Diabetes mellitus, often called diabetes, is a condition that makes it hard for the body to control the level of glucose in the blood. This means it is hard for the body to convert food into the energy that the body needs to work. Glucose is the main form of sugar in the body.
What is going on in the body?
Insulin is the hormone responsible for helping glucose (sugar) move into the cells so that the body can use it for fuel. Thus, insulin helps control the level of glucose in the blood.
The pancreas, a long, thin organ located behind the stomach, makes insulin. In healthy people, the pancreas makes extra insulin when a person eats. Insulin moves glucose from the bloodstream into the body cells. The cells use glucose as their main energy source.
In a person with diabetes, the pancreas cannot make enough insulin to keep up with the body's demand. So glucose cannot be moved into the cells and used. In some types of diabetes, the body cells resist the insulin. As a result, glucose builds up in the blood to a high level, a condition known as hyperglycemia.
According to the American Diabetic Association (ADA) about 17 million Americans have diabetes. There are three main types of diabetes.
Type 1 diabetes. This type was formerly known as insulin-dependent diabetes mellitus (IDDM), or juvenile-onset diabetes. A person with this type makes little or no insulin. So he or she needs to take insulin shots each day.
Type 2 diabetes. This type was known as noninsulin-dependent diabetes mellitus (NIDDM), or adult-onset diabetes. In this, by far the most common type, a person might make healthy or even high levels of insulin, but obesity makes his or her body resistant to its effect. Type 2 diabetes was once rare in children. However, with the increase in obesity in children, doctors are now finding that as many as 1 out of each 20 children with diabetes has type 2. Of these children, 85% are obese.
Gestational diabetes or pregnancy-induced diabetes. This type of diabetes develops in a pregnant woman. The mechanism is similar to type 2 except that the insulin resistance is believed to be fueled by the hormones of pregnancy. In most cases, this type of diabetes goes away after the woman's child is born.
There are other, much less common, types of diabetes. These include diabetes caused by:
a genetic defect, diseases where the pancreas is infected, inflamed, or otherwise damaged,
hormonal imbalances (e.g. Cushing syndrome), or
from being exposed to certain chemicals or medications, such as prednisone, oral contraceptives, or thiazide diuretics.
What are the causes and risks of the disease?
Genetics may play a part in all types of diabetes mellitus. Other causes and risks vary. They depend on the type of diabetes involved. Type 1 diabetes is believed to be an autoimmune disorder, in which the body makes antibodies that destroy pancreatic cells. It is more common in whites than in other racial groups.
Type 2 diabetes occurs when the cells in the body are resistant to insulin. As a result, the body cannot use blood glucose as well as it should. Risk factors for type 2 diabetes include:
- Obesity. This is the main cause of type 2 diabetes in both adults and children. A recent study showed a 33% increase in the number of Americans with type 2 diabetes over the past 8 years. The increase was 70% in people ages 30 to 39 years old and was linked to a sharp rise in obesity in this group.
- Race. This type of diabetes is more common in African Americans, Hispanic Americans, Asian Americans, Native Americans, and Pacific Islanders.
- Lack of physical exercise. A recent study showed that walking briskly for 30 minutes a day at least 5 days a week reduces a woman's risk of type 2 diabetes.
- High blood pressure. Experts define this as a blood pressure equal to or greater than 140/90.
- Low HDL level, known as "good" or "healthy" cholesterol, and high triglyceride level. HDL levels equal to or less than 40 mg/dL and/or a triglyceride level greater than or equal to 250 mg/dL are considered unhealthy.
- Age of 45 or older.
- History of gestational diabetes, or having babies that weighed more than 9 pounds at birth.
- Hormonal changes linked to menopause. A recent study of 16,000 American women between the ages of 40 and 65 showed that diabetes was one of the top six diseases diagnosed. A long-term study is under way to see if menopause and changes in hormone level are factors in the development of type 2 diabetes.
Gestational diabetes is considered when a woman has any abnormal glucose test result during pregnancy. It is believed to be the result of increased hormone levels during pregnancy, which work against insulin. Weight gain during pregnancy might also be a factor in causing gestational diabetes.
Almost all people who develop type 2 diabetes have a condition called pre-diabetes first. This condition was formerly known as impaired glucose tolerance or impaired fasting glucose, and the ADA estimates that almost 16 million people over the age of 40 have it. This condition occurs when blood sugar levels are higher than healthy levels but too low to be diagnosed as diabetes. Without lifestyle changes, most people who have pre-diabetes will progress to type 2 diabetes within 10 years.
What can be done to prevent the disease?
At present, there is no way to prevent type 1 diabetes. However, in many cases, it may be possible to prevent pre-diabetes from progressing to type 2 diabetes. Even modest lifestyle changes can help. This is why it is very important to recognize pre-diabetes.
The keys are to:
- eat a healthy diet
- exercise 30 minutes a day at least 5 days a week
- maintain a healthy body weight
How is the disease diagnosed?
A doctor may suspect diabetes after taking a person's health history and doing a physical exam. Based on those results, the doctor may want to check for a high glucose level in the blood. There are several types of blood tests doctors can use to diagnose diabetes, including:
- fasting blood sugar (FBS) test, the method used to diagnose most cases of diabetes. In this test, a person is asked to fast overnight for at least 8 hours. In the morning, the level of glucose in the blood is then checked. Healthy FBS levels are less than 100 milligrams per deciliter or mg/dL. An FBS level of more than 126 mg/dL usually suggests diabetes. Levels between 100 and 126 mg/dL are seen in pre-diabetes.
- oral glucose tolerance test, the preferred way to diagnose gestational diabetes. It can also be used to diagnose type 2 diabetes or pre-diabetes. In this test, a person is asked to drink a sweet liquid. Blood samples are then drawn at timed intervals. If a person does not have diabetes, the glucose levels will rise and then fall quickly after drinking the sweet liquid. When a person has diabetes, glucose levels will rise higher and fail to come down as fast as those in a person without diabetes. If the blood sugar level is 140 to 199 mg/dL 2 hours after drinking the liquid, a diagnosis of pre-diabetes can be made.
- non-fasting blood sugar test, which is used as a screening tool. A level of 200 mg/dL or higher suggests diabetes. If the level is above 200 mg/dL, an FBS test or oral glucose tolerance test can be done to confirm the diagnosis of diabetes.
Long Term Effects
What are the long-term effects of the disease?
Over time, high blood sugar levels damage blood vessels, nerves, and other internal structures. Long-term effects of diabetes may include:
Some of these long-term effects may begin even at the moderate-high levels of blood glucose seen in pre-diabetes. This is why it is important to eat a healthy diet, exercise 30 minutes a day, and keep body weight within a healthy range. All of these actions can keep blood sugar within healthy levels. People with diabetes risk factors should also be screened for pre-diabetes on a regular basis.
What are the risks to others?
Diabetes is not contagious and poses no risk to others. It is more common if other family members also have diabetes.
What are the treatments for the disease?
Treatment depends on the type of diabetes that is present. A person with type 1 diabetes will most likely need insulin shots each day. These shots replace the insulin that the pancreas cannot make on its own. A proper diet is also a key to staying healthy.
Gestational diabetes is also usually treated with diet and insulin shots as needed.
The most effective treatment available for type 2 diabetes is a change in lifestyle, including the following:
A person with type 2 diabetes may also be treated with oral medicines and/or insulin shots. Diabetes pills can work in four ways.
Treating the underlying condition or stopping a certain medicine may correct diabetes that is caused by medicine or an illness. If this is not possible, diet, exercise, and pills or shots are used to control the blood sugar.
Careful monitoring and management help keep diabetes under control and reduce the risk of long-term effects. A person with diabetes should:
- monitor his or her blood sugar levels at home
- take mediciens as prescribed by the doctor
- know how to recognize and treat hypoglycemia, which is low blood sugar
- get regular eye checkups that include an examination of the retina after the pupil of the eye has been dilated with eye drops
- do thorough foot care on a daily basis
- follow a plan to monitor and treat changing blood glucose levels when sick or under stress
- follow a healthy diet
- have regular checkups with the healthcare provider
- get a pneumonia shot
- get a flu shot each fall
Treating the complications of diabetes may involve many different specialists. For example, a person with diabetes may need to see eye, heart, foot, hormone, and circulation specialists. Dieticians also help people with diabetes by designing a healthy eating plan. Dieticians can also suggest healthy calorie intake levels and types of foods to eat.
What are the side effects of the treatments?
Side effects depend on the treatments used. If a person has too much insulin in his or her body, the blood glucose levels can drop too low. This condition, called hypoglycemia, can cause the following symptoms:
The usual treatment for low blood glucose is to drink a sweet beverage or eat a sweet food. If low blood sugar goes untreated, a person may pass out or have seizures. Emergency medical care is crucial in this situation.
Some of the oral medicines used for type 2 diabetes may cause weight loss or gain, allergic reactions, or liver damage. Some may also cause low blood glucose levels.
What happens after treatment for the disease?
Diabetes generally cannot be cured, but it can be controlled with careful management and treatment. A person with diabetes will need to have close medical follow-up throughout his or her life to control blood sugar levels and prevent serious complications.
How is the disease monitored?
A person with diabetes should keep all of his or her appointments with his or her primary healthcare provider, as well as other scheduled specialists. Physical exams, blood tests, urine tests, foot and skin care, routine eye exams, and routine dental care are all part of basic care for a person with diabetes.
The main goal of treatment is to keep blood sugar levels as close to a healthy range as is safely possible. In general, ideal ranges of blood sugar levels are 80 to 120 milligrams per deciliter (mg/dL) before meals and 100 to 140 mg/dL at bedtime. Any new or worsening symptoms should be reported to the doctor.
There are also home monitors that measure fructosamine, which is the glycosylation of different blood proteins. Sometimes called the glycoprotein test, this measures control of diabetes over about a 2-week period of time.
A test called the glycosylated hemoglobin or hemoglobin A1C (HbA1C ) measures the average blood sugar levels for the previous three months and can be done in diabetics every three to six month.
The normal range for HbA1C is usually about 4% to 6% in people without diabetes. The goal for people with diabetes is a level of 7% or less. If HbA1C is higher than that, the healthcare provider will often make adjustments in the person's diabetes treatment plan.
HbA1C home test kits that can be done with a fingerstick and test strips that are sent to a lab will be available soon.