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.
Also see: Diabetes Overview | Symptoms & Complications | Diabetes Treatment | Risk Factors & Prevention
Causes of Diabetes
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 18 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.
Symptoms of Diabetes
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
Exams 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.
Diabetes 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 1 diabetes,
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.
Support Groups
For additional information, see
diabetes resources.
Outlook (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.
Possible 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
When to Contact a Medical Professional
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
Prevention of 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.
Also see: Diabetes Overview | Symptoms & Complications | Diabetes Treatment | Risk Factors & Prevention
