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Pioglitazone-induced improvements in insulin sensitivity occur without concomitant changes in muscle mitochondrial
Sudip Bajpeyi1, Magdalena Pasarica2, Kevin E Conley3
1Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA; Department of Kinesiology, University of Texas in El Paso, 500 University Ave, El Paso, TX 79968, USA.
Metabolism: Clinical and Experimental
|March 14, 2017
Summary
Pioglitazone improves insulin sensitivity and metabolic flexibility in type 2 diabetes patients by altering muscle lipid distribution. This enhancement in fuel utilization is independent of changes in maximal ATP synthetic capacity.
Area of Science:
- Endocrinology and Metabolism
- Skeletal Muscle Physiology
- Type 2 Diabetes Research
Background:
- Pioglitazone (Pio) is recognized for enhancing insulin sensitivity in skeletal muscle.
- The precise effects of Pio on skeletal muscle lipid metabolism and oxidative capacity remain incompletely understood.
Purpose of the Study:
- To investigate the impact of chronic pioglitazone treatment on skeletal muscle mitochondrial activity.
- To determine how pioglitazone influences lipid metabolism and insulin responsiveness in individuals with type 2 diabetes.
Main Methods:
- A 12-week randomized controlled trial involving 24 type 2 diabetes participants.
- Assessment of insulin sensitivity (clamp), metabolic flexibility (ΔRQ), intramyocellular (IMCL) and extramyocellular lipid (EMCL) content (1H-MRS), and maximal ATP synthetic capacity (ATPmax) (31P-MRS).
Main Results:
- Pioglitazone treatment significantly improved insulin sensitivity and metabolic flexibility.
- A notable decrease in IMCL and increase in EMCL was observed in key leg muscles.
- Maximal ATP synthetic capacity (ATPmax) remained unchanged following pioglitazone intervention.
Conclusions:
- Pioglitazone effectively enhances insulin sensitivity, metabolic flexibility, and lipid distribution in skeletal muscle after 12 weeks.
- These improvements in insulin responsiveness and fuel utilization occur independently of alterations in mitochondrial function.
- The findings suggest a complex interplay between pioglitazone, lipid handling, and metabolic regulation in skeletal muscle.
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