Treatment of obesity with diet/exercise versus pioglitazone has distinct effects on lipoprotein particle size

Atherosclerosis. 2006 Oct;188(2):370-6. doi: 10.1016/j.atherosclerosis.2005.10.038. Epub 2005 Nov 28.


Objective: We compared the effects of diet/exercise induce weight loss versus pioglitazone on lipoprotein particle characteristics in non-diabetic, insulin resistant adults to determine whether the responses and potential mechanisms for improvement are similar between these two insulin sensitizing regimens.

Methods and results: Thirty-seven obese, insulin resistant volunteers were randomized to 19 weeks of either pioglitazone or diet/exercise treatment. Insulin sensitivity (Si) by IVGTT and lipoprotein subclass particle profiles by NMR was measured. Only diet/exercise lowered TG (-40+/-11 mg/dL), total (-29+/-4 mg/dL) and LDL cholesterol (-20+/-4 mg/dL; all p<0.01). Both diet/exercise and pioglitazone improved Si (p<0.05), decreased total LDL particles (-227+/-40 and -149+/-21 nmol/L, respectively, both p<0.001) and small LDL particles (-242+/-58 and -226+/-36, respectively, both p<0.001). Large LDL particle concentrations increased with both treatments. LDL particle subclasses changes correlated with changes in Si only in the diet/exercise group.

Conclusion: In obese, insulin resistant non-diabetic adults, pioglitazone improved LDL particle characteristics in a manner similar to diet/exercise without changing TG, diabetic control, total or LDL cholesterol. This effect could have implications for atherosclerotic risk.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Blood Chemical Analysis
  • Exercise Therapy*
  • Female
  • Humans
  • Insulin Resistance / physiology
  • Lipoproteins / chemistry*
  • Male
  • Nuclear Magnetic Resonance, Biomolecular
  • Obesity / diet therapy*
  • Obesity / drug therapy
  • Obesity / therapy*
  • Particle Size
  • Pioglitazone
  • Thiazolidinediones / therapeutic use*
  • Weight Loss*


  • Lipoproteins
  • Thiazolidinediones
  • Pioglitazone