[Diabetes-talk] Artificial Pancreas Research Study

Sun Apr 18 15:59:51 UTC 2010

Wonder if the bg sensers are any better than those used now in the 
continuous glucose monitoring systems? Having to recalibrate at least once a 
day with fingersticks makes me wonder just how accurate the hormone dosage 
guesses by the machines would be.

Mike

----- Original Message ----- 
From: "Joy Stigile" <jstigile at sbcglobal.net>
To: "Diabetes Talk for the Blind" <diabetes-talk at nfbnet.org>
Sent: Saturday, April 17, 2010 4:06 PM
Subject: Re: [Diabetes-talk] Artificial Pancreas Research Study

> 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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>
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