Posts Tagged ‘diabetes’
Diabetes Researchers Report New Steps Towards the First Artificial Pancreas
Endocrinologists have been presenting new concepts at a meeting of the American Diabetes Association in San Diego, and last week, U.S. regulators released new draft guidelines for a new generation of devices.
Researchers at the Mayo Clinic are developing an artificial pancreas that accounts for slight, low-intensity physical activities that can impact blood sugar levels. The researchers are developing a that includes a glucose monitor, automatic insulin pump, activity monitors that attach to the body and a central computer that uses an insulin-delivery algorithm to determine how much of the hormone to dispense.
A team led by Yogish Kudva at Mayo hooked up diabetics with accelerometers to measure slight movements, and tracked their blood sugars while they moved around after eating a meal. They found that even limited, basic movements had a major impact on blood sugar levels, bringing them close to those of people with normally functioning pancreases. But insulin pumps and glucose monitors don’t account for those slight differences. New algorithms that adjust for those changes could help diabetics better manage their insulin intake, the Mayo researchers said. The team plans to start a clinical trial with the system this year or early next year, according to Bloomberg.
In another study, researchers at tested an artificial pancreas that automatically senses and regulates glucose throughout the night, and found it worked better than a traditional insulin pump. Twelve patients were hooked up to a glucose monitor manufactured by Medtronic Inc., which sent signals to a laptop, where algorithms calculated how much insulin to administer. The system is simple enough that it could eventually be integrated into a wearable device, according to the researchers.
The Food and Drug Administration last week announced for how to develop some of these systems, including a “low glucose suspend system,” which cuts off insulin delivery when blood sugar levels drop. The device is already approved in Europe.
The FDA plans to release even more detailed plans for closed-loop artificial pancreases by the end of the year, according to Bloomberg.
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An Ultra-Low-Calorie, Low-Carb Diet is Sufficient to Reverse Type 2 Diabetes, Study Finds
600 calories per day
Seven of the 11 patients remained free of diabetes three months after the study, researchers said.
Type 2 diabetes, also known as adult-onset diabetes, has been thought to be a progressive, irreversible condition. Once diagnosed, some patients can control their diabetes with tablets, but many eventually require insulin injections.
Type 2 diabetes occurs when the pancreas is unable to produce sufficient insulin to regulate fat metabolism and sugars in the blood, or when the body is unable to react to the insulin. It’s different than Type 1, or juvenile diabetes, an autoimmune disorder in which the immune system destroys the beta cells that produce insulin.
The study was announced Friday at an American Diabetes Association conference, according to Newcastle University. It is being published in the journal Diabetologia.
The study enrolled 11 patients who had developed Type 2 diabetes later in life, and restricted them to a super-low-calorie diet consisting of diet drinks and non-starchy vegetables. Over eight weeks, researchers monitored the fat content in the liver and the insulin production from the pancreas, comparing the results to a control group of non-diabetics.
After just one week, the diabetics’ pre-breakfast blood sugar levels were normal, according to the researchers. MRI scans of the patients’ pancreases revealed that fat levels had dropped, which allowed the organ to produce more insulin, the researchers said.
“To have people free of diabetes after years with the condition is remarkable - and all because of an eight week diet,” said Roy Taylor, a professor at Newcastle University who led the study and is director of the Newcastle Magnetic Resonance Centre. “We believe this shows that Type 2 diabetes is all about energy balance in the body.”
While the results are promising, researchers caution that diabetic patients should not undertake such a drastic dietary change without medical supervision. One patient, 67-year-old Gordon Parmley, ate salad and vegetables and three diet shakes per day.
“At first the hunger was quite severe and I had to distract myself with something else – walking the dog, playing golf – or doing anything to occupy myself and take my mind off food,” he said in a statement. “But I lost an astounding amount of weight in a short space of time ... after six years, I no longer needed my diabetes tablets.”
Scientists at Diabetes UK said the trial was very small, but they looked forward to future results, especially those that would show whether the diabetes reversal held true in the long term.
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Experimental “Body Reboot” Drug Begins Trial As Preemptive Preventer Of Diabetes
But a new trial, launched through the National Institutes of Health’s Type 1 Diabetes Trial Net, may change that. Headed by Kevan Herold, M.D., TrialNet Principal Investigator and Professor of Immunobiology and Medicine at Yale University, the – which is currently enrolling -- will test whether a drug called teplizumab might be able to prevent or delay Type 1 in high-risk relatives of people with the disease.
Teplizumab is what’s known as an anti-CD3 monoclonal antibody, a targeted immunosuppressive drug that I wrote about for Popular Science last . I know about teplizumab because I took it myself – after being diagnosed with Type 1 diabetes in 2001 at the age of 22, I enrolled in a study that tested whether teplizumab might preserve some insulin production in people recently diagnosed with the disease. In my case, it worked: nine years out, I was still producing a measurable amount of insulin, which in the normal course of Type 1, doesn’t happen. (I’m going in for a 10-year follow-up at the end of March.)
The results of the trial I participated in, which were published in the New England Journal of Medicine, were exciting to researchers and patients alike. But unfortunately, teplizumab is not a cure. Reversing Type 1 diabetes remains a frustratingly complicated challenge, one that would require not just replacements for the cells that have been destroyed, but a successful override of at least two different immune responses: the tendency to reject foreign tissue (transplanted insulin-producing cells would be rejected just like a transplanted kidney), and the immune reaction that triggered Type 1 to begin with.
Mindful of these challenges, researchers have long sought a way to prevent Type 1 from developing to begin with – and the results of the teplizumab studies (later corroborated by other studies using the same drug), suggested an interesting possibility. Researchers have recently discovered that Type 1 takes a long time to fully develop – autoantibodies against the insulin-producing cells can begin to develop up to 10 years before symptoms appear. Teplizumab is thought to work by shutting off the part of the immune system most responsible for attacking the insulin-producing cells. So what if it were to be given to high-risk people before they developed symptoms? Researchers like Herold hypothesize that a preemptive treatment with teplizumab might prevent those immune cells from attacking in the first place.
For people interested in the study – or simply in finding out their risk -- Trial Net offers a screening test kit, available either by mail or in person, to check for the autoantibodies that lead to Type 1. The screening is free for people 45 years old or younger with a parent, sibling, or child with Type 1 diabetes, as well as for people under 20 who have a niece, nephew, aunt, uncle, grandparent, half-sibling or cousin with the disease. People who test positive may be eligible to participate in the trial; people who test negative for the autoantibodies can be retested annually for free until they turn 18.
It can be a difficult decision to have your family members screened, especially children. But personally, I know that if I’d had the opportunity to be screened, I would have taken it – regardless of whether there were a trial to participate in. Not only could screening help you learn about possible opportunities for prevention and early treatment, but the earlier you catch Type 1, the less likely you are to develop diabetic ketoacidosis, a potentially deadly complication brought on by extremely high blood glucose levels. In my case, I might have caught the symptoms – and started insulin – before I landed in the hospital for a week, bewildered and terrified to be diagnosed with a disease for which I never knew I was at risk.
The results of the Anti-CD3 Prevention Study obviously remain to be seen – previous trials to prevent Type 1 have been disappointments. Still, Herold – who has Type 1 himself – is cautiously optimistic. “There is no other trial in the world that is testing prevention of Type 1 diabetes in this particular group of people,” he says. “It’s the most exciting trial I’ve ever done.”
More information about the trial is available at .
Diabetic Men May Soon Be Able to Grow Their Own Insulin-Making Cells
Men with type-1 diabetes might be able to grow new insulin cells from their , according to a new study. Testicular treatment could even be safer and more effective than stem-cell therapies.
Researchers at Georgetown University Medical Center were able to coax human spermatogonial stem cells, which are precursors to sperm cells, into becoming adult stem cells. Sperm cells already have the genes necessary to become embryonic stem cells, the researchers point out in a Georgetown news release. This way, the researchers didn’t have to use gene therapy to create induced pluripotent stem cells (IPS cells) — “These are true, pluripotent stem cells,” said G. Ian Gallicano, an associate professor in the Department of Cell Biology and Director of the Transgenic Core Facility at GUMC.
The team took one gram of tissue from human testes from deceased organ donors and produced about one million stem cells in the lab. The cells showed many of the biological markers that characterize normal beta islet cells, which are insulin-secreting cells normally found in the pancreas. Then the team transplanted the cells into diabetic mice, and were able to decrease the animals’ glucose levels.
The proof-of-concept study could yield a new, safer treatment for type 1 diabetes, also called juvenile diabetes. Current treatments include transplanting islet cells from deceased donors, but this can result in rejection, and there are only so many donors. Researchers have cured diabetes in mice using IPS cells, but these can produce tumors as well as problems stemming from the external genes used to create IPS cells, according to Gallicano. The new method bypasses IPS cells, because sperm cells are already a form of stem cells. The study was reported Sunday at the American Society of Cell Biology 50th annual meeting in Philadelphia.
MIT’s New Glucose Meter Checks Blood Sugar Levels With Painless Infrared Light
Researchers at MIT's Spectroscopy Lab have been working for more than a decade on a method of using Raman spectroscopy to measure glucose levels. That approach involves shining near-infrared light on the patient's arm or finger and using the ensuing vibrations put off by the chemical bonds in various molecules in the skin to measure the amount of glucose present.
The method works well, but the IR light can only penetrate about half a millimeter below the skin. That means glucose readings are actually measuring the amount of sugar in the interstitial fluid surrounding skin cells rather than the bloodstream. To overcome this problem, the team developed an algorithm that relates the two different glucose concentrations so the device can extrapolate the amount of glucose in the bloodstream from the amount of glucose in the skin.
But another problem persisted: directly after eating, a patient's blood glucose soars. His or her interstitial fluid levels might take up to ten minutes to catch up, resulting in a faulty reading. To deal with this lag, the team developed another method of correcting for the difference between blood glucose and skin glucose levels called Dynamic Concentration Correction (DCC). By adding the rate at which glucose diffuses from blood to skin into the larger equation, they found they were able to improve the accuracy of their readings by up to 30 percent in the best cases and 15 percent on average.
Raman spectroscopy still isn't perfect, but the breakthrough is a pretty big step toward solving a problem that has persisted for years with only measured progress. The MIT team plans to get a clinical trial underway on healthy patients in the fall to see if DCC can stand up in a more real-world setting. If it does, those finger-pricking meters could become a thing of the past.
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Injectable Glowing Beads In Bloodstream Can Indicate Glucose Levels
Japanese "Life Beans" project aims to ease monitoring for diabetics
The system, developed at the University of Tokyo, could lead to implantable blood-glucose monitors, which could enable 24-7 monitoring of a diabetic's blood sugar without having to prick the skin or use an attachable pump.
"Beans" stands for Bioelectrical Mechanical Autonomous Nano Systems."
Researchers tested it in the ears of a mouse, and watched as the ear fluoresced at different intensities depending on the mouse's blood sugar.
The researchers think it would be possible to develop devices that manage diabetics' blood sugar without them noticing it.
The main problem is the beads' life span -- once they're implanted, the immune system kicks in and attaches proteins to the beads, which effectively dim their light. The next step is engineering a material that resists protein adhesion, the researchers say.
Learn more in this video:
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Wireless, Implantable Glucose Sensor Could Revolutionize Diabetes Treatment
The round device is just a bit smaller than a Double-Stuf Oreo -- about 1.5 inches wide and half an inch thick -- and would be implanted in a person's torso. It's hermetically sealed, with an integrated antenna that wirelessly transmits data, a long-lived battery, and a pair of sensors. One sensor detects only oxygen, the other a reaction that involves both oxygen and glucose. No matter how dense the scar tissue surrounding the implant, the two-sensor combination compensates, allowing the device to correctly calculate glucose levels in the blood.
Most complications from diabetes, from blindness to heart attacks, can be mitigated with monitoring -- obsessive monitoring that involves blood-drawing finger pricks every 15 minutes, day and night. Most diabetics don't even test every hour.
The most advanced technology currently available for continuous monitoring uses a needle-sized sensor that pokes deep into the skin, connected via a wire or wireless transmitter to a pager-sized monitor. It provides blood-sugar levels in close-to-real time, but it's also a bit bulky and inconvenient: The needle-like sensors must be recalibrated daily and replaced every three to seven days, before the body encapsulates them with scar tissue and renders it useless.
Such rapid obsolescence doesn't apply to the implantable device, which was developed by researchers at the University of California at San Diego and biotech company GlySens. "The sensor we developed was designed from the beginning to be a long-term device, and designed to operate for very long periods," says David Gough, the UCSD bioengineer who led the research. In a paper published online today in Science Translational Medicine, Gough and his colleagues show that their sensor can function successfully for over 500 days -- at least in pigs. They hope to begin the first human trial later this year, and are hoping for FDA approval within three years.
Right now, the device transmits its data directly to an external display. But ultimately, the researchers hope that ultimately data from their sensor could be transmitted directly to a patient's smartphone, eliminating the need for any additional hardware. In combination with other technologies in development -- an algorithm-crunching computer that uses glucose data to calculate how much insulin a person needs to control his blood sugar, and an automatic insulin pump to dispense the dose -- the new sensor could help create a low-maintenance system that does the work of a pancreas.
"Continuous glucose monitors are very helpful, but the key thing is that you have to wear them, and that's a big challenge for many people," says Aaron Kowalski, research director for the Juvenile Diabetes Research Foundation's artificial pancreas project. He notes that, because current devices are still slightly conspicuous and require vigilance, teenagers and young adults are less likely to wear them. "So the idea of having a one-year sensor that is implanted is very, very appealing. A device that alleviates some of these real-life issues means you don't have to insert so much, you don't have to see it, and you can walk around and not have all this stuff stuck to you."