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Of 'mighty mice' and superathletes

IGF-1: Age research may some day lead to major muscle

IGF-1: Age research may some day lead to major muscle

By Marsha Walton
CNN Sci-Tech

(CNN) -- With a lot of the world's attention focused on the Winter Games opening in Salt Lake City, it may interest athletes, coaches and fans to know about some "mighty mice" at the University of Pennsylvania Medical School.

Their muscles heal quickly after an injury; and don't show the normal signs of aging.

Their muscle mass can be 15 percent to 45 percent greater than that of normal mice.

And it's because of a gene manipulation that, if it translates to humans, could keep muscles toned and strong well into old age, and slow the progression of diseases such as muscular dystrophy.

Do you think something like IGF-1 -- if it's found to work in humans as it does in mice -- should be applied to athletic performance?

Yes, absolutely.
Under certain circumstances -- like pure fitness -- but not for competition.
No way.
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CNN's Ann Kellan talks about her interview with University of Pennsylvania physiologist Lee Sweeney  about the next step in his research on IGF-1.

"I was very much focused on something we could do that would help the elderly, because muscle weakness becomes such a major health problem," says Lee Sweeney, associate professor of physiology and medicine.

But it didn't take long for Sweeney and his research team to realize the powerful, and perhaps even alarming potential that IGF-1 (Insulin-like Growth Factor-One) could have on athletic competition.

"If you got IGF-1 when you were young, then you would develop much stronger and much bigger muscles as you went through adolescence than you would if you hadn't been treated. So it would change the whole sort of composition of your muscles. From an athletic standpoint, this would be a big advantage, but from an ethical standpoint, it might not be viewed as a proper thing to do," said Sweeney.

'The seasons of your life'

What do some world-class athletes think about the possibility of pitchers, sprinters, or skaters performing decades longer than they can now?

Says Olympic ice skating gold medal winner Scott Hamilton: "I don't care how many of these things I can inject into my body, am I going to be able to compete with Shaquille O'Neal on the basketball court? No. Or would he be able to compete with me on the skating surface? No. So there's a lot to just basic genetics, body style, physical stature, and then the mental capability, too. There's more to sports than just being big and strong and quick."

But Hamilton says the potential for treating diseases or just easing the normal pains of aging are exciting.

"I see a lot of older people in a lot of pain," he says, "because their muscles are failing them or they don't have the right level of strength to get through a normal day. But I honestly think there's something to respecting the seasons of your life and the seasons of your career in athletics."

Olympic gold medal speed skater Dan Jansen says he's wary, too.

"If it's something you could use for health reasons, I think it's a great breakthrough," he says, "but to improve your performance athletically, I think we need to stay away from it."

Olympic skater Scott Hamilton:
Olympic skater Scott Hamilton: "There's more to sports than just being big and strong and quick."  

Mice and humans produce the protein IGF-1, which helps repair muscles and keep them toned. But after about age 30 in humans, production slows down. That means muscles begin to sag and it's harder to recover from that weekend softball or volleyball game.

The gene that's injected by the University of Pennsylvania researchers triggers additional production of IGF-1. Muscle strength is maintained and recovery from injury is as efficient as it was in youth.

In experiments so far, the strength and healing ability has lasted throughout the lives of the treated mice. But their life spans are usually just a couple of years. So it's not known how long the effects might be maintained in humans, or if there could be as yet unknown long-term side effects.

The university's research has been written up in "The Proceedings of the National Academy of Sciences," "The Journal of Cell Biology" and the journal "Nature." The next step in the research is to see if the same effects on strength and repair occur in dogs' muscles, and if IGF-1 injections can slow the progression of muscle deterioration in dogs diagnosed with muscular dystrophy.

Concern about superathletics

It may not be a question of "if", but rather "when" amateur and professional athletic organizations will have to deal with IGF-1, or other gene alterations used by competitors.

"I think athletic competition at the world level is going to change," says researcher Sweeney. "We're going to have competitions essentially with people who have re-engineered their muscles, and all the records in speed and strength events are just going to go by the boards. It's a terrible thing, because it will make a mockery of all the competition of the past."

Sweeney says the technology to create and inject IGF-1 is "not something you could do today in your garage." But he says that if a country had the money and motivation to win a particular a Olympic event, then making IGF-1, packaging it and injecting athletes with it could happen "tomorrow."

Laboratory mice at the University of Pennsylvania seem to hold the beneficial effects of IGF-1 throughout their lives. There's no way to know now if humans could expect such prolonged results.
Laboratory mice at the University of Pennsylvania seem to hold the beneficial effects of IGF-1 throughout their lives. There's no way to know now if humans could expect such prolonged results.  

Members of the World Anti-Doping Agency (WADA) will look at this and numerous other sports-related genetic issues at an international meeting in March in New York.

The WADA was created in 1999 to deal with doping issues in the Olympics and other competitions. Communication director Isabelle Tornare says this will be the first major international conference on the emerging and possibly troubling questions of genetic alteration and genetic enhancement in the sports world.

These are questions that must be addressed, says Sweeney.

"The good this can bring to people with muscle disease and the elderly far outweighs the potential downside from an athletic standpoint," he says, "so I think it's going to have to be dealt with."

Note: CNN Ann Kellan has a report on the IGF-1 research on this week's Next@CNN at 1 p.m. EST on Saturday and 4 p.m. EST on Sunday.


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