We recently mentioned a product called DiaPort from Roche, invented way back in 1998, which insulin researchers have been talking about lately as a possible alternative to the implantable insulin pump! Say what? you may ask. What makes this injection port with internal tubing so powerful? Especially when there's a newer product called iPort that seems to do the same thing, possibly more elegantly?
Well, the DiaPort must be surgically implanted, and its advantage is all about the loooong tubing that actually reaches all the way into the abdominal cavity, ending near the liver.
This allows it to release insulin inside the body instead of in subcutaneous tissue, which helps speed up insulin's action — because you don't have to wait for the insulin to go through the fat and then into the blood stream. It starts working right where you need it to. Why the liver? The liver naturally releases sugar during the day, but at mealtimes, most of the sugar we eat is stored for later. When insulin is released near the liver, it quickly signals to the liver to go into storage-mode, rather than glucose-release mode.
DiaPort can connect to an external insulin pump, possibly making an implantable insulin pump unnecessary, because now you have the deep internal delivery of insulin without having to implant a whole pump inside the patient!
Authorities are still gunning for a new form of concentrated insulin to be used for internal delivery. But DiaPort already helps solve the fundamental problem of too-slow insulin, which according to physicians working with JDRF, is one of the biggest stumbling blocks right now in creating an Artificial Pancreas that works well.
Current "fast-acting" insulin takes anywhere from 15 to 20 minutes to start working, up to 90 minutes to peak, and can stay in the system for several hours. And that's the Speedy Gonzales-version? On the "Most Wanted List" for diabetes researchers (and us PWDs!) is insulin that mimics the action of naturally-produced insulin, which is lightening fast and does not stay in the system much past digestion. Although it's been around for over a decade, Roche's DiaPort is now making a resurgence in research thanks to a new push to get insulin into the system faster than ever before.
Originally the DiaPort was used only in Europe for people with "brittle " diabetes — an old-school term for bizarrely unpredictable blood sugars that skyrocket or plummet very frequently within short periods of time, seemingly for no logical reason. "Brittle" goes above and beyond just your typical "bad diabetes day."
The only online record we could find of a patient using the DiaPort is Lesley Jordan, a UK woman with type 1 who had difficulty managing her diabetes because of lipohypertrophy (poor absorption through the skin). On the UK Insulin Pumpers website, Lesley describes what the DiaPort is like to use:
Daily care was a bit daunting at first, but then so was daily care of the infusion sites when I started pumping. After a month, I didn't need to wear a wound dressing. Now I just have to clean the area with an alcohol swab every day, and make sure I only handle it with clean hands. But isn't that the same with subcut infusions?
Lesley actually had difficulty with insulin resistance while using the DiaPort, but that does not seem to be common. In fact, Roche reports that in studies, most people respond extremely well to the product. In 2009, one study of the DiaPort system comparing it with Lantus, episodes of severe hypoglycemia in patients using the DiaPort system were reduced sevenfold, but their A1c still fell by nearly 2%.
"This may be because they experienced quicker insulin absorption, earlier peak of insulinemia, quicker return to baseline insulin level and a lower peripheral insulin level," explains Dr. Andreas Stuhr, Medical Director at Roche Diabetes.
Roche is currently working on a redesign of the DiaPort system, which among other things will address some of the skin irritation issues, infection prevention, easier implantation to make the surgery less invasive, and "a more robust membrane which allows a longer use."
JDRF is also funding research on the DiaPort system. As announced last summer, their first grant funds work being done by Dr. Howard Zisser at the Sansum Diabetes Center in Santa Barbara, CA. The goal is to use the DiaPort in an Artificial Pancreas system. They'll be collaborating with Dr. Eric Renard in France on an upcoming clinical study this fall. Why France? Because the DiaPort system is not yet approved in the United States... for anything! That's one thing currently on Roche's to-do list.
Keep in mind that when used on its own, DiaPort is a solution specifically for people with severe insulin resistance, insulin allergies or other conditions that prevent insulin from being properly absorbed via injections or usual pump therapy.
"At this time we are taking the necessary steps to apply for the proper designations for this product to be used in the United States," Dr. Stuhr says. But he did not indicate there was any timeline to share, even about FDA evaluations, and there is some speculation that FDA will have to approve each individual type of indication and use before DiaPort can be used in patients. *sigh*
Fingers crossed for this little internal tubing with big potential.
If any of our European readers have seen or used the DiaPort system, we'd love to hear from you!