Diabetes
Diabetes is a disorder of the metabolism—the way our bodies use digested
food for growth and energy. Most of the food we eat is broken down into
glucose, the form of sugar in the blood. Glucose is the main source of fuel for
the body.
After digestion, glucose passes into the bloodstream, where it is used by
cells for growth and energy. For glucose to get into cells, insulin must be
present. Insulin is a hormone produced by the pancreas, a large gland behind
the stomach.
When we eat, the pancreas automatically produces the right amount of insulin
to move glucose from blood into our cells. In people with diabetes, however,
the pancreas either produces little or no insulin, or the cells do not respond
appropriately to the insulin that is produced. Glucose builds up in the blood,
overflows into the urine, and passes out of the body in the urine. Thus, the
body loses its main source of fuel even though the blood contains large amounts
of glucose.
Types of Diabetes
The three main types of diabetes are :
Type 1 Diabetes
Type 2 Diabetes
Gestational Diabetes
Type 1 Diabetes
Type 1 diabetes is 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 and destroys the
insulin-producing beta cells in the pancreas. The pancreas then produces little
or no insulin. A person who has type 1 diabetes must take insulin daily 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 autoimmune, genetic, and
environmental factors, possibly viruses, are involved. Type 1 diabetes accounts
for about 10 percent of diagnosed diabetes in Canada. It develops most often in
children and young adults but 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 may include increased
thirst and urination, constant hunger, weight loss, blurred vision, and extreme
fatigue. If not diagnosed and treated with insulin, a person with type 1
diabetes can lapse into a life-threatening diabetic coma, also known as
diabetic ketoacidosis.
Type 2 Diabetes
The most common form of diabetes is type 2 diabetes. About 90 percent of
people with diabetes have type 2. This form of diabetes is most often
associated with older age, obesity, family history of diabetes, previous
history of gestational diabetes, physical inactivity, and certain ethnicities.
Type 2 diabetes is increasingly being diagnosed in children and adolescents.
However, nationally representative data on prevalence of type 2 diabetes in
youth are not available.
When type 2 diabetes is diagnosed, the pancreas is usually producing enough
insulin, but for unknown reasons the body cannot use the insulin effectively, a
condition called insulin resistance. After several years, insulin production
decreases. The result is the same as for type 1 diabetes—glucose builds up in
the blood and the body cannot make efficient use of its main source of
fuel.
The symptoms of type 2 diabetes develop gradually. Their onset is not as
sudden as in type 1 diabetes. Symptoms may include fatigue, frequent urination,
increased thirst and hunger, weight loss, blurred vision, and slow healing of
wounds or sores. Some people have no symptoms.
Gestational Diabetes
Some women develop gestational diabetes late in pregnancy. Although this
form of diabetes usually disappears after the birth of the baby, women who have
had gestational diabetes have a 20 to 50 percent chance of developing type 2
diabetes within 5 to 10 years. Maintaining a reasonable body weight and being
physically active may help prevent development of type 2 diabetes.
About 2 to 4 percent of pregnant women in Canada develop gestational
diabetes. As with type 2 diabetes, gestational diabetes occurs more often in
some ethnic groups and among women with a family history of diabetes.
Gestational diabetes is caused by the hormones of pregnancy or a shortage of
insulin. Women with gestational diabetes may not experience any symptoms.
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The Canadian Diabetes Association's “2003 clinical practice guidelines for
the management of diabetes in Canada” provides definite goals for levels of
glucose control for people with diabetes.
Visit the Canadian Diabetes Association Web site and consult your doctor for
more information.
