 0.05). After additional adjustment for insulin resistance markers (fasting insulin or homeostasis model assessment of insulin resistance index), the association was attenuated and the linear relation no longer significant in both sexes (P = 0.08, P = 0.16). However, men in the highest in comparison to the lowest quartile of GGT retained a significant risk for incident MetS. In women, there was no longer a significant risk. GGT was significantly associated with the 3-year incidence of individual components of the MetS. The incidence of the MetS also increased with ALT, but after adjustment on GGT this association remained significant only in women.
  
  
  CONCLUSIONS
  GGT, a predictor of type 2 diabetes, was associated with a risk of incident MetS. This association was mainly related with insulin resistance but was independent of other confounding factors.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 780-IFR69, Epidemiological and Biostatistical Research, Villejuif, France. andre@vjf.inserm.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: André
authors.forename: Beverley
authors.initials: B
authors.lastname: Balkau
authors.forename: Sylviane
authors.initials: S
authors.lastname: Vol
authors.forename: Marie Aline
authors.initials: MA
authors.lastname: Charles
authors.forename: Eveline
authors.initials: E
authors.lastname: Eschwège
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology*; D008875:Middle Aged; D011446:Prospective Studies; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
chemical_list: D005723:gamma-Glutamyltransferase