Disassociation of muscle triglyceride content and insulin sensitivity after exercise training in patients with Type 2 diabetes

Diabetologia. 2004 Jan;47(1):23-30. doi: 10.1007/s00125-003-1265-7. Epub 2003 Dec 12.

Abstract

Aim/hypothesis: We determined the effect of exercise training on insulin sensitivity and muscle lipids (triglyceride [TG(m)] and long-chain fatty acyl CoA [LCACoA] concentration) in patients with Type 2 diabetes.

Methods: Seven patients with Type 2 diabetes and six healthy control subjects who were matched for age, BMI, % body fat and VO(2)peak participated in a 3 days per week training program for 8 weeks. Insulin sensitivity was determined pre- and post-training during a 120 min euglycaemic-hyperinsulinaemic clamp and muscle biopsies were obtained before and after each clamp. Oxidative enzyme activities [citrate synthase (CS), beta-hydroxy-acyl-CoA (beta-HAD)] and TG(m) were determined from basal muscle samples pre- and post training, while total LCACoA content was measured in samples obtained before and after insulin-stimulation, pre- and post training.

Results: The training-induced increase in VO(2)peak (approximately 20%, p<0.01) was similar in both groups. Compared with control subjects, insulin sensitivity was lower in the diabetic patients before and after training (approximately 60%; p<0.05), but was increased to the same extent in both groups with training (approximately 30%; p<0.01). TG(m) was increased in patients with Type 2 diabetes (170%; p<0.05) before, but was normalized to levels observed in control subjects after training. Basal LCACoA content was similar between groups and was unaltered by training. Insulin-stimulation had no detectable effect on LCACoA content. CS and beta-HAD activity were increased to the same extent in both groups in response to training ( p<0.001).

Conclusion/interpretation: We conclude that the enhanced insulin sensitivity observed after short-term exercise training was associated with a marked decrease in TG(m) content in patients with Type 2 diabetes. However, despite the normalization of TG(m )to levels observed in healthy individuals, insulin resistance was not completely reversed in the diabetic patients.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Hydroxyacyl CoA Dehydrogenases / metabolism
  • Adipose Tissue / anatomy & histology
  • Blood Glucose / drug effects
  • Blood Glucose / metabolism
  • Body Mass Index
  • Citrate (si)-Synthase / metabolism
  • Diabetes Mellitus, Type 2 / metabolism*
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Exercise / physiology*
  • Glucose Clamp Technique
  • Humans
  • Insulin / pharmacology*
  • Middle Aged
  • Muscle, Skeletal / metabolism*
  • Oxygen Consumption
  • Physical Fitness
  • Reference Values
  • Triglycerides / metabolism*

Substances

  • Blood Glucose
  • Insulin
  • Triglycerides
  • 3-Hydroxyacyl CoA Dehydrogenases
  • Citrate (si)-Synthase