Diabetes
Diabetes is a life-long disease marked by high levels
of sugar in the blood. It can be caused by too little
insulin (a hormone produced by the pancreas to regulate
blood sugar), resistance to insulin, or both.
Causes, incidence, and risk factors
To understand diabetes, it is important to first understand
the normal process of food metabolism. Several things
happen when food is digested:
- A sugar called glucose enters the bloodstream. Glucose
is a source of fuel for the body.
- An organ called the pancreas makes insulin. The
role of insulin is to move glucose from the bloodstream
into muscle, fat, and liver cells, where it can be
used as fuel.
People with diabetes have high blood glucose. This
is because their pancreas does not make enough insulin
or their muscle, fat, and liver cells do not respond
to insulin normally, or both.
There are three major
types of diabetes:
Type 1 diabetes is usually diagnosed
in childhood. The body makes little or no insulin, and
daily injections of insulin are required to sustain
life. Without proper daily management, medical emergencies
can arise.
Type 2 diabetes is far more common
than type 1 and makes up 90% or more of all cases of
diabetes. It usually occurs in adulthood. Here, the
pancreas does not make enough insulin to keep blood
glucose levels normal, often because the body does not
respond well to the insulin. Many people with type 2
diabetes do not know they have it, although it is a
serious condition. Type 2 diabetes is becoming more
common due to the growing number of older Americans,
increasing obesity, and failure to exercise.
Gestational diabetes is high blood
glucose that develops at any time during pregnancy in
a person who does not have diabetes.
Diabetes affects about 17 million Americans. There
are many risk factors for diabetes, including:
- A parent, brother, or sister with diabetes
- Obesity
- Age greater than 45 years
- Some ethnic groups (particularly African-Americans
and Hispanic Americans)
- Gestational diabetes or delivering a baby weighing
more than 9 pounds
- High blood pressure
- High blood levels of triglycerides (a type of fat
molecule)
- High blood cholesterol level
The American Diabetes Association recommends that
all adults be screened for diabetes at least every three
years. A person at high risk should be screened more
often.
High blood levels of glucose can cause several problems,
including frequent urination, excessive thirst, hunger,
fatigue, weight loss, and blurry vision. However, because
type 2 diabetes develops slowly, some people with high
blood sugar experience no symptoms at all.
Symptoms of type 1 diabetes:
- Increased thirst
- Increased urination
- Weight loss in spite of increased appetite
- Fatigue
- Nausea
- Vomiting
Symptoms of type 2 diabetes:
- Increased thirst
- Increased urination
- Increased appetite
- Fatigue
- Blurred vision
- Slow-healing infections
- Impotence in men
Signs and tests
A urine analysis may be used to look for glucose and
ketones from the breakdown of fat. However, a urine
test alone does not diagnose diabetes. The following
blood glucose tests are used to diagnose diabetes:
- Fasting blood glucose level -- diabetes is diagnosed
if higher than 126 mg/dL on two occasions. Levels
between 100 and 126 mg/dl are referred to as impaired
fasting glucose or pre-diabetes. These levels are
considered to be risk factors for type 2 diabetes
and its complications.
- Random (non-fasting) blood glucose level -- diabetes
is suspected if higher than 200 mg/dL and accompanied
by the classic symptoms of increased thirst, urination,
and fatigue. (This test must be confirmed with a fasting
blood glucose test.)
- Oral glucose tolerance test -- diabetes is diagnosed
if glucose level is higher than 200 mg/dL after 2
hours (This test is used more for type 2 diabetes.)
Patients with type 1 diabetes usually develop symptoms
over a short period of time, and the condition is
often diagnosed in an emergency setting. In addition
to having high glucose levels, acutely ill type 1
diabetics have high levels of ketones.
Ketones are produced by the breakdown of fat and muscle,
and they are toxic at high levels. Ketones in the blood
cause a condition called "acidosis" (low blood
pH). Urine testing detects both glucose and ketones
in the urine. Blood glucose levels are also high.
Treatment
There is no cure for diabetes. The immediate goals
are to stabilize your blood sugar and eliminate the
symptoms of high blood sugar. The long-term goals of
treatment are to prolong life, relieve symptoms, and
prevent long-term complications such as heart disease
and kidney failure.
LEARN THESE SKILLS
Basic diabetes management skills will help prevent
the need for emergency care. These skills include:
- How to recognize and treat low blood sugar (hypoglycemia)
and high blood sugar (hyperglycemia)
- What to eat and when
- How to take insulin or oral medication
- How to test and record blood glucose
- How to test urine for ketones (type 1 diabetes
only)
- How to adjust insulin and/or food intake when changing
exercise and eating habits
- How to handle sick days
- Where to buy diabetes supplies and how to store
them
After you learn the basics of diabetes care, learn
how the disease can cause long-term health problems
and the best ways to prevent these problems. People
with diabetes need to review and update their knowledge,
because new research and improved ways to treat diabetes
are constantly being developed.
WHAT TO EAT
You should work closely with your health care provider
to learn how much fat, protein, and carbohydrates you
need in your diet. Your specific meal plans need to
be tailored to your food habits and preferences. People
with type 1 diabetes should eat at about the same times
each day and try to be consistent with the types of
food they choose. This helps to prevent blood sugars
from becoming extremely high or low. Type 2 diabetics
should follow a well-balanced and low-fat diet.
A registered dietician can be very helpful in planning
dietary needs.
Weight management is important to achieving control
of diabetes. Some people with type 2 diabetes can stop
medications after losing excess weight, although the
diabetes is still present.
HOW TO TAKE INSULIN OR ORAL MEDICATION
Medications to treat diabetes include insulin and glucose-lowering
pills, called oral hypoglycemic agents. The bodies of
people with type 1 diabetes cannot make their own insulin,
so daily insulin injections are required. The bodies
of people with type 2 diabetes make insulin but cannot
use it effectively.
Insulin is not available in oral form. It is delivered
by injections that are generally required one to four
times per day. Some people use an insulin pump, which
is worn at all times and delivers a steady flow of insulin
throughout the day.
Insulin preparations differ in how quickly they start
to work and how long they remain active. Sometimes different
types of insulin are mixed together in a single injection.
The types of insulin to use, the doses required, and
the number of daily injections are chosen by a health
care professional trained to provide diabetes care.
People who need insulin are taught to give themselves
injections by their health care providers or diabetes
educators.
Unlike type 1 diabetes, type 2 diabetes may respond
to treatment with exercise, diet, and/or oral medications.
There are several oral hypoglycemic agents that lower
blood glucose in type 2 diabetes. They fall into one
of three groups:
- Medications that increase insulin production by
the pancreas. These include Amaryl, Glucotrol, and
Glucotrol XL, Micronase, Diabeta, Glynase, Prandin,
and Starlix.
- Medications that increase sensitivity to insulin.
These include Glucophage, Avandia, and Actos.
- Medications that delay absorption of glucose from
the gut. These include Precose and Glyset.
Most type 2 diabetics will require more than one medication
for good blood sugar control within three years of starting
their first medication. Different groups of oral medications
may be combined, or insulin and oral medications may
be used together.
Some people with type 2 diabetes find they no longer
need medication if they lose weight and increase activity,
because when their ideal weight is reached, their own
insulin and a careful diet can control their blood glucose
levels.
Oral hypoglycemic agents are not known to be safe for
use in pregnancy; women who have type 2 diabetes and
take these medications may be switched to insulin during
pregnancy and while breast-feeding.
Gestational diabetes is treated with diet and insulin.
SELF-TESTING
Self-monitoring of blood glucose is done by checking
the glucose content of a drop of blood. Regular testing
tells you how well diet, medication, and exercise are
working together to control your diabetes.
The results of the test can be used to adjust meals,
activity, or medications to keep blood sugar levels
in an appropriate range. Testing provides valuable information
for the health care provider and identifies high and
low blood sugar levels before serious problems develop.
The American Diabetes Association recommends that premeal
blood sugar levels fall in the range of 80 to 120 mg/dL
and bedtime blood levels fall in the range of 100 to
140 mg/dL. Your doctor may adjust this depending on
your circumstances.
You should also ask your doctor how often to check
your hemoglobin A1c (HbA1c) level. The HbA1c is a measure
of average blood glucose during the previous two to
three months. It is a very helpful way to monitor a
patient's overall response to diabetes treatment over
time. A person without diabetes has an HbA1c around
5%. People with diabetes should try to keep it below
7%.
Ketone testing is another test that is used in type
1 diabetes. Ketones build up in the blood when there
is not enough insulin in people with type 1diabetes,
eventually "spilling over" into the urine.
The ketone test is done on a urine sample. High levels
of blood ketones may result in a serious condition called
ketoacidosis. Ketone testing is usually done at the
following times:
- When the blood sugar is higher than 240 mg/dL
- During acute illness (for example, pneumonia, heart
attack, or stroke)
- When nausea or vomiting occur
- During pregnancy
EXERCISE
Regular exercise is especially important for people
with diabetes. It helps with blood sugar control, weight
loss, and high blood pressure. People with diabetes
who exercise are less likely to experience a heart attack
or stroke than diabetics who do not exercise regularly.
You should be evaluated by your physician before starting
an exercise program.
Here are some exercise considerations:
- Choose an enjoyable physical activity that is appropriate
for your current fitness level.
- Exercise every day, and at the same time of day,
if possible.
- Monitor blood glucose levels before and after exercise.
- Carry food that contains a fast-acting carbohydrate
in case you become hypoglycemic during or after exercise.
- Carry a diabetes identification card and a mobile
phone or change for a payphone in case of emergency.
- Drink extra fluids that do not contain sugar before,
during, and after exercise.
Changes in exercise intensity or duration may require
changes in diet or medication dose to keep blood sugar
levels from going too high or low.
FOOT CARE
People with diabetes are prone to foot problems because
of the likelihood of damage to blood vessels and nerves
and a decreased ability to fight infection. Problems
with blood flow and damage to nerves may cause an injury
to the foot to go unnoticed until infection develops.
Death of skin and other tissue can occur.
If left untreated, the affected foot may need to be
amputated. Diabetes is the most common condition leading
to amputations.
To prevent injury to the feet, people with diabetes
should adopt a daily routine of checking and caring
for the feet as follows:
- Check your feet every day, and report sores or changes
and signs of infection.
- Wash your feet every day with lukewarm water and
mild soap, and dry them thoroughly.
- Soften dry skin with lotion or petroleum jelly.
- Protect feet with comfortable, well-fitting shoes.
- Exercise daily to promote good circulation.
- See a podiatrist for foot problems or to have corns
or calluses removed.
- Remove shoes and socks during a visit to your health
care provider and remind him or her to examine your
feet.
- Stop smoking, which hinders blood flow to the feet.
Expectations / Prognosis
The risks of long-term complications from diabetes
can be reduced.
The Diabetes Control and Complications Trial (DCCT)
studied the effects of tight blood sugar control on
complications in type 1 diabetes. Patients treated for
tight blood glucose control had an average HbA1c of
approximately 7%, while patients treated less aggressively
had an average HbA1c of about 9%. At the end of the
study, the tight blood glucose group had dramatically
fewer cases of kidney disease, eye disease, and nervous
system disease than the less-aggressively treated patients.
In the United Kingdom Prospective Diabetes Study (UKPDS),
researchers followed nearly 4,000 people with type 2
diabetes for 10 years. The study monitored how tight
control of blood glucose (HbA1c of 7% or less) and blood
pressure (less than 144 over less than 82) could protect
a person from the long-term complications of diabetes.
This study found dramatically lower rates of kidney,
eye, and nervous system complications in patients with
tight control of blood glucose. In addition, there was
a significant drop in all diabetes-related deaths, including
lower risks of heart attack and stroke. Tight control
of blood pressure was also found to lower the risks
of heart disease and stroke.
The results of the DCCT and the UKPDS dramatically
demonstrate that good blood glucose and blood pressure
control, many of the complications of diabetes can be
prevented.
Complications
Emergency complications include diabetic hyperglycemic
hyperosmolar coma.
Long-term complications include:
- Diabetic retinopathy
- Diabetic nephropathy
- Diabetic neuropathy
- Peripheral vascular disease
- Hyperlipidemia, hypertension, atherosclerosis,
and coronary artery disease
Calling your health care provider
Go to the emergency room or call the local emergency
number (such as 911) if symptoms of ketoacidosis occur:
- Increased thirst and urination
- Nausea
- Deep and rapid breathing
- Abdominal pain
- Sweet-smelling breath
- Loss of consciousness
Go to the emergency room or call the local emergency
number if symptoms of extremely low blood sugar (hypoglycemic
coma or severe insulin reaction) occur:
- Weakness
- Drowsiness
- Headache
- Confusion
- Dizziness
- Double vision
- Lack of coordination
- Convulsions or unconsciousness
Basic Prevention of Type 2 Diabetes
Maintaining an ideal body weight and an active lifestyle
may prevent the onset of type 2 diabetes. Currently
there is no way to prevent type 1 diabetes.
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