September 7, 2010

Faster than a Speeding Bolus

“What the heck is that?” I thought as I read JDRF's announced initiatives aimed at speeding up insulin as part of their artificial pancreas program. Particularly this bit:
“The first will support Dr. Howard Zisser at the University of California, Santa Barbara's Sansum Diabetes Research Institute testing Roche Diabetes Care's Accu-Chek® DiaPort system. The Accu-Chek DiaPort is a percutaneous port system, connected with an external pump, that delivers insulin directly to the liver, the primary site of insulin action.”

I had no idea what a DiaPort was and I had to look up percutaneous on Wikipedia. So I asked and found some answers. Specifically I was able to talk to Dr. Andreas Stuhr, MD, who I have gotten to know through Roche’s Social Media Summits and at Friends for Life this past July.

Andreas is an all around great guy and pretty good sport. Case in point - he did a bit for theBetesNOW in German to help share the idea that diabetes community is not just a bunch of Americans. Well that what he said he said, I can’t say for sure.

Anyway he did a very good job or explaining the DiaPort and if I get anything wrong here is my bad reporting of his good explaining.

First off the DiaPort while in used in parts of Europe isn’t approved for sale here in these United States.  So no running out to your doctor for one.

It is a surgically implanted device that connects an external insulin pump to internal organs. This get the insulin close to where it would be produced without the type 1.

Part of the delay of using a traditional set is getting insulin into the program via circulation. That set just inside the skin on someone's butt is at best at outskirts of Digestion Town. The DiaPort is an express path to the downtown business district. (I made that bit up, Andreas has way too much class to use a metaphor that bad. I have no class but you know that. Shoot the messenger.)

In general DiaPort use on the other side of the pond is for cases where traditional sets don’t work well. It is used in cases such as major insulin resistance where a significant (hundreds of units daily) of insulin are needed and traditional sets aren’t up to the volume. Or where reaction to or very poor absorption from traditional subcutaneous sets makes their use impossible.

Having my Infusion Awareness Week kit handy I asked about rotation. As in how do you rotate a port? Well with the port there is not the issue of lipohypertrophy, aka the swelling of fat cells at infusion sites, that makes site rotation necessary. So no rotation.

There can be insulin crystallization. My understanding from other less reliable sources (aka the internet) is that the use of ‘log vs regular can responsible for the crystallization.

The development of artificial pancreas algorithms is facilitated by isolating out the delay inherent in traditional subcutaneous pump sets. Using the DiaPort helps that step of development. Then they can program in the delays, find faster insulin or better sets.

My thanks to Andreas for the insight into this device.

Finally, unrelated to the good doctor, if you would like to see a photo and read a users experience of a DiaPort in action here is a link.

1 comment:

Scott said...

The added benefit of the DiaPort, at least theoetically, is that insulin is delivered right to the portal vein, therefore the time-activity profile of even regular insulin is measured in minutes, not hours. Remember: there's no such thing as a natural analogue: insulin secreted endogenously does not need to be altered to prevent it from forming hexamers because it's secreted directly into the bloodstream. The insulin companies therefore don't like the DiaPort and have tried to keep it from being adopted by more because it means plan old, non-patent protected regular can be used and that insulin works faster than subcutaneously injected analogues do. Why pay more for something that regular will do better by itself when delivered directly into the blood.