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A person with IDDM needs daily injections of the hormone insulin to survive.
Insulin-dependent diabetes (IDDM) is a chronic disease that usually
begins in childhood. It is not the most common form of diabetes--IDDM
accounts for only 5 percent or less of diabetes in this country. Often,
though, IDDM has a much greater impact on a person's life than the more
common adultonset form of diabetes, known as noninsulindependent
The onset of IDDM is usually more swift and severe than that of NIDDM.
A child with IDDM can become sick very quickly. If treatment does not
begin shortly after the first symptoms, the child may need to be
hospitalized. Once the diagnosis is made, a person with IDDM needs daily
injections of the hormone insulin to survive.
Insulin, discovered in the 1920's, has literally made the difference
between life and death for thousands of people with IDDM. Insulin is not
a cure for diabetes, however. Even with careful insulin treatment,
people who have had diabetes for years are at greater than average risk
of developing problems that involve the heart, blood vessels, eyes,
kidneys, and nerves. While most of those with IDDM can lead physically
active and professionally challenging lives, they do not have the luxury
of taking their health for granted.
Research is adding rapidly to our knowledge of diabetes. Besides
searching for a cure, scientists are learning how to help people with
diabetes enjoy a longer life with fewer health problems.
IDDM generally occurs in children and adolescents, though it can appear
at any age.
What Is Diabetes?
Diabetes mellitus impairs the way the body uses digested food for
energy. The sugars and starches (carbohydrates) in the food we eat are
broken down by digestive juices into a simple sugar called glucose.
Glucose circulates in the blood as the major energy source for the body.
For cells in muscles and other tissues to use glucose for energy, the
hormone insulin must be present. Insulin is produced by the pancreas
gland located behind the stomach. When the right amount of insulin is
present, glucose is either used as fuel for energy or stored in the
liver for future use.
In diabetes, however, the pancreas may not make enough insulin, or the
body does not respond to the insulin that is present. Sometimes, a
person with diabetes can have both these problems. As a result, glucose
builds up in the blood and tissues, overflows into the urine, and is
excreted. Thus, the body loses its main source of fuel.
In IDDM the pancreas makes little or no natural insulin, and a person
with IDDM needs daily injections of the hormone to stay alive. IDDM
generally occurs in children and adolescents, though it can appear at
any age. An estimated 300,000 to 500,000 persons in the United States
have IDDM. International statistics on IDDM are unreliable. In general,
however, IDDM is unknown or rare in some ethnic groups, including the
Japanese, Chinese, American Indians, Polynesians, and South African
blacks. On the other hand, Sweden and Finland have very high rates: in
Sweden it is estimated that 3 children in 1,000 have IDDM versus 1.6 in
1,000 in the United States. The reasons for these differences are not
The symptoms of IDDM can be sudden and severe.
NIDDM is the more common form of diabetes. Of the 11 million Americans
who have diabetes, over 95 percent have NIDDM. Fully half of those with
NIDDM don't know they have it. NIDDM usually occurs after age 40. In
NIDDM, the pancreas can produce insulin, but the body does not use it
efficiently. For this reason, most people with NIDDM can control their
diabetes with careful dieting and regular exercise. When diet and
exercise fail to control NIDDM, insulin or oral drugs can be used to
help control the condition.
Effective treatment exists for both IDDM and NIDDM. Even with treatment,
however, both types of diabetes can cause long-term damage to the eyes,
nerves, heart, and kidneys. These complications can lead to blindness,
heart attack, stroke, kidney disease, and serious infections that may
require limb amputation. In IDDM, episodes of very high or low blood
sugar can cause a coma. Careful treatment of diabetes is the most
effective way to minimize the chances of complications.
The symptoms of IDDM can be sudden and severe. They may include frequent
urination, extreme thirst, constant hunger, blurred vision, and extreme
fatigue. Because people with IDDM lack insulin, glucose builds up in the
blood. The kidneys, trying to remove the excess sugar, excrete large
amounts of water and essential body elements, causing frequent urination
Because the body cannot use glucose, its first source of energy, it
turns to stored fat and protein for fuel. As the body uses fat and
protein, weight is lost. Breakdown products of fat collect in blood and
raise its acid content. If levels of these products are high enough, a
critical condition called ketoacidosis can develop, requiring prompt
How Is Diabetes Treated?
A person with IDDM must have insulin injections to survive. Without
insulin, symptoms worsen until the patient loses consciousness and slips
into a coma. With daily insulin shots and a careful diet, however, most
people with IDDM can lead active lives with the same ambitions and
challenges as those without diabetes.
A person with IDDM needs to time meals with insulin doses to keep blood
glucose from getting too high or low.
Treatment for IDDM includes a daily routine of insulin shots or use of
an insulin pump. Following a doctor's instructions, a person with IDDM
buys insulin and syringes and injects himself or herself daily. (The
parent of a young child with IDDM can do this for the child.) More and
more people are also using home blood glucose monitoring devices to
measure their blood glucose during the day. In this way, they can tailor
the insulin dose more closely to changes in their hour-to-hour blood
glucose. Blood glucose monitoring is a more accurate way to monitor
diabetes treatment than urine testing.
Eating the right foods at the right time is an important part of
treatment. A person with IDDM needs to time meals with insulin doses to
keep blood glucose from getting too high or low. The foods you choose
can play a role in controlling blood glucose levels, too. Increasing the
proportion of fiber and complex carbohydrates in your diet and avoiding
refined sugar may aid in reducing drastic changes in blood glucose and
may, in some people, permit lowering of insulin dose. Foods containing
fiber include beans, whole grains, and some fruits, while complex
carbohydrates, or starches, include potatoes, rice, and pasta.
Reducing fats and cholesterol can help reduce the risk of heart disease,
which affects people with diabetes more often than those with normal
Exercise, like diet, can help reduce the risk of heart disease. Being
fit can also bring a sense of well-being and strength that has special
meaning for someone with a chronic illness like diabetes.
Exercise carefully, though. Strenuous exercise increases the muscles'
use of glucose, so it can lower glucose in the blood. At the same time,
exercise also stimulates the body to release glucose and fats for use as
energy. This stimulus can have the effect of raising blood glucose. In
order to exercise safely, you should balance insulin dose, meals, and
the timing of exercise to keep blood glucose levels from getting too
high or too low.
What Causes Diabetes?
No one knows exactly what causes IDDM. What is clear is that the body's
own immune or disease-fighting system for some reason turns against the
body's own tissues. Certain substances formed by the immune system
attack the beta cells of the pancreas, destroying their ability to make
Research shows that most, if not all, people with IDDM may inherit
traits that put them at risk for IDDM. However, not everyone who
inherits these traits develops IDDM. One or more factors in the
environment are believed to trigger the immune system to destroy the
insulin-producing cells. In some cases, the trigger may be a viral
infection. Scientists have, in a few cases, been able to link the onset
of diabetes with a virus. In most cases, however, the trigger for
diabetes is unknown.
Complications of Diabetes
The discovery of insulin in 1921 lengthened the lives of people with
IDDM from weeks or months to decades. In spite of insulin's
life-preserving effects, diabetes remains a deadly disease. This fact is
largely due to the complications of diabetes that develop over many
years of insulin treatment. The complications affect the heart, eyes,
kidneys, and nerves. Much of the damage done to these organs involves
changes in small blood vessels throughout the body. Research is under
way to determine whether very careful control of blood glucose can
prevent or delay diabetic complications. Studies are also under way to
determine why some people with IDDM have trouble with complications
while others live long, relatively healthy lives.
Until the answers to these questions are known, it is wise for people
with IDDM to follow their doctor's advice in controlling blood glucose
and to be aware of the signs and risk factors for complications of
The acute complications of diabetes are the rapid effects that can occur
when blood glucose levels climb too high or fall too low. If an insulin
injection is missed, for example, blood glucose rises, and the person
affected may start to feel weak and hungry, and may urinate frequently.
Since the body can't use glucose for energy, it shifts to using fats and
protein. The products of fat and protein metabolism, substances called
ketones, are toxic when they reach high enough levels. This condition is
called ketoacidosis, and it can cause coma and death if untreated.
Ketoacidosis can develop slowly over several days. The warning symptoms
may include abdominal pain, nausea and vomiting, rapid breathing and a
fruity odor on the person's breath, and drowsiness.
Common symptoms of hypoglycemia include trembling, nervousness,
sweating, hunger, headache, nausea, drowsiness, or a feeling similar to
Glucose can also fall too low in diabetes. Going too long without a
meal, engaging in strenuous exercise, or taking too large a dose of
insulin can cause glucose to drop, a condition called hypoglycemia, or
insulin shock. Common symptoms of hypoglycemia include trembling,
nervousness, sweating, hunger, headache, nausea, drowsiness, or a
feeling similar to drunkenness. Like ketoacidosis, hypoglycemia can
cause coma and death if untreated. A quick, sugar-rich snack or drink
such as orange juice or an injection of glucagon, a hormone that raises
glucose levels, can restore normal glucose levels.
In young people, acute complications pose the greatest threat to
survival for people with IDDM. As people grow older, the long-term
complications become more important. Diabetes can damage many organs
through its effects on blood vessels. How this occurs is not well
understood, but the damage can lead to kidney, heart, eye, and nerve
Kidney disease is the greatest threat to life in adults with IDDM. The
kidneys have a complex network of small blood vessels that filter
impurities from blood for excretion in urine. Diabetes can damage these
small blood vessels so that the kidneys cannot perform their
waste-filtering work. The kidneys are essential to life. People can live
without one kidney, but those who lose both must have their blood
cleansed by a dialysis machine or have a kidney transplant.
Diabetes doubles the risk of heart disease.
High blood pressure can increase the chances that someone will develop
kidney disease, so keeping blood pressure under control is especially
important for someone with IDDM.
Diabetes doubles the risk of heart disease. For reasons not yet well
understood, fat and cholesterol collect more rapidly in the arteries of
people with diabetes than in those without diabetes. These fatty
deposits reduce the supply of blood to the heart and can lead to a heart
Other risk factors for heart disease include hypertension or high blood
pressure, obesity, high amounts of fats and cholesterol in blood, and
cigarette smoking. The more these factors can be eliminated, the more a
person reduces the risk of heart disease.
The major threat to vision from diabetes is diabetic retinopathy.
Retinopathy means disease of the retina, the light-sensing tissue at the
back of the eye. Diabetes causes changes in the tiny vessels that supply
the retina with blood. The blood vessels may swell and leak fluid. When
retinopathy is more severe, new blood vessels may grow from the back of
the eye and bleed into the clear gel, or vitreous, that fills the eye.
A yearly eye examination enables an eye doctor to detect changes before
vision is affected and eye disease becomes harder to treat. Scientists
have found that laser treatment for diabetic retinopathy can help
prevent loss of vision and can, in some cases, restore vision lost as a
result of this disease. A yearly eye exam by an eye doctor is the best
way to make sure that changes in eyesight are diagnosed early and that
effective treatment is carried out when it can be most helpful.
A yearly eye exam by an eye doctor is the best way to make sure that
changes in eyesight are diagnosed early.
Diabetic Nerve Disease
Nerve damage from diabetes (diabetic neuropathy) can dull sensation in
the feet, legs, and fingertips. When this happens, bruises or sores may
go unnoticed until they become open or infected. Reduced blood flow
caused by diabetes' effects on the blood vessels (peripheral vascular
disease) can slow healing of foot sores. Because of diabetic neuropathy
and peripheral vascular disease, people with diabetes are at increased
risk of needing amputation when leg and foot sores become gravely
Severe pain in the legs and feet sometimes comes with diabetic
neuropathy. Pain-killing drugs and sometimes antidepressant drugs are
used to treat painful neuropathy. In most cases, the pain subsides on
its own with time.
Diabetic neuropathy can also affect body functions such as digestion. A
doctor may prescribe drugs to relieve these symptoms. In addition,
diabetes can, over time, affect the nerves that control erection in men.
A doctor can find out whether impotence is the result of emotional or
physical changes, such as diabetes, and then suggest treatment or
A mother's careful control of her glucose is essential to the health and
life of her baby.
With insulin treatment available, IDDM no longer poses the threat it
once did to the health of the pregnant mother. The infant of a mother
with IDDM does, however, have a higher than average risk of birth
defects, stillbirth, respiratory distress, and other problems at birth.
A mother's careful control of her glucose is essential to the health and
life of her baby. With careful diabetes control, beginning before
conception if possible, it is likely that the child will be healthy in
Does Diabetes Run in Families?
A susceptibility to diabetes can be inherited. The brothers and sisters
of a child with diabetes have a higher than average risk of developing
IDDM. However, their risk remains small--only about 1 in 20 children
with a diabetic sibling will develop IDDM. In fact, an identical twin of
a child with IDDM has less than a 50 percent chance of developing the
disease. Scientists are still doing research to determine how and why
certain factors--both inherited and environmental--sometimes lead to
Illness and Surgery
Illness, such as influenza, and stress, such as personal losses or
conflicts, can affect the body's use of glucose. During times of illness
and stress, a person needs to be even more careful about keeping glucose
Surgery also places unusual stress on the body. Surgical teams take
special precautions when doing surgery on a person with IDDM. The best
way to ensure that doctors are aware of a patient's diabetes is to tell
During times of illness and stress, a person needs to be even more
careful about keeping glucose in control.
Research in Diabetes
Diabetes research is the best hope that one day a means of curing and
possibly preventing diabetes will be found. In the last 10 years,
diabetes researchers have made great strides in understanding this
disease. Critical to this effort has been the technology developed in
genetics, microbiology, immunology, and other disciplines that have
given diabetes researchers the tools they need to examine at the cell
level what happens in diabetes.
The National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK) was established by Congress in 1950 as an institute of the
National Institutes of Health (NIH), whose mission is to improve human
health through biomedical research. The NIH is the research arm of the
Public Health Service under the U.S. Department of Health and Human
The NIDDK conducts and supports a variety of research in diabetes and
its complications. In the past several years, scientists have identified
the genetic factors that are associated with both IDDM and NIDDM. A
major goal of future research will be to clarify how inherited factors
affect the immune or disease-fighting system to result in IDDM. Already,
scientists have identified immune factors circulating in blood that
indicate increased risk of developing IDDM. This information may lead to
early identification of IDDM cases and will help pave the way to
understanding why the immune system goes awry in IDDM.
Scientists also have a better understanding of how insulin works in
glucose metabolism. For example, groups of researchers at Memorial
Sloan-Kettering Cancer Center, New York; the University of California,
San Francisco; Mr. Zion Hospital and Medical Center, San Francisco; and
Stanford University, Stanford, California, recently cloned and analyzed
the structure of the insulin receptor, a molecule on cell surfaces to
which insulin must attach in order to act. Defects in receptor function
have been linked to abnormalities in glucose metabolism.
Human insulin made by recombinant DNA techniques is commercially
available, as are externally worn pumps that can be programmed by the
wearer to deliver insulin through a catheter in the abdomen. Research is
continuing on internally implantable pumps, and clinical trials on at
least one such pump have been undertaken.
New treatments are being developed for the complications of diabetes.
Laser photocoagulation therapy has been shown to reduce the risk of
blindness in people with diabetic retinopathy. Preventive measures and
medications are available to help control high blood pressure, to avoid
lower extremity amputations, and to reduce the risk of tooth loss from
periodontal (gum)disease. Understanding how maternal diabetes can affect
the unborn child is increasing, and with it, strategies to improve the
chances that such a child will be born normal and healthy.
Research on transplantation of the insulinproducing cells of the
pancreas is ongoing. The aim of this research is to provide a means of
transplanting insulin-producing cells into someone with diabetes without
the need to suppress the immune system to prevent rejection. If
successful, the procedure would eliminate the need for daily injections
Clinical trials are one means to test new approaches to treatment that
emerge from basic research. In a clinical trial, new and existing
treatments are compared with each other or with no treatment.
The NIDDK is supporting and planning clinical trials that are designed
to weigh the benefits and risks of various approaches to treatment of
diabetes and its complications. For information about NIDDK-supported
clinical trials, contact the National Institute of Diabetes and
Digestive and Kidney Diseases, National Institutes of Health, Building
31, Room 9A04, Bethesda, Maryland 20892.
The Diabetes Dictionary
Available from the National Diabetes Information Clearinghouse,
Box NDIC, Bethesda, Maryland 20892, telephone (301) 468-2162.
Diabetes Mellitus: Theory and Practice, Ellenberg, M., and
Rifkin, H., Editors.
This book is an example of medical textbooks that provide an
overview of diabetes, its symptoms, epidemiology, and
This text is revised periodically and published by Medical Examination
Publishing Company. It is written for readers with a medical background
and is available in medical libraries and possibly university libraries
or through interlibrary loan at a public library.
Diabetes and Your Eyes
Available from the National Eye Institute,
National Institutes of Health, Building 31,
Room 6A32, Bethesda, Maryland 20892,
telephone (301) 496-5248.
The American Diabetes Association, listed below, has a
variety of periodicals and publications, at both a lay and technical
level, on various aspects of diabetes.
American Diabetes Association
National Service Center
1660 Duke Street
Alexandria, Virginia 22314
Juvenile Diabetes Foundation, International
432 Park Avenue, South, 16th Floor
New York, New York 10016
National Diabetes Information Clearinghouse
Bethesda, Maryland 20892
Information provided by NIH.