Focus on preserving beta cells, understanding disease beginnings
Type 1 Diabetes TrialNet, a newly formed network of 18 clinical centers in the United States, Canada, Europe, and Australia, has launched its first two clinical studies, HHS Secretary Tommy G. Thompson announced today. One study examines the biological basis of type 1 diabetes in at-risk people. The other seeks to preserve insulin-secreting beta cells in patients newly diagnosed with type 1 diabetes. Additional studies will become available as researchers develop protocols to test promising preventions and treatments.
"These new studies will help researchers learn more about preventing and treating type 1 diabetes, which is usually diagnosed in children and young adults but can occur at any age," said Secretary Thompson.
Type 1 diabetes, formerly known as juvenile onset diabetes, develops when the body's immune system mistakenly destroys the insulin-producing beta cells of the pancreas. The hormone insulin is needed to convert glucose into energy. People with this form of diabetes need several insulin injections a day or an insulin pump to survive. However, insulin replacement is not a cure, and most people with type 1 diabetes eventually develop one or more complications of diabetes, including damage to the eyes, nerves, kidneys, and blood vessels. Type 1 diabetes accounts for 5 to 10 percent of all diagnosed cases of diabetes.
About 18.2 million people--6.3 percent of the U.S. population--have diabetes. It is the main cause of kidney failure, limb amputations, and new onset blindness in adults and is a major cause of heart disease and stroke. Type 2 diabetes, which accounts for up to 95 percent of all diabetes cases, is associated with older age, obesity, family history of diabetes, history of gestational diabetes, impaired glucose metabolism, physical inactivity, and race/ethnicity. African Americans, Hispanic/Latino Americans, American Indians, and some Asian Americans and Native Hawaiians or other Pacific Islanders are at particularly high risk for this form of diabetes.
Researchers have made great strides in predicting who is at greatest risk for type 1 diabetes by studying the genetic and immune markers for this disease. Now they're applying this knowledge and a better understanding of the autoimmune process that leads to type 1 diabetes to prevent the disease or stop it from progressing after it is diagnosed.
The natural history study, which is taking place at all 18 TrialNet centers, will probe the causes of type 1 diabetes by examining the immune and metabolic events leading to disease onset. Researchers are looking to screen first-degree relatives ages 1 to 45 and second-degree relatives ages 1 to 20 of those with type 1 diabetes. Screening involves a simple blood test for specific autoantibodies that appear in at-risk people years before diabetes develops. After enrollment in the study, participants will be closely monitored for disease development and may be offered the opportunity to participate in studies that try to arrest the disease process.
Most people with newly diagnosed type 1 diabetes still have some of their beta cells. But even after type 1 diabetes is diagnosed, the immune system keeps destroying these cells, making it harder to control blood glucose. The second TrialNet study seeks to delay or stop the immune destruction of beta cells. It builds on scientific knowledge gained from earlier research on drugs that treat other autoimmune diseases and prevent rejection of transplanted organs.
"If you still have some of your beta cells, you have an easier time controlling your diabetes," said study chair Dr. Jay Skyler. "This study is trying to stop the autoimmune destruction of these cells and keep the disease from getting worse." Much well-designed research has shown that good glucose control slows the development of diabetes complications.
In the second study, patients are randomly assigned to one of three groups receiving mycophenolate mofetil (MMF) alone; MMF plus daclizumab (DZB); or placebo. Both MMF and DZB, which slow immune cell activity, have been approved by the Food and Drug Administration to prevent organ rejection after an organ transplant.
The study is recruiting patients ages 12 to 35 with type 1 diabetes diagnosed in the previous three months. Participants will be closely monitored for any possible side effects of the drugs. The most common side effects are nausea, vomiting, diarrhea, and an increased risk of infection. The MMF/DZB studies are taking place at six TrialNet centers:
- Barbara Davis Center for Childhood Diabetes, Denver, CO
- Indiana University Medical Center, Indianapolis, IN
- Stanford University Medical Center, Stanford, CA
- University of Florida Medical Center, Gainesville, FL
- University of Minnesota Academic Health Center, Minneapolis, MN
- Benaroya Research Institute at Virginia Mason, Seattle, WA.
TrialNet investigators are currently developing protocols for several other agents that have shown promise in earlier studies. Before participating centers can begin enrolling patients, protocols must be approved by local institutional review boards and an NIH Data Safety Monitoring Board, which reviews each study for safety and scientific soundness and monitors its progress.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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