Study Tests Oral Insulin to Prevent Type 1 Diabetes
Researchers have begun a clinical study of oral insulin to prevent
or delay type 1 diabetes in at-risk people, the National Institutes
of Health (NIH) announced today. Type 1 Diabetes TrialNet, an NIH-funded
network of researchers dedicated to the understanding, prevention,
and early treatment of type 1 diabetes, is conducting the study
in more than 100 medical centers across the United States, Canada,
Europe, and Australia.
“Our goal is to prevent type 1 diabetes or to delay it as long
as possible. 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,” said
TrialNet study chair Jay Skyler, M.D., of the University of Miami.
In the study, researchers are testing whether an insulin capsule
taken by mouth once a day can prevent or delay diabetes in a specific
group of people at risk for type 1 diabetes. An earlier trial suggested
that oral insulin might delay type 1 diabetes for about four years
in some people with autoantibodies to insulin in their blood. Animal
studies have also suggested that insulin taken orally may prevent
type 1 diabetes. Some scientists think that introducing insulin
via 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,
insulin must be injected or administered by an insulin pump.
In type 1 diabetes, a person’s own immune cells destroy the beta
cells of the pancreas. Beta cells sense blood glucose and produce
the hormone insulin, which regulates glucose and converts it to
energy. The immune attack on beta cells begins well before a person
develops diabetes and continues long after the disease is diagnosed.
In the early stages of autoimmunity, up to 10 years before diabetes
is diagnosed, autoantibodies may appear in the blood. These autoantibodies
to glutamate decarboxylase (GAD), IA-2, and to insulin itself indicate
a greater risk for developing type 1 diabetes. For a person with
high-risk genes and all three antibodies, the risk of developing
diabetes in the next 5 years is greater than 50 percent.
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 is examining the immune and metabolic events
that precede 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.
Studies for the 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 patients still have a supply of functioning
beta cells that, with the help of insulin injections, contribute
to good control of blood glucose. If beta cells can be protected,
more patients 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 patients with type 1 diabetes diagnosed within the
previous 3 months. Rituximab is approved by the Food and Drug Administration
(FDA) to treat specific forms of lymphoma and moderate to severe
rheumatoid arthritis. It is not approved for the prevention of
type 1 diabetes.
Also under way is a study testing whether mycophenolate mofetil
(MMF) or MMF plus daclizumab (DZB), drugs approved by FDA to prevent
rejection after an organ transplant, can slow or arrest the autoimmunity
of type 1 diabetes. This study has recruited the needed number
of patients.
Study for Newborns at Risk for Type 1 Diabetes
The Nutritional Intervention to Prevent Type 1 Diabetes (NIP)
Trial is a pilot study of docosahexaenoic acid (DHA), an omega-3
fatty acid that may have anti-inflammatory benefits that prevent
development of the autoimmunity that leads to type 1 diabetes. The
NIP 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 mother has type
1 diabetes herself or other immediate relatives have the disease.
About 5 to 10 percent of the nearly 21 million people with diabetes
have type 1, formerly known as juvenile onset diabetes or insulin-dependent
diabetes. Type 1 diabetes tends to arise in children and young
adults but is also diagnosed in older people. Patients need three
or more insulin injections a day or treatment with an insulin pump
to maintain blood glucose control. To prevent complications, they
must regularly monitor their blood glucose, striving for a range
that is as close to normal as possible. The constant challenge
of managing the disease poses an enormous burden on patients and
their families.
The Type 1 Diabetes TrialNet studies are funded by the National
Institute of Diabetes and Digestive and Kidney Diseases, the National
Institute of Child Health and Human Development, and the National
Institute of Allergy and Infectious Diseases within the NIH. The
Juvenile Diabetes Research Foundation International and the American
Diabetes Association also support the initiative.
For more information about TrialNet studies, see www.DiabetesTrialNet.org or
call 1-800-HALT-DM1 (1-800-425-8361).
The NIDDK, a component of the NIH, conducts and supports research
in diabetes and other endocrine and metabolic diseases; digestive
diseases, nutrition, and obesity; and kidney, urologic and hematologic
diseases. Spanning the full spectrum of medicine and afflicting
people of all ages and ethnic groups, these diseases encompass
some of the most common, severe, and disabling conditions affecting
Americans. For more information about NIDDK and its programs,
see www.niddk.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov. |