VOICE ONE:
This is Steve Ember.
VOICE TWO:
And this is Bob Doughty with Science in the News, a VOA Special
English program about recent developments in science. Today,
we tell about the disease diabetes.
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VOICE ONE:
The World Health Organization estimates that as many as one-hundred-twenty-million
people have the disease diabetes. Diabetes is the name for several
diseases with one thing in common: there is too much glucose,
or sugar, in the blood. The disease develops when the body does
not produce enough insulin or produces no insulin. Or the disease
develops when the body cannot use insulin.
Insulin is a hormone that is necessary to change sugar, carbohydrates
and other food into energy. In healthy people, the body changes
food into a sugar, called glucose. Glucose is the source of
fuel for the body. When food is changed into glucose, it enters
the bloodstream and is taken to all parts of the body to feed
muscles, organs, and tissue.
VOICE TWO:
When the body senses that there is too much glucose in the
blood, it sends a signal to the pancreas. The pancreas is the
organ that produces insulin. The pancreas sends insulin into
the bloodstream. The insulin lowers the level of blood sugar
by letting it enter cells. Insulin helps muscles, organs and
tissues take glucose and change it into energy.
That is how the body operates normally, in most people. Diabetes
is present when too much glucose remains in the bloodstream
and does not enter cells. If the amount of glucose in the blood
remains too high, the body begins showing signs of diabetes.
Over time, the disease can cause blindness, kidney disease,
and nerve damage.
High glucose levels in the blood also can lead to strokes and
heart disease. Blood circulation also is affected, especially
in the legs. Often, victims of diabetes must have a foot or
even a leg removed because of blood circulation problems linked
to the disease.
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VOICE ONE:
There are two main kinds of diabetes, Type One and Type Two.
Between five and ten percent of those suffering from diabetes
have Type One. It usually begins before the age of thirty in
people who are thin.
It is most commonly found in children under the age of sixteen.
It is caused by the body¡¯s defense system. The bodies
of Type One diabetes victims produce a substance that attacks
and kills some cells in the pancreas, blocking the production
of insulin. These cells are called islet (EYE-lit) cells. Scientists
are not sure why this happens. They believe there may be a number
of causes.
They include viruses, the presence of insect-killing pesticides
in the environment or molecules known as free radicals. Free
radicals are produced as part of normal chemical processes in
the body. In people with diabetes, too many of these free radicals
are present in the body. Scientists are not sure which of these
causes is the most important to the development of Type One
diabetes.
VOICE TWO:
People suffering from Type One diabetes must carefully control
their diets. And they must exercise often. People with this
kind of diabetes almost always require insulin injections. Patients
must always know their blood sugar levels. When the level of
glucose in the blood is too high, they must inject insulin into
their bodies to reduce the amount of glucose.
The patients must inject insulin every day, often several times
a day. In most developed countries, insulin is easy to get and
does not cost much money. However, doctors believe that these
injections can cause long-term problems. They believe that the
injections cause levels of glucose to change often.
Scientists believe that many quick changes in glucose levels
can, over time, result in damage to the body. This damage can
be blindness, kidney failure, heart disease, or poor blood flow
in the body.
VOICE ONE:
Type One diabetes also is known as juvenile onset diabetes,
because it usually starts in children or young people. Scientists
believe it is the form of the disease that they will most likely
be able to cure some day. Among the treatments being studied
is a vaccine to prevent the disease. A vaccine is injected into
the body or taken by mouth in the form of a pill.
Another possible treatment for Type One diabetes is placing
new islet cells into the pancreas to help it make insulin. Doctors
have been transplanting islet cells into diabetes patients for
several years. However, these healthy islet cells have failed
to permanently replace the need for insulin injections.
Scientists also are studying special cells called stem cells
to treat the disease. Stem cells develop into all the different
kinds of cells in the body. Scientists believe that stem cells
from unborn babies could be used to treat diabetes and other
diseases. However, it would be a long time before such treatment
is possible.
VOICE TWO:
While some scientists continue to seek ways to cure Type One
diabetes, others are searching for easier ways to get insulin
into the body. New devices are being developed that could replace
injections. One device being tested is an inhaler.
This device would permit patients to breathe insulin into their
bodies. The insulin is in the form of a powder, like dust. When
the insulin reaches the lungs, it quickly moves into the bloodstream
to reduce glucose levels.
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VOICE ONE:
Type Two diabetes generally is found in people more than forty
years old. Most of these people are too fat. Their bodies can
not produce enough insulin to reduce the levels of glucose in
their blood. Or, their bodies do not react correctly to the
action of insulin.
Type Two diabetes is more complex than Type One. Experts say
Type Two diabetes is really a group of diseases, with many possible
causes. Scientists see little hope in developing a cure for
this kind of diabetes. Instead, they are searching for better
ways to control it.
Many people suffering from the disease can control it with
exercise and by carefully controlling their diet. Also, many
of them do not need to inject insulin into their bodies. Type
Two diabetes is sometimes called non-insulin dependent. Still,
patients often need drugs to treat the disease.
VOICE TWO:
There are a number of drugs that can be used. However, many
of them can cause other problems. One of the drugs is called
sulfonylurea. It has been used for many years to help the pancreas
make more insulin. But after several years, the drug loses its
effects on the pancreas. Also, it can cause patients to gain
weight.
The drug metformin appears to be more effective. It lowers
the amounts of glucose in the blood. It does this by helping
the body make better use of its own natural insulin. It does
not cause weight gain. However, metformin can be dangerous for
people with damaged kidneys. It should not be used by people
who drink large amounts of alcohol, or those with kidney, liver
or heart problems.
VOICE ONE:
Genes seem to be more important in the development of Type
Two diabetes than in Type One. About ninety percent of those
with Type Two diabetes have parents and ancestors who also had
the disease. In recent years, scientists have found several
genes that may be linked to Type Two diabetes. Some of these
genes also are linked to extreme overweight, known as obesity.
About eighty to ninety percent of people with Type Two diabetes
are obese. Often doctors do not discover that patients have
diabetes until one of the disease¡¯s serious results
is found. For example, a doctor examines a patient suffering
several health problems.
The doctor carries out tests and finds the problems are the
results of poor kidney performance. Tests then show the patient
is suffering from diabetes, which can cause kidney problems
and even failure.
VOICE TWO:
Although great progress has been made in the treatment of diabetes,
it is still widespread and threatens the health of millions
of people. Scientists hope that their research will lead to
a cure for Type One diabetes. And they hope they can find new
ways to improve treatment of Type Two diabetes. In future programs
we will discuss new developments in diabetes research as they
are reported.
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VOICE ONE:
This Science in the News program was written by Oliver Chanler.
This is Steve Ember.
VOICE TWO:
And this is Bob Doughty. Join us again next week for more news
about science in Special English on the Voice of America.
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This Science Report is published courtesy
of VOAnews.com
