Seventy out of every
1,000 Americans reading this article have a disease that will, on average,
shorten their lives by about 20 years. More than 20 of these 70 people
are not even aware they are ill. The disease in question is diabetes,
and it consumes one out of every ten health care dollars spent in the
U.S. However, with proper treatment and lifestyle changes, many of its
devastating complications can be prevented or delayed.
Diabetes is a chronic disease that impairs the body’s ability to
use food properly. As food is digested, its components are converted into
the simple sugar glucose, which is absorbed into the blood through the
small intestine. The body relies on glucose as its basic fuel, but it
first needs to move the glucose from the bloodstream into the muscles
and organs where it’s needed. This transfer requires a hormone called
insulin, produced by the pancreas. The body continually monitors blood
sugar levels; in healthy people, it corrects with more insulin if the
blood sugar gets too high, with less if it gets too low.
When people have diabetes, either their pancreatic cells don’t produce
enough insulin or their bodies are not able to efficiently use the insulin
that is made. Glucose gets trapped in the bloodstream and spills into
the urine. At the same time the muscles and organs are starved for energy,
the blood’s high sugar content damages the cells of many organs
it flows through. If the levels are very high, they can cause coma or
Over time, diabetes causes destruction throughout the body. It affects
the blood vessels and the heart, increasing the risk of heart disease
or stroke by up to four times; two-thirds of people who have diabetes
die from these complications. Many people have already damaged the blood
vessels in their eyes by the time they are diagnosed, and 90 percent of
them have damage after 15 years with the illness; these changes cause
almost 40,000 cases of blindness each year, making diabetes the leading
cause of adult-onset blindness in North America. Kidney disease is also
a major complication; about 30 percent of new dialysis patients have diabetes-induced
kidney failure. About 60 to 70 percent of people with diabetes have nervous
system damage, causing problems like numbness or pain in the hands and
feet or slowed digestion of food in the stomach. Amputations occur 10
times more frequently in people with diabetes than in people without diabetes,
and the illness also impairs the immune system, making people more susceptible
to serious infection.
While there is not yet a cure for diabetes, it can be controlled. The
main goal of all treatment is to control blood sugar levels, but the method
varies depending on the type of diabetes a person has.
Type 1 Diabetes
The most severe form of diabetes is type 1, previously known as juvenile
diabetes because it is usually develops during childhood or young adulthood.
Type 1 accounts for 5 to 10 percent of all diagnosed cases of diabetes
and affects about one in every 400 to 600 children and adolescents. In
this form of the illness, the pancreas produces little or no insulin.
Although the causes are not entirely known, scientists believe the body’s
immune system mistakenly attacks and destroys the insulin-producing cells
in the pancreas.
Viruses may trigger the onset of type 1 diabetes because they contain
proteins that look very similar to proteins found in the pancreas’
insulin-producing beta cells. Studies have also linked type 1 diabetes
to the rat poison pyriminil as well as the prescription drugs pentamidine,
used to treat a severe form of pneumonia, and L-asparaginase, a cancer
treatment. Genetic factors are probably involved in making some people
more susceptible, as type 1 diabetes tends to run in families.
The early symptoms of type 1 diabetes are frequent urination in large
quantities, excessive thirst, extreme hunger all the time, sudden weight
loss for no apparent reason, weakness, drowsiness, sudden vision changes,
nausea and vomiting. Before the discovery of insulin in 1921, these symptoms
often led to coma and death within a few weeks.
People with type 1 diabetes must check their blood sugar and take injections
of insulin several times every day to prevent life-threatening consequences
from blood sugar that is too high or too low. Additionally, lifestyle
factors such as diet and fitness are important for maintaining health
Type 2 Diabetes
More than 90 percent of people with diabetes have type 2, in which the
pancreas still produces insulin but the cells of the body are not able
to use it properly (a condition called insulin resistance). As the body’s
need for insulin rises, gradually the overtaxed pancreas loses the ability
to produce it. Type 2 was previously called adult-onset diabetes because
it occurs more frequently in later life, although as childhood obesity
increases it is beginning to appear in some children and adolescents.
Several risk factors increase the chance that a person will develop type
2 diabetes. Lifestyle factors such as physical inactivity and obesity
increase the risk for type 2 diabetes by more than tenfold. Being heavy
around the belly (apple-shaped) appears to be worse than being heavy in
the thighs (pear-shaped). Type 2 disease also runs in families, suggesting
a strong genetic component. Certain racial and ethnic groups are affected
more frequently; in the U.S., African-Americans, Latinos, American Indians,
Alaskan Natives, Asian Americans and Pacific Islanders are around twice
as likely as Caucasians to develop the illness. Additionally, age plays
a role. More than 20 percent of Americans over age 60 have type 2 diabetes,
and half of all new diagnoses occur in this age group. Finally, people
who have high blood pressure or high cholesterol may be at higher risk
for developing type 2 diabetes, particularly if they are overweight and
sedentary, as these problems occur together in a condition called the
While the symptoms of type 2 diabetes can be similar to those of type
1, they appear far more gradually; on average, people have type 2 diabetes
for seven years before it is recognized. Often they are diagnosed when
they seek evaluation for fatigue, blurry vision, recurrent or hard-to-heal
infections, or tingling and numbness in hands or feet, or when they develop
diabetes-related health conditions such as heart disease.
For reasons that remain unclear, carrying excess body fat causes insulin
resistance. Consequently, the most important components of type 2 diabetes
management are diet and exercise. Dropping weight and gaining muscle help
the body use insulin more efficiently, and some people can manage their
diabetes with these measures alone. If the pancreas still produces a fair
amount of insulin, oral medications can boost the production to overcome
insulin resistance; after many insulin-producing cells have burned out,
oral medications are no longer enough and supplemental insulin must be
given by injection. Many people with diabetes must also take medication
to control their blood pressure and cholesterol and protect their kidneys.
Before people develop type 2 diabetes they almost always have a period
of pre-diabetes, where their blood sugar levels are slightly higher than
normal, particularly after consuming meals. This condition used to be
called latent diabetes or borderline diabetes, and it affects an estimated
40 percent of the adult population over age 40 in the U.S. Fortunately,
studies have shown that people with pre-diabetes who lose weight and increase
their physical activity can prevent or delay progression to type 2 diabetes.
Pregnant women who have never had high blood sugar before but develop
it during pregnancy are said to have gestational diabetes. About four
percent of pregnant women develop the condition, which generally appears
in the later stages of pregnancy. Similar to type 2 diabetes, gestational
diabetes is caused by insulin resistance.
Hormones produced by the placenta to support the baby’s growth also
block the action of insulin in the mother’s body. Consequently,
women’s insulin requirements may increase by threefold during pregnancy.
If the pancreas cannot keep up, blood sugar levels rise for the mother
and the fetus.
All pregnant women are screened for gestational diabetes in the later
stages of pregnancy because untreated diabetes can create problems for
both mother and baby. The high blood sugar level in fetal circulation
triggers the baby’s pancreas to begin producing insulin and the
baby grows too much, storing the extra sugar as fat. These babies can
become so large that they damage their shoulders passing through the birth
canal. As newborns they may experience breathing problems, and their overdeveloped
pancreatic cells continue to produce extra insulin, causing low blood
sugar after birth. They are more likely to be overweight as children and
to develop type 2 diabetes as adults.
Treatment for gestational diabetes includes special meal plans, scheduled
physical activity and daily blood sugar testing. Some pregnant women need
injections of insulin (which is safe to use because it does not cross
the placenta) to keep their blood sugar within the normal range.
Gestational diabetes usually resolves after pregnancy, but a small number
of women remain with type 2 diabetes after the birth, and all women with
gestational diabetes face increased risk for diabetes down the road. Sixty-five
percent develop gestational diabetes again in subsequent pregnancies,
and 30 to 40 percent develop type 2 diabetes within a decade.
Diagnosis of Diabetes
The preferred test for diagnosing diabetes is the fasting plasma glucose
(FPG) test, a blood test done in the morning after an overnight fast.
Normal levels are 99 mg/dL and below. Levels between 100 and 125 indicate
pre-diabetes, and levels above 125—if confirmed with a repeat test
on another day—mean a diagnosis of diabetes.
The oral glucose tolerance test (OGTT) is more sensitive than the FPG
test for picking up pre-diabetes, but it is less convenient to administer.
Blood glucose is measured after an overnight fast, as with the FPG test,
and then the patient is given a glucose mixture to drink. Blood glucose
levels are measured again two hours later; levels of 139 or below are
in the normal range, levels between 139 and 199 show pre-diabetes, and
levels of 200 and above indicate diabetes.
A blood glucose test drawn at random during the day can be used to test
for diabetes, although this method is less reliable. A level of 200 mg/dL
or greater can indicate diabetes if it is accompanied by symptoms such
as excessive urination, persistent thirst or unexplained weight loss.
The result should be confirmed on another day with an FPG test.
All people aged 45 or over should get an FPG test to screen for diabetes,
especially if they are overweight. People under age 45 should consider
getting tested if they are overweight and have one or more factors increasing
their risk for diabetes, such as family history, a high-risk ethnic group,
high blood pressure or high cholesterol, etc. If pre-diabetes develops,
testing should be repeated every one to two years to watch for any progression
to diabetes. If possible symptoms of diabetes develop at any age, testing
should be done as soon as possible.
One of the most important advances in diabetes treatment and control has
been the ability to measure and monitor blood sugar levels at home. People
with all types of diabetes must understand how the disease works and learn
how to test and manage their blood sugar levels.
The three critical elements for controlling diabetes are food, exercise
and insulin. The rule of thumb is that food makes the glucose level rise
and exercise and insulin make the glucose level fall. Diabetes control
is a constant balancing act involving these three factors, especially
for people with type 1 diabetes. Other factors that can affect the balance
include infection, fatigue, excitement, anxiety, hormonal changes and
periods of growth. If the balance is lost, one of two diabetic emergencies
can emerge: hypoglycemia (low blood sugar) or hyperglycemia (high blood
Hypoglycemia, sometimes called insulin shock, can occur if a person using
insulin eats too little food, doesn’t eat soon enough, takes too
much insulin or exercises too much. Common symptoms include sudden hunger,
crankiness, inappropriate responses, confusion, headache, dizziness, inattention,
lack of coordination, drowsiness, perspiration, pale complexion and trembling;
people have their own characteristic combinations of these symptoms, and
it’s important for them to identify their typical responses because
the condition can lead to unconsciousness if not corrected quickly by
eating sugary foods. Some people show no preliminary symptoms and therefore
need to monitor their blood sugar levels more frequently. If someone experiencing
hypoglycemia becomes unconscious, honey or syrup should be rubbed inside
the person’s cheek where it can be absorbed without posing a risk
Hyperglycemia can be equally dangerous if it is severe and untreated.
A condition called diabetic ketoacidosis (DKA) can develop, usually seen
in people with type 1 diabetes. Since the body can’t use any glucose
to supply its energy needs, it instead burns fats, forming by-product
acids called ketones that poison the system. Symptoms develop over hours
to days and include extreme thirst; dry, hot skin; loss of appetite; drowsiness
and lethargy; heavy or labored breathing; and a sweet, fruity or wine-like
odor on the breath. Ketones and glucose can be detected in the urine as
well as the blood. Eventually the condition progresses to stupor and coma,
presenting a life-threatening emergency that requires hospitalization.
Diet and Exercise
Eating well-balanced meals in the correct amounts helps keep blood glucose
level as close to normal as possible. Consultation from a dietician is
helpful for developing a personal meal plan outlining the types and quantities
of food that can be chosen for meals and snacks. The plan should aim for
a fixed number of calories each day and should be low in fat. Concentrated
sugars should be avoided because the body cannot mobilize insulin fast
enough to counter their rapid effect on blood sugar levels. Many systems
are available to help people follow their diabetes meal plans: the Food
Guide Pyramid, Rate Your Plate, the Diabetic Exchange Lists, and carbohydrate
Exercise is also important, particularly for people with type 2 diabetes,
because it helps control weight and reduces demand on the pancreas to
produce insulin. It is important to maintain a regular pattern of eating,
exercising, and resting. Changes of schedule require adapting the diet
or insulin dosages appropriately. For instance, if dinner will be very
late, a light snack will be needed at the normal dinner hour; similarly,
a snack may be necessary before or after strenuous activities.
Looking into the future, there is increasing hope that diabetes and its
related problems may someday be cured. Researchers are beginning to understand
the autoimmune process that destroys insulin-producing cells, identifying
many of the genes that place people at risk for diabetes, and refining
new treatments such as pancreas transplants. Gene therapy has been used
successfully to cure diabetes in mice by converting some liver cells into
insulin-producing pancreatic cells, and stem cell research may present
similar opportunities, changing the face of diabetes treatment.
by Gillian Friedman, MD
Juvenile Diabetes Research Foundation
American Diabetes Association
National Diabetes Education Program
Other articles in the John
Ratzenberger issue include Letter
from the Editor — Breast Cancer;
Screening; Letter from Congressman Ramstad
— Telehealth Technology; Headlines
— AFB, IBM and Technology Innovators; Humor
— Everybody is Somebody; Etiquette of Grief
— Helpful Tips on How to Respond; Mary Jo
— New Jersey First Lady Speaks Out on
Postpartum Depression; Paralympic Military Program
— California Clinic; Braille Institute
— Seeing Life Through the Camera; Recipes
— Desserts to Feel Good About; Univ. Design/Visitability
— Building Neighborhoods; Employment
— No Hands? No Problem; Events and Conferences...