Diabetes Dateline
Spring/Summer 2007

Study Tests Oral Insulin to Prevent Type 1 Diabetes

A network of researchers funded by the National Institutes of Health is testing whether oral insulin can prevent or delay type 1 diabetes in a specific group of people at risk for the disease.

The network, known as Type 1 Diabetes TrialNet, is conducting the study in more than 100 medical centers across the United States, Canada, Europe, and Australia. An earlier trial suggested that oral insulin might delay type 1 diabetes for about 4 years in some people with insulin autoantibodies in their blood. Animal studies have also suggested that oral insulin may prevent type 1 diabetes.

Some scientists think introducing insulin through the digestive tract induces tolerance, or a quieting of the immune system. Insulin taken orally has no side effects because the digestive system breaks it down quickly. To lower blood glucose, people with diabetes must take insulin through an injection or pump.

“Our goal is to prevent type 1 diabetes or to delay it as long as possible,” said TrialNet Study Chair Jay Skyler, M.D., of the University of Miami. “If diabetes can be delayed, even for several years, those at risk will be spared the difficult challenges of controlling glucose and the development of complications for that much longer.”

Natural History Study

First- and second-degree relatives of people with type 1 diabetes who may be at risk are being screened through TrialNet’s natural history study, which examines the immune and metabolic events preceding diabetes symptoms. Screening involves a simple blood test for the autoantibodies that signify diabetes risk. Individuals enrolled in the natural history study are closely monitored for diabetes development and may be eligible to participate in the oral insulin trial or future studies that try to arrest the autoimmune process.

Other TrialNet Studies

Studies for Those Newly Diagnosed

TrialNet studies are also aimed at safely preserving insulin production in people recently diagnosed with type 1 diabetes. In the few months after diagnosis, most people with diabetes still have a supply of functioning beta cells that, with the help of insulin injections, contribute to good blood glucose control. If beta cells could be protected, more people with type 1 diabetes would be able to tightly control their blood glucose, which prevents or delays damage to the eyes, nerves, kidneys, heart, and blood vessels.

One TrialNet study seeks to turn off the immune attack on beta cells with Rituximab, a monoclonal antibody that binds to and temporarily destroys a specific class of immune cells. The Rituximab trial is recruiting participants with type 1 diabetes diagnosed within the previous 3 months. Rituximab is approved by the U.S. Food and Drug Administration (FDA) to treat specific forms of lymphoma and moderate to severe rheumatoid arthritis but not to prevent type 1 diabetes.

Also underway is a study to test whether mycophenolate mofetil (MMF), or MMF plus daclizumab (DZB), can slow or arrest the autoimmunity of type 1 diabetes. The FDA has approved MMF and DZB to prevent organ rejection after transplant. The study has recruited the necessary number of participants.

Newborn Study

The Nutritional Intervention to Prevent Type 1 Diabetes (NIP) Trial is a pilot study of docosahexaenoic acid, an omega-3 fatty acid that may have anti-inflammatory benefits that prevent development of the autoimmunity that leads to type 1 diabetes.

The study is being conducted in babies less than 5 months old who have immediate family members with type 1 diabetes and pregnant mothers in their third trimester whose babies are at risk for type 1 diabetes, either because the mothers or other immediate relatives have the disease.

The National Institute of Diabetes and Digestive and Kidney Diseases is funding the Type 1 Diabetes TrialNet studies, along with the National Institute of Child Health and Human Development, the National Institute of Allergy and Infectious Diseases, the Juvenile Diabetes Research Foundation International, and the American Diabetes Association.

For more information about the TrialNet studies, go to www.DiabetesTrialNet.org or call 1–800–HALT–DM1 (425–8361).

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NIH Publication No. 07–4562
May 2007