Diabetes Overview - What Is Diabetes? What
Are the Different Types of Diabetes?
Each year, about 798,000 people are diagnosed
with diabetes. "
What Is Diabetes?
Diabetes is a disorder of metabolism--the way our bodies use
digested food for growth and energy. Most of the food we eat is
broken down by the digestive juices into a simple sugar called
glucose. Glucose is the main source of fuel for the body.
After digestion, the glucose passes into our bloodstream where
it is available for body cells to use for growth and energy. For
the glucose to get into the cells, insulin must be present. Insulin
is a hormone produced by the pancreas, a large gland behind the
When we eat, the pancreas is supposed to automatically produce
the right amount of insulin to move the glucose from our blood
into our cells. In people with diabetes, however, the pancreas
either produces little or no insulin, or the body cells do not
respond to the insulin that is produced. As a result, glucose
builds up in the blood, overflows into the urine, and passes out
of the body. Thus, the body loses its main source of fuel even
though the blood contains large amounts of glucose.
What Are the Different Types of Diabetes? The three main types
of diabetes are:
Type 1 diabetes
Type 2 diabetes
Type 1 diabetes
Type 1 diabetes (once known as insulin-dependent diabetes mellitus
or juvenile diabetes) is considered an autoimmune disease. An
autoimmune disease results when the body's system for fighting
infection (the immune system) turns against a part of the body.
In diabetes, the immune system attacks the insulin-producing beta
cells in the pancreas and destroys them. The pancreas then produces
little or no insulin.
Someone with type 1 diabetes needs daily injections of insulin
to live. At present, scientists do not know exactly what causes
the body's immune system to attack the beta cells, but they believe
that both genetic factors and viruses are involved. Type 1 diabetes
accounts for about 5 to 10 percent of diagnosed diabetes in the
Type 1 diabetes develops most often in children and young adults,
but the disorder can appear at any age. Symptoms of type 1 diabetes
usually develop over a short period, although beta cell destruction
can begin years earlier.
Symptoms include increased thirst and urination, constant hunger,
weight loss, blurred vision, and extreme tiredness. If not diagnosed
and treated with insulin, a person can lapse into a life-threatening
Type 2 diabetes
The most common form of diabetes is type 2 diabetes (once known
as noninsulin-dependent diabetes mellitus or NIDDM). About 90
to 95 percent of people with diabetes have type 2 diabetes. This
form of diabetes usually develops in adults over the age of 40
and is most common among adults over age 55. About 80 percent
of people with type 2 diabetes are overweight.
In type 2 diabetes, the pancreas usually produces insulin, but
for some reason, the body cannot use the insulin effectively.
The end result is the same as for type 1 diabetes--an unhealthy
buildup of glucose in the blood and an inability of the body to
make efficient use of its main source of fuel.
The symptoms of type 2 diabetes develop gradually and are not
as noticeable as in type 1 diabetes. Symptoms include feeling
tired or ill, frequent urination (especially at night), unusual
thirst, weight loss, blurred vision, frequent infections, and
slow healing of sores.
Gestational diabetes develops or is discovered during pregnancy.
This type usually disappears when the pregnancy is over, but women
who have had gestational diabetes have a greater risk of developing
type 2 diabetes later in their lives.
*What Is the Scope and Impact of Diabetes?
Diabetes is widely recognized as one of the leading causes of
death and disability in the United States. According to death
certificate data, diabetes contributed to the deaths of more than
193,140 persons in 1996.
Diabetes is associated with long-term complications that affect
almost every major part of the body. It contributes to blindness,
heart disease, strokes, kidney failure, amputations, and nerve
damage. Uncontrolled diabetes can complicate pregnancy, and birth
defects are more common in babies born to women with diabetes.
Diabetes cost the United States $98 billion in 1997. Indirect
costs, including disability payments, time lost from work, and
premature death, totaled $54 billion; medical costs for diabetes
care, including hospitalizations, medical care, and treatment
supplies, totaled $44 billion.
*Who Gets Diabetes?
Diabetes is not contagious. People cannot "catch"
it from each other. However, certain factors can increase one's
risk of developing diabetes. People who have family members with
diabetes (especially type 2 diabetes ), who are overweight, or
who are African American, Hispanic, or Native American are all
at greater risk of developing diabetes.
Type 1 diabetes occurs equally among males and females, but
is more common in whites than in nonwhites. Data from the World
Health Organization's Multinational Project for Childhood Diabetes
indicate that type 1 diabetes is rare in most Asian, African,
and American Indian populations. On the other hand, some northern
European countries, including Finland and Sweden, have high rates
of type 1 diabetes. The reasons for these differences are not
Type 2 diabetes is more common in older people, especially older
women who are overweight, and occurs more often among African
Americans, Hispanics, and American Indians. Compared with non-Hispanic
whites, diabetes rates are about 60 percent higher in African
Americans and 110 to 120 percent higher in Mexican Americans and
Puerto Ricans. American Indians have the highest rates of diabetes
in the world. Among Pima Indians living in the United States,
for example, half of all adults have type 2 diabetes. The prevalence
of diabetes is likely to increase because older people, Hispanics,
and other minority groups make up the fastest growing segments
of the U.S. population.
*How Is Diabetes Managed?
Before the discovery of insulin in 1921, all people with type
1 diabetes died within a few years after the appearance of the
disease. Although insulin is not considered a cure for diabetes,
its discovery was the first major breakthrough in diabetes treatment.
Today, daily injections of insulin are the basic therapy for
type 1 diabetes. Insulin injections must be balanced with meals
and daily activities, and glucose levels must be closely monitored
through frequent blood sugar testing.
Diet, exercise, and blood testing for glucose are also the basis
for management of type 2 diabetes. In addition, some people with
type 2 diabetes take oral drugs or insulin to lower their blood
People with diabetes must take responsibility for their day-to-day
care. Much of the daily care involves trying to keep blood sugar
levels from going too low or too high. When blood sugar levels
drop too low--a condition known as hypoglycemia--a person can
become nervous, shaky, and confused. Judgment can be impaired.
Eventually, the person could pass out. The treatment for low blood
sugar is to eat or drink something with sugar in it.
On the other hand, a person can become very ill if blood sugar
levels rise too high, a condition known as hyperglycemia. Hypoglycemia
and hyperglycemia, which can occur in people with type 1 diabetes
or type 2 diabetes, are both potentially life-threatening emergencies.
People with diabetes should be treated by a doctor who monitors
their diabetes control and checks for complications. Doctors who
specialize in diabetes are called endocrinologists or diabetologists.
In addition, people with diabetes often see ophthalmologists for
eye examinations, podiatrists for routine foot care, dietitians
for help in planning meals, and diabetes educators for instruction
in day-to-day care.
The goal of diabetes management is to keep blood glucose levels
as close to the normal (nondiabetic) range as safely possible.
A recent Government study, sponsored by the National Institute
of Diabetes and Digestive and Kidney Diseases (NIDDK), proved
that keeping blood sugar levels as close to normal as safely possible
reduces the risk of developing major complications of diabetes.
The 10-year study, called the Diabetes Control and Complications
Trial (DCCT), was completed in 1993 and included 1,441 people
with type 1 diabetes. The study compared the effect of two treatment
approaches--intensive management and standard management--on the
development and progression of eye, kidney, and nerve complications
of diabetes. Researchers found that study participants who maintained
lower levels of blood glucose through intensive management had
significantly lower rates of these complications.
Researchers believe that DCCT findings have important implications
for the treatment of type 2 diabetes, as well as type 1 diabetes.
*What Is the Status of Diabetes Research?
NIDDK supports basic and clinical research in its own laboratories
and in research centers and hospitals throughout the United States.
It also gathers and analyzes statistics about diabetes. Other
institutes at the National Institutes of Health also carry out
research on diabetes-related eye diseases, heart and vascular
complications, pregnancy, and dental problems.
Other Government agencies that sponsor diabetes programs are
the Centers for Disease Control and Prevention, the Indian Health
Service, the Health Resources and Services Administration, the
Bureau of Veterans Affairs, and the Department of Defense.
Many organizations outside of the Government support diabetes
research and education activities. These organizations include
the American Diabetes Association, the Juvenile Diabetes Foundation
International, and the American Association of Diabetes Educators.
In recent years, advances in diabetes research have led to better
ways to manage diabetes and treat its complications. Major advances
New forms of purified insulin, such as human insulin produced
through genetic engineering.
Better ways for doctors to monitor blood glucose levels and
for people with diabetes to test their own blood glucose levels
Development of external and implantable insulin pumps that deliver
appropriate amounts of insulin, replacing daily injections.
Laser treatment for diabetic eye disease, reducing the risk
Successful transplantation of kidneys in people whose own kidneys
fail because of diabetes.
Better ways of managing diabetic pregnancies, improving chances
of successful outcomes.
New drugs to treat type 2 diabetes and better ways to manage
this form of diabetes through weight control.
Evidence that intensive management of blood glucose reduces
and may prevent development of microvascular complications of
Demonstration that antihypertensive drugs called ACE-inhibitors
prevent or delay kidney failure in people with diabetes.
*What Will the Future Bring?
In the future, it may be possible to administer insulin through
nasal sprays or in the form of a pill or patch. Devices that can
"read" blood glucose levels without having to prick
a finger to get a blood sample are also being developed.
Researchers continue to search for the cause or causes of diabetes
and ways to prevent and cure the disorder. Scientists are looking
for genes that may be involved in type 2 diabetes and type 1 diabetes.
Some genetic markers for type 1 diabetes have been identified,
and it is now possible to screen relatives of people with type
1 diabetes to see if they are at risk for diabetes.
The new Diabetes Prevention Trial-- type 1 diabetes, sponsored
by NIDDK, identifies relatives at risk for developing type 1 diabetes
and treats them with low doses of insulin or with oral insulin-like
agents in the hope of preventing type 1 diabetes. Similar research
is carried out at other medical centers throughout the world.
Transplantation of the pancreas or insulin-producing beta cells
offers the best hope of cure for people with type 1 diabetes.
Some pancreas transplants have been successful. However, people
who have transplants must take powerful drugs to prevent rejection
of the transplanted organ. These drugs are costly and may eventually
cause serious health problems.
Scientists are working to develop less harmful drugs and better
methods of transplanting pancreatic tissue to prevent rejection
by the body. Using techniques of bioengineering, researchers are
also trying to create artificial islet cells that secrete insulin
in response to increased sugar levels in the blood.
For type 2 diabetes, the focus is on ways to prevent diabetes.
Preventive approaches include identifying people at high risk
for the disorder and encouraging them to lose weight, exercise
more, and follow a healthy diet. The Diabetes Prevention Program,
another new NIDDK project, will focus on preventing the disorder
in high-risk populations.
*Where Is More Information Available?
For more information about type 1 diabetes, type 2 diabetes,
and gestational diabetes, as well as diabetes research, statistics,
and education, contact:
National Diabetes Information Clearinghouse
1 Information Way
Bethesda, MD 20892-3560
The following organizations also distribute materials and support
programs for people with diabetes and their families and friends:
American Association of Diabetes Educators
100 West Monroe Street, 4th Floor
Chicago, IL 60603
(800) 338-3633 or (312) 424-2426
American Diabetes Association
ADA National Service Center
1660 Duke Street
Alexandria, VA 22314
Juvenile Diabetes Foundation International
120 Wall Street, 19th Floor
New York, NY 10005
Points to Remember What Is Diabetes?
A disorder of metabolism--the way the body digests food for
energy and growth.
What Are the Different Types of Diabetes?
Type 1 diabetes
Type 2 diabetes
What Is the Scope and Impact of Diabetes?
Affects 16 million people
A leading cause of death and disability
Costs $98 billion per year.
Who Gets Diabetes?
People of any age
More common in older people, African Americans, Hispanics, and
National Diabetes Information Clearinghouse
1 Information Way
Bethesda, MD 20892-3560
The National Diabetes Information Clearinghouse (NDIC) is a
service of the National Institute of Diabetes and Digestive and
Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes
of Health under the U.S. Department of Health and Human Services.
Established in 1978, the clearinghouse provides information about
diabetes to people with diabetes and their families, health care
professionals, and the public. NDIC answers inquiries; develops,
reviews, and distributes publications; and works closely with
professional and patient organizations and government agencies
to coordinate resources about diabetes.
Source: National Diabetes Information Clearinghouse - June 2000
Association of Diabetes Educators