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Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults
Published on: December 1, 2023
Acute free fatty acid elevation eliminates endurance training effect on insulin sensitivity
Lisa S Chow1, Elizabeth R Seaquist, Lynn E Eberly
1Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA. chow0007@umn.edu
The Journal of Clinical Endocrinology and Metabolism
|May 29, 2012
Summary
Endurance training does not protect against acute free fatty acid (FFA)-induced insulin resistance. In trained individuals, elevated FFA blunts the skeletal muscle mitochondrial mRNA response to insulin.
Area of Science:
- Exercise Physiology
- Metabolic Health
- Skeletal Muscle Biology
Background:
- Training and normal body mass index are linked to high insulin sensitivity.
- The underlying mechanisms for this association may differ between trained and sedentary individuals.
Purpose of the Study:
- To investigate if lean, trained individuals are protected from acute free fatty acid (FFA)-induced insulin resistance compared to lean, sedentary individuals.
- To explore the impact of FFA on insulin sensitivity and skeletal muscle molecular responses in different activity groups.
Main Methods:
- An interventional trial involving lean endurance-trained and sedentary participants.
- Concurrent hyperinsulinemic-euglycemic clamp with lipid or glycerol infusion.
- Measurement of glucose infusion rate (GIR) and skeletal muscle mitochondrial gene expression via biopsies.
Main Results:
- Trained individuals exhibited higher baseline insulin sensitivity and mitochondrial markers.
- Acute elevation of FFA similarly reduced insulin sensitivity (GIR) in both trained and sedentary groups.
- In trained individuals, elevated FFA abolished the stimulatory effect of hyperinsulinemia on mitochondrial mRNA levels.
Conclusions:
- Acute elevation of free fatty acids similarly impairs insulin sensitivity in both trained and sedentary humans.
- In trained individuals, FFA-induced insulin resistance is associated with altered skeletal muscle mitochondrial mRNA response to hyperinsulinemia.
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