Clinical Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2005; 11(45): 7109-7117
Published online Dec 7, 2005. doi: 10.3748/wjg.v11.i45.7109
Associations between γ-glutamyl transferase, metabolic abnormalities and inflammation in healthy subjects from a population-based cohort: A possible implication for oxidative stress
Simona Bo, Roberto Gambino, Marilena Durazzo, Sabrina Guidi, Elisa Tiozzo, Federica Ghione, Luigi Gentile, Maurizio Cassader, Gian Franco Pagano
Simona Bo, Roberto Gambino, Marilena Durazzo, Sabrina Guidi, Elisa Tiozzo, Federica Ghione, Maurizio Cassader, Gian Franco Pagano, Department of Internal Medicine, University of Turin, Italy
Luigi Gentile, Diabetic Clinic, Hospital of Asti, Italy
Author contributions: All authors contributed equally to the work.
Supported by a grant: “Progetto di Ricerca Sanitaria Finalizzata, Regione Piemonte, 2003”
Correspondence to: Simona Bo, Dipartimento di Medicina Interna, Universita’ di Torino, Corso Dogliotti 14, 10126 Torino, Italy.
Telephone: +39-11-6967864 Fax: +39-11-6634751
Received: March 31, 2005
Revised: April 13, 2005
Accepted: April 18, 2005
Published online: December 7, 2005

AIM: To examine the relationships between γ -glutamyl-transferase (GGT), alanine-aminotransferase (ALT), aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stress marker (nitrotyrosine, NT) in subjects without any metabolic abnormalities from a population-based sample.

METHODS: Two hundred and five subjects with normal body mass index (BMI), glucose tolerance, and without any metabolic abnormality were studied out of 1 339 subjects, without known liver diseases, alcohol abuse or use of hepatotoxic drugs, who are representative of the 45-64 aged population of Asti (north-western Italy).

RESULTS: In all patients metabolic parameters and hs-CRP levels linearly increase from the lowest to the highest ALT and GGT tertiles, while in subjects without metabolic abnormalities, there is a significant association between fasting glucose, uric acid, waist circumference, hs-CRP, triglyceride values, and GGT levels. In these subjects, male sex, higher hs-CRP and glucose levels are associated with GGT levels in a multiple regression model, after adjustments for multiple confounders. In the same model, median NT levels are significantly associated with the increasing GGT tertile (β = 1.06; 95%CI 0.67-1.45), but not with the AST and ALT tertiles. In a multiple regression model, after adjusting for age, sex, BMI, waist, smoking, and alcohol consumption, both NT (β = 0.05; 95%CI 0.02-0.08) and hs-CRP levels (β = 0.09; 95%CI 0.03-0.15) are significantly associated with fasting glycemia.

CONCLUSION: GGT, an easy, universally standardized and available measurement, could represent an early marker of sub-clinical inflammation and oxidative stress in otherwise healthy individuals. Prospective studies are needed to establish if GGT could predict future diabetes in these subjects.

Keywords: Alanine aminotransferase, Aspartate aminotransferase, Body mass index, C-reactive protein, γ-Glutamyl transferase, Metabolic syndrome, Nitrotyrosine