Lift weights to control diabetes
Controlling diabetes might be easier with weight lifting as a choice for exercise. Researchers in the Life Sciences Institute at the University of Michigan have found resistance training promotes white muscle that is beneficial for glucose control instead of harmful as previously thought.
White muscle from weight lifting improves insulin response
The researchers were able to show white muscle that increase with weight lifting, running, diabetes and aging activates a pathway to make the body more responsive to insulin in mouse studies.
ATP is used by muscle for energy. With weight lifting, the muscles receive a signal to contract that in turn generates ATP from glycogen stored in white muscle. Glycogen storage is quickly depleted and only provides energy for a short period of time.
With prolonged exercise such as marathon running the red muscles take over to tap into ATP from a different source than glycogen.
The researchers for the current study explain people with diabetes have primarily white muscle that for a long time was thought to make muscles less responsive to insulin, but the there is no proof to support the theory.
Jiandie Lin, Life Sciences Institute faculty member and associate professor at the University of Michigan Medical School said in a press release: “But this idea is far from proven. You lose red muscle when you age or develop diabetes, but is that really the culprit?"
The researchers used a data base to find a protein abundant in white muscle but not in red muscle that helps white muscle develop; honing on a protein called BAF60c.
Next they developed a transgenic mouse model with BAF60c in the skeletal muscles. They discovered muscle from BAF60c transgenic mice had less mitochondria than the normal mice.
The next test was to see how the mice could run. As suspected, the BAF60c mice tired quickly, running 60 percent less time than control mice, confirming BAF60c is part of the white muscle pathway.
Once they understood how white muscle is formed they fed the mice to become obese, finding the transgenic BAF60c mice were much better at controlling their blood glucose.
"The results are a bit of a surprise to many people," Lin said. "It really points to the complexity in thinking about muscle metabolism and diabetes."
The hope is to find a drug target that promotes white muscle development to treat diabetes. For now, the researchers suggest people with diabetes lift weights for diabetes control.
April 7, 2013
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