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Endocrine Care: Emilio Ortega, Juraj Koska, Arline D. Salbe, Pietro Antonio Tataranni, and Joy C. Bunt Serum -Glutamyl Transpeptidase Is a Determinant of Insulin Resistance Independently of Adiposity in Pima Indian Children J Clin Endocrinol Metab 2006; 91: 1419-1422 [Abstract] [Full text] [PDF]

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Looking for a correlation among GGT, insulin resistance and liver damage

Melania Manco, Roberto Guidi, Valerio Nobili   (7 March 2006)

Looking for a correlation among GGT, insulin resistance and liver damage 7 March 2006
Melania Manco Paediatric Hospital Bambino Gesł and Research Institute, Roberto Guidi, Valerio Nobili Send letter to journal: Re: Looking for a correlation among GGT, insulin resistance and liver damage melaniamanco{at}tiscali.it Melania Manco, et al.	The recent cross-sectional study in 44 PIMA Indian children by Ortega et al found (1) a strong relation between levels of GGT and insulin resistance, measured by the HOMA, independent of age, sex, and indexes of adiposity. Their mathematical model was able largely to explain the variance in HOMA-IR in this population. The authors speculated that GGT could be a marker of liver damage in children, as is the case in adults (2, 3), or be a marker of oxidative stress. To the best of our knowledge, few studies (4, 5) have performed liver biopsy, the gold standard to assess liver damage (2), in children with nonalcoholic fatty liver disease (NAFLD) or correlated biopsy findings with insulin resistance or oxidative stress. Schwimmer et al (4) recently found no correlation between liver damage and GGT levels, and no relation of GGT to insulin resistance in 106 NAFLD children. In 21 biopsy-proven NAFLD children, we also found no correlation between GGT and the degree of histological liver involvement. Moreover, the impairment of glutathione metabolism and antioxidant enzyme activities was again unrelated to levels of GGT (5). We believe that more data are needed in order to clarify the role of GGT in predicting insulin resistance and/or liver damage in children. References 1. Ortega E, Koska J, Salbe AD, Tataranni PA, Bunt JC. 2006. Serum Gamma- Glutamyl Transpeptidase (GGT) is a Determinant of Insulin Resistance (HOMA-IR) Independent of Adiposity in Pima Indian Children. J Clin Endocrinol Metab. (January 24, 2006:10.1210/jc.2005-1783) 2. Angulo P. 2002. Nonalcoholic fatty liver disease. N Engl J Med 346:1221-1231 3. Neuschwander-Tetri BA, Caldwell SH. 2003. Nonalcoholic steatohepatitis: summary of an AASLD Single Topic Conference. Hepatology 37:1202-1219 4. Schwimmer JB, Behling C, Newbury R, Deutsch R, Nievergelt C, Schork NJ, Lavine JE. 2005. Histopathology of pediatric nonalcoholic fatty liver disease. Hepatology 42:641-649 5. Nobili V, Pastore A, Gaeta LM, Tozzi G, Comparcola D, Sartorelli MR, Marcellini M, Bertini E, Piemonte F. 2005. Glutathione metabolism and antioxidant enzymes in patients affected by nonalcoholic steatohepatitis. Clin Chim Acta 355:105-111