[Diabetes-talk] Artificial Pancreas Research Study

Sat Apr 17 23:06:42 UTC 2010

Dear Vinny,

Earlier this week I read (using "Newsline", of course) this article in the 
Los Angeles Times.  It sounds very promising to me.  I sure wish I lived in 
the Boston area.

Thanks for spreading the news, Joy
----- Original Message ----- 
From: "Vincent Chaney" <vgc732 at optonline.net>
To: "Diabetes-Talk" <diabetes-talk at nfbnet.org>
Sent: Saturday, April 17, 2010 1:43 PM
Subject: [Diabetes-talk] Artificial Pancreas Research Study

> FYI...
>
>
>
> A very interesting article on trial research of the artificial pancreas at 
> Boston University. This research has had FDA approval and has plans to 
> extend beyond the first 24 hour test to more than 48 hours. This next test 
> will include children as well as adults. There is an interesting 
> description of the alpha and beta cell interaction as this is the first 
> research to interactively utilize insulin and glucagon in the control. 
> Should anyone have questions about glucagon, there is a good description 
> and what its purpose is.
>
>
> Diabetes News : Artificial Pancreas Successfully Controls Blood Sugar More 
> Than 24 Hours : The Diabetic News
>
>
> Artificial Pancreas Successfully Controls Blood Sugar More Than 24 Hours
> 16-Apr-2010
> April 2010 - An artificial pancreas system that closely mimics the body's 
> blood sugar control mechanism was able to maintain near-normal glucose 
> levels without causing hypoglycemia in a small group of patients. The 
> system, combining a blood glucose monitor and insulin pump technology with 
> software that directs administration of insulin and the 
> blood-sugar-raising hormone glucagon, was developed at Boston University 
> (BU).
>
> The first clinical trial of the system was conducted at Massachusetts 
> General Hospital (MGH) and confirmed the feasibility of an approach 
> utilizing doses of both hormones. In their report, appearing in Science 
> Translational Medicine, the researchers also found unexpectedly large 
> differences in insulin absorption rates between study participants, 
> differences they were able to account for by adjustments to the system.
>
> "This is the first study to test an artificial pancreas using both insulin 
> and glucagon in people with type 1 diabetes. It showed that, by delivering 
> both hormones in response to frequent blood sugar tests, it is possible to 
> control blood sugar levels without hypoglycemia, even after 
> high-carbohydrate meals," says Steven Russell, MD, PhD, of the MGH 
> Diabetes Unit, who co-led the research team with Edward Damiano, PhD, of 
> the BU Department of Biomedical Engineering.
>
> In type 1 diabetes, the insulin-producing beta cells of the pancreas are 
> destroyed by the immune system, requiring insulin treatment to regulate 
> blood sugar levels. Intensive glucose control involving frequent blood 
> sugar testing and insulin administration can delay or prevent long-term 
> complications - such as retinal damage, kidney failure, or cardiovascular 
> disease - but is extremely demanding and difficult to maintain. Continuous 
> glucose monitors and insulin pumps can help, but patients remain at risk 
> for hypoglycemia, a potentially life-threatening drop in blood sugar 
> caused by too much insulin.
>
> Because any administration of insulin, even by an artificial pancreas 
> system, has been associated with the risk of hypoglycemia, BU 
> investigators Damiano and lead author Firas El-Khatib, PhD, developed a 
> system that both accounts for the rate of insulin absorption and also 
> incorporates glucagon, a hormone naturally released by the pancreas to 
> raise blood sugar levels. While the alpha cells of the pancreas that 
> produce glucagon are not destroyed in people with type 1 diabetes, the 
> cells no longer release glucagon in response to low blood sugar.
>
> "Large doses of glucagon are used as a rescue drug for people with 
> severely low blood sugar," explains Damiano. "Our system is designed to 
> counteract moderate drops in blood sugar with minute doses of glucagon 
> spread out throughout the day, just as the body does in people without 
> diabetes." In 2007 Damiano's team tested the system in diabetic pigs, 
> which led to FDA approval of the human trial.
>
> The current study enrolled 11 adults with type 1 diabetes and was 
> primarily designed to test the software that controls the system. To get 
> the most accurate glucose levels, the system used a monitor that directly 
> reads blood sugar through a sensor placed into a vein instead of a 
> continuous glucose monitor that takes readings under the skin.
>
> Participants' blood sugar was controlled by the system for 27 hours, 
> during which time they ate three standardized, high-carbohydrate meals and 
> slept through the night at the hospital. While the system kept glucose 
> levels close to the target range for six participants, five others 
> experienced hypoglycemia significant enough that they needed a dose of 
> orange juice to raise their blood sugar.
>
> Close analysis of participants' blood-insulin levels revealed a nearly 
> fourfold difference in the rate at which individuals absorbed and cleared 
> the fast-acting insulin used in the study, with some rates of absorption 
> being much slower than anticipated. Since the controlling software 
> determined dosage based on the expected rate of insulin absorption, 
> participants who absorbed at a slower rate received excessive doses, 
> leading to hypoglycemia.
>
> A test of participants' response to a single insulin injection verified 
> that some had consistently slow and some consistently fast rates of 
> insulin absorption. Rates of absorption also varied too much from 
> experiment to experiment, even on an individual basis, to allow 
> participant-specific dosage calculations.
>
> After globally adjusting the software parameters to a slower insulin 
> absorption rate, the researchers conducted repeat experiments in the same 
> participants. This time none of the slow-absorption participants 
> experienced hypoglycemia significant enough to require intervention.
>
> Blood-sugar levels were only slightly higher in repeat experiments 
> involving participants with fast insulin absorption, showing that the 
> adjusted software parameters were effective for all study participants and 
> may be adequate for everyone with type 1 diabetes.
>
> The elimination of episodes of hypoglycemia in repeat experiments 
> involving the same participants affirmed that the initial mismatch between 
> parameter settings and insulin absorption rate had been the cause of the 
> hypoglycemia. All previous reported studies of artificial pancreas systems 
> have included episodes of hypoglycemia, but this is the first study to 
> confirm and address the cause of that hypoglycemia.
>
> Later this spring the researchers will begin a follow-up study with a 
> system using the revised settings and driven by an FDA-approved continuous 
> glucose monitor. Those experiments will last more than 48 hours and 
> include children as well as adults. The investigators also plan to compare 
> the insulin/glucagon system with a version that uses only insulin.
>
> "The device we ultimately envision will be wearable and incorporate a 
> glucose sensor inserted under the skin that communicates wirelessly with a 
> pump about the size of a cell phone," says Russell, who is an instructor 
> in Medicine at Harvard Medical School. "The pump would administer insulin 
> and probably glucagon, and would contain a microchip that runs the control 
> software."
>
> Damiano, whose 11-year-old son was diagnosed with type 1 diabetes at the 
> age of 1, adds, "A system like this would replace the need for people to 
> constantly check their blood sugar and to make treatment decisions every 
> few hours. It would need to be maintained but could take over the 
> decision-making process, closely emulating a functioning pancreas. It 
> wouldn't be a cure, but it has the potential to be the ultimate evolution 
> of insulin therapy for type 1 diabetes."
>
> Damiano is an associate professor of Biomedical Engineering at Boston 
> University. The study was supported by grants from the Juvenile Diabetes 
> Research Foundation, the Wallace H. Coulter Foundation, the Charlton Fund 
> for Innovative Research in Diabetes and the National Center for Research 
> Resources. Co-authors of the Science Translational Medicine paper are 
> David M. Nathan, MD, director of the MGH Diabetes Center, and Robert 
> Sutherlin, RN, also of the MGH Diabetes Center.
>
> Source: Boston University
>
>
>
>
> Vinny
> Vincent Chaney Jr
> NFB Diabetes Action Network (DAN) Board
> NFBNJ Diabetes Division President
> NJAGDU Division President
> NFBNJ Technology Division Vice President
> NFBNJ.ORG Webmaster
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