Cyclists using insulin to dope?

I have just been listening to the Real Peloton podcast take on the Floyd Landis accusations this week. 

The nugget of information that caught my attention was that one of the products Landis confirmed he used to dope was insulin. I had never heard of insulin doping before and as a diabetic was curious to see what possible benefit could be gained...

An article from 2007 on the Royal Society of Chemistry website explains...

"...Insulin, when used as a performance enhancer, works to slow down the degradation of muscle tissue, which is attractive to such athletes as bodybuilders especially when they are also doping with a growth hormone. For endurance athletes, cyclists and runners, for example, insulin provides fuel for muscle cells and improves stamina. Although the prevalence of insulin doping is not known, luggage seizures at airports and testimonials from formerly doped athletes suggest that the abuse of this hormone is a real problem..."

On checking further there is this explanation on the Peak Performance website

"...Although it’s more usually associated with the regulation of blood glucose, the hormone insulin can also act as a powerful anabolic agent, helping to drive glucose and amino acids (the building blocks of protein) into muscle cells, thereby helping to increase glycogen synthesis and lean muscle mass. And when combined with anabolic steroids, insulin also helps prevent muscle tissue breakdown. Given the widespread availability of artificial insulin, it’s perhaps hardly surprising that growing numbers of athletes are reportedly using it in an effort to boost performance illegally..."

The next question that comes to mind is how a non-diabetic body will react to having insulin administered externally. The answers i have been able to find seem to indicate that normal insulin production via the pancreas will be suppressed and that if the practice continues the pancreas may stop functioning altogether, in short the administration of insulin to a non-diabetic patient may in fact render them diabetic.

Note: this is anecdotal information rather than something i have been able to locate on a scientific website.

Read the RSC full article here.
Read the full Peak Performance article here.