Thursday, October 15th 2009

By unknown

SANTINO MARINUCCI

Thomas Hawke, associate professor of pathology and medicine at the Michael DeGroote School of Medicine and PhD student Karen Shortreed teamed up together to investigate how obesity caused by a high-fat diet affects the health of muscle in adolescents who are pre-diabetic. The research found that the health of young adult muscle declines during the pre-diabetic state, which is when blood sugar levels are higher than normal but lower than during Type 2 diabetes. It was discovered that there were substantial impairments to the muscle, even though it appeared to be working normally.

Hawke explained, “There is a growing epidemic of obesity and type-two diabetes in the young population that had never been there before.” When asked about why this study was conducted on adolescents and teenagers instead of older adults, he replied “In an adult muscle it may atrophy or shrink but it can actually grow back and obtain its pre-stress level. But in a young growing muscle this does not happen, and so we were interested in looking at adolescent and teenage type muscle because we think that obesity and type-two diabetes will be a significant stress [on the body] and ultimately impair that growth of the muscle.” This specific research is one of the first of its kind, so it provided an opportunity to explore the ideas of muscle generation, growth, and function in the sphere of type-two diabetes.

Hawke and Shortreed led a team of researchers at McMaster and York University in using mice to examine how a high-fat diet, leading to obesity, affected the form and function of skeletal muscle. The researchers found the high-fat diet resulted in insulin resistance, large increases in fat mass and weight gain. But it also led to initial adaptations in the muscle. Shortreed, who is first author on the article published in the scientific journal PLoS One, helped spearhead and lead this project. Shortreed explained what interested her when it came to undertaking this research with Dr. Hawke “I looked at muscle regeneration, so did a masters in muscle regeneration and in the lab in general, and began doing a lot of type-one diabetes muscle research but we already had that covered by some other graduate students so we started looking into type 2 diabetes and that there was not much out there as far as giving us a baseline on how type two diabetes is. so we Acan look at regeneration, so we decided to do the study to look at that baseline level.”

“What we hope that our study will do is just assessing muscle function itself, this may not be the best avenue in which to do that, but by the time we see the impairments in function and growth, significant changes have already happened inside the muscle,” said Hawke. He explained that in order to see significant changes in the muscle during the pre-diabetic process one would have to exercise the muscle rigorously for a significant period of time to be able to gauge the muscle strength.

In Canada, 2.4 million people are living with diabetes and up to six million more have pre-diabetes, according to the Canadian Diabetes Association. If left untreated, approximately 25 per cent of people with pre-diabetes will progress to diabetes within three to five years.

Tags: Diabetes, Muscle Health, Obesity, Thomas Hawke