Type
I Diabetes and Oral Insulin Study Underway
Researchers have begun a clinical study of oral insulin
to prevent or delay type 1 diabetes in at-risk persons, according to scientists
at the National Institutes of Health (NIH).
The new study is underway in more than 100 medical centers
across the US, Canada, Europe, and Australia.
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 research.
“Our goal is to prevent type 1 diabetes or to delay
it as long as possible,” says TrialNet study
chair Dr. Jay Skyler, 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,” says Dr.
Skyler.
About 5 percent 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 occur in children and young adults
but is also diagnosed in older persons.
People with type 1 diabetes 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 people with type 1 diabetes and their families.
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 five 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.
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.
Always consult your physician for more information.
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Type 1 diabetes may also be known by a variety of other
names, including the following:
- insulin-dependent diabetes mellitus (IDDM)
- juvenile diabetes
- brittle diabetes
- sugar diabetes
There are two forms of type 1 diabetes:
- idiopathic type 1 diabetes - refers to rare forms of the disease with
no known cause.
- immune-mediated diabetes - an autoimmune disorder in which the body's
immune system destroys, or attempts to destroy, the cells in the pancreas
that produce insulin.
Immune-mediated diabetes is the most common form of type
1 diabetes, and the one generally referred to as type 1 diabetes. The information
following refers to this form of type 1 diabetes.
Type 1 diabetes accounts for 5 percent to 10 percent of
all diagnosed cases of diabetes in the US.
Type 1 diabetes usually develops in children or young
adults, but can start at any age.
The cause of type 1 diabetes is unknown, but it is believed
that genetic and environmental factors (possibly viruses) may be involved.
The body's immune system attacks and destroys the insulin
producing cells in the pancreas. Insulin allows glucose to enter the cells
of the body to provide energy.
When glucose cannot enter the cells, it builds up in the
blood and the body's cells literally starve to death.
People with type 1 diabetes must take daily insulin injections
and regularly monitor their blood sugar levels.
Type 1 diabetes often appears suddenly.
The following are the most common symptoms of type 1 diabetes.
However, each individual may experience symptoms differently. Symptoms may
include:
- high levels of sugar in the blood when tested
- high levels of sugar in the urine when tested
- unusual thirst
- frequent urination
- extreme hunger but loss of weight
- blurred vision
- nausea and vomiting
- extreme weakness and fatigue
- irritability and mood changes
In children, symptoms may be similar to those of having
the flu.
The symptoms of type 1 diabetes may resemble other conditions
or medical problems. Always consult your physician for a diagnosis.
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