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Diabetes mellitus is a chronic disease which
causes serious health complications including renal (kidney) failure,
heart disease, stroke, and blindness. Approximately 14 million
Americans (about 5% of the population) have diabetes. Unfortunately,
as many as one-half of them are unaware that they have it.
Background
Every cell in the human body needs energy in order to function. The
body's primary energy source is glucose, a simple sugar resulting
from the digestion of foods containing carbohydrates (sugars and
starches). Glucose from the digested food circulates in the blood as
a ready energy source for any cells that need it. Insulin is a
hormone or chemical produced by cells in the pancreas, an organ
located behind the stomach. Insulin bonds to a receptor site on the
outside of cell and acts like a key to open a doorway into the cell
through which glucose can enter. Some of the glucose can be
converted to concentrated energy sources like glycogen or fatty
acids and saved for later use. When there is not enough insulin
produced or when the doorway no longer recognizes the insulin key,
glucose stays in the blood rather entering the cells.
The body will attempt to dilute the high level of glucose in the
blood, a condition called hyperglycemia, by drawing water out of the
cells and into the bloodstream in an effort to dilute the sugar and
excrete it in the urine. It is not unusual for people with
undiagnosed diabetes to be constantly thirsty, to drink large
quantities of water, and to urinate frequently as their bodies try
to get rid of the extra glucose. This creates high levels of glucose
in the urine.
At the same time that the body is trying to get rid of glucose from
the blood, the cells are starving for glucose and sending signals to
the body to eat more food, thus making patients extremely hungry. To
provide energy for the starving cells, the body also tries to
convert fats and proteins to glucose. The breakdown of fats and
proteins for energy causes acid compounds called ketones to form in
the blood. Ketones will also be excreted in the urine. As ketones
build up in the blood, a condition called ketoacidosis can occur.
This condition can be life threatening if left untreated, leading to
coma and death.
Types of diabetes mellitus
Type I diabetes, sometimes called juvenile diabetes, begins most
commonly in childhood or adolescence. In this form of diabetes, the
body produces little or no insulin. It is characterized by a sudden
onset and occurs more frequently in populations descended from
Northern European countries (Finland, Scotland, Scandinavia) than in
those from Southern European countries, the Middle East, or Asia. In
the United States, approximately 3 people in 1000 develop Type I
diabetes. This form is also called insulin-dependent diabetes
because people who develop this type need to have daily injections
of insulin.
Brittle diabetics are a subgroup of Type I where patients have
frequent and rapid swings of blood sugar levels between
hyperglycemia (a condition where there is too much glucose or sugar
in the blood) and hypoglycemia (a condition where there is
abnormally low levels of glucose or sugar in the blood). These
patients may require several injections of different types of
insulin during the day to keep the blood sugar level within a fairly
normal range.
The more common form of diabetes, Type II, occurs in approximately
3–5% of Americans under 50 years of age, and increases to 10–15% in
those over 50. More than 90% of the diabetics in the United States
are Type II diabetics. Sometimes called age-onset or adult-onset
diabetes, this form of diabetes occurs most often in people who are
overweight and who do not exercise. It is also more common in people
of Native American, Hispanic, and African-American descent. People
who have migrated to Western cultures from East India, Japan, and
Australian Aboriginal cultures are also more likely to develop Type
II diabetes than those who remain in their original countries.
Type II is considered a milder form of diabetes because of its slow
onset (sometimes developing over the course of several years) and
because it can usually be controlled with diet and oral medication.
The consequences of uncontrolled and untreated Type II diabetes,
however, are the just as serious as those for Type I. This form is
also called noninsulin-dependent diabetes, a term that is somewhat
misleading. Many people with Type II diabetes can control the
condition with diet and oral medications, however, insulin
injections are sometimes necessary if treatment with diet and oral
medication is not working.
Another form of diabetes called gestational diabetes can develop
during pregnancy and generally resolves after the baby is delivered.
This diabetic condition develops during the second or third
trimester of pregnancy in about 2% of pregnancies. The condition is
usually treated by diet, however, insulin injections may be required.
These women who have diabetes during pregnancy are at higher risk
for developing Type II diabetes within 5–10 years.
Diabetes can also develop as a result of pancreatic disease,
alcoholism, malnutrition, or other severe illnesses that stress the
body. |
