Can persistent organic pollutants explain the association between serum γ-glutamyltransferase and type 2 diabetes?

Research output: Contribution to journalArticlepeer-review

63 Scopus citations

Abstract

The results of several epidemiological studies of serum γ-glutamyltransferase (GGT) led us to hypothesise that associations of GGT within its normal range with type 2 diabetes may reflect detrimental effects of xenobiotics found in the environment, such as persistent organic pollutants (POPs). Epidemiological observations showed that serum GGT activity within its normal range strongly predicted future type 2 diabetes; the predictability of diabetes from obesity was low with GGT at the low end of the normal range; and GGT showed a positive association with known markers of oxidative stress or inflammation. Experimental findings on cellular GGT suggest that serum GGT levels within the normal range may reflect oxidative stress related to the re-synthesis of intracellular glutathione; however, this interpretation is not completely satisfying because, in its role of regenerating intracellular glutathione, GGT activity should be antioxidative. Alternatively, serum GGT activity may reflect amounts of glutathione conjugates formed during the metabolism of xenobiotics. Accordingly, we postulate a two-part hypothesis: that the association of serum GGT with type 2 diabetes reflects exposure to POPs, as these substances, which have a very long half-life, may influence diabetes risk by residing in adipose tissue as endocrine disruptors; and that POPs or similar substances may interact with obesity to cause type 2 diabetes. Supporting this hypothesis, cross-sectional investigation of background exposure to POPs in the National Health and Nutrition Examination Survey showed relationships similar to those observed for GGT, including a powerful association with prevalent diabetes and no association between obesity and diabetes for very low POP concentrations. Our hypothesis can be tested in both prospective studies and toxicological studies.

Original languageEnglish (US)
Pages (from-to)402-407
Number of pages6
JournalDiabetologia
Volume51
Issue number3
DOIs
StatePublished - Mar 2008

Keywords

  • Environmental pollutants
  • Obesity
  • Persistent organic pollutants
  • Type 2 diabetes
  • γ-Glutamyltransferase

Fingerprint

Dive into the research topics of 'Can persistent organic pollutants explain the association between serum γ-glutamyltransferase and type 2 diabetes?'. Together they form a unique fingerprint.

Cite this