Effects of supervised exercise on gamma-glutamyl transferase levels in patients with isolated impaired fasting glucose and those with impaired fasting glucose plus impaired glucose tolerance

Exp Clin Endocrinol Diabetes. 2012 Sep;120(8):445-50. doi: 10.1055/s-0032-1311642. Epub 2012 May 25.


Aim: To study the effects of a supervised exercise program on serum gamma-glutamyl transferase (GGT), glycemic control and cardiovascular risk factors in pre-diabetic patients with isolated impaired fasting glucose (IFG) and those with IFG plus impaired glucose tolerance (IGT).

Methods: Out of 60 pre-diabetic patients (30 with isolated IFG and 30 with IFG + IGT) 24 were randomly assigned to the supervised exercise program (1 h twice a week) and 36 only obtained counselling on the risk of diabetes and its prevention. Patients have been followed over a 12-month period.

Results: The main findings were that patients with IFG + IGT had increased GGT levels at baseline (49.2±27.4 U/L) compared to subjects with isolated IFG (28.1±21.9 U/L) (p<0.01), and that GGT levels improved only after the supervised exercise intervention within the IFG + IGT subjects ( - 17.7±19.6 U/L). Similarly, baseline triglyceride levels were also higher in IFG + IGT patients (p<0.001) and there was a decrease through exercise intervention in these patients only (p<0.05).

Conclusion: GGT is an unspecific marker of oxidative stress and both high plasma glucose and triglycerides levels may produce oxidative stress. Thus, patients with IFG + IGT seem to have higher levels of oxidative stress than those with isolated IFG. Based on the known association between GGT levels and cardiovascular risk factors, IFG + IGT patients may be at higher risk for the development of cardiovascular diseases. The specific effect of regular exercise on GGT in pre-diabetic patients may contribute to the understanding of the preventive effects related to exercise.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Austria / epidemiology
  • Biomarkers / blood
  • Body Mass Index
  • Cardiovascular Diseases / epidemiology
  • Exercise*
  • Female
  • Glucose Intolerance / etiology
  • Glucose Intolerance / prevention & control*
  • Humans
  • Hyperglycemia / etiology
  • Hyperglycemia / prevention & control*
  • Hypertriglyceridemia / etiology
  • Hypertriglyceridemia / prevention & control
  • Male
  • Middle Aged
  • Overweight / complications
  • Oxidative Stress*
  • Prediabetic State / blood
  • Prediabetic State / complications
  • Prediabetic State / physiopathology
  • Prediabetic State / therapy*
  • Resistance Training
  • Risk Factors
  • gamma-Glutamyltransferase / blood*


  • Biomarkers
  • gamma-Glutamyltransferase
  • gamma-glutamyltransferase, human