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Type 2 diabetes mellitus, more often known as type 2 diabetes, is a disease in which the cells of the body do not use insulin effectively. Insulin, a hormone produced by an organ called the pancreas, helps regulate the level of glucose in the blood. Glucose is the main form of sugar in the body. There are other forms of diabetes as well.
What is going on in the body?
The pancreas, a long, thin organ located behind the stomach, makes insulin. Normally, the pancreas makes extra insulin when a person eats. Insulin moves glucose from the bloodstream to the inside of body cells. This glucose, or sugar, is an important source of energy for the cells of the body.
The pancreas produces insulin. In a person with type 2 diabetes, however, the quantity may not be sufficient. Also, the body cells of a person with type 2 diabetes are resistant to the insulin. As a result, glucose is not picked up by the cells. The amount of glucose in the blood becomes abnormally high, causing a condition called hyperglycaemia.
Type 2 diabetes is the most common form of diabetes in Australia. It accounts for about 85% to 90% of the cases of diabetes. Type 2 diabetes used to be rare in children, but is now diagnosed a lot more frequently in children. Of the children diagnosed with type 2 diabetes, 85% are obese. While most children diagnosed with type 2 diabetes are 10 years of age or older, researchers are predicting an increase in the diagnosis of type 2 diabetes in younger children who become obese.
What are the signs and symptoms of the disease?
Symptoms of type 2 diabetes usually develop slowly over time, and are not as noticeable as in type 1 diabetes. Symptoms include: What are the causes and risks of the disease?
Obesity is the main cause of type 2 diabetes in both adults and children.
Lack of physical activity contributes significantly to the development of type 2 diabetes. A recent study showed that walking briskly for 3 hours a week, or exercising vigorously for an hour and a half each week, reduced a woman's risk of type 2 diabetes by 40%.
Type 2 diabetes is more common in people with a family history of the disease. It's also more common among Indigenous Australians and Asians.
Other risk factors for the development of type 2 diabetes include:
What can be done to prevent the disease?
The best way to prevent type 2 diabetes is to maintain a healthy body weight, eat an appropriate diet for diabetes, and exercise regularly. If these methods are not entirely successful, oral medications or injections may added to the treatment plan.
How is the disease diagnosed?
A doctor may suspect diabetes after completing a medical history and performing a physical examination. Diagnosis of diabetes is based on a high glucose level in the blood.
A blood test known as the fasting plasma glucose test may be ordered. In this test, the level of glucose in the blood is checked after a person has not had anything to eat or drink for 8 hours. Normal fasting plasma glucose levels are less than 6 mmol/L (millimoles per litre). A fasting plasma glucose level of more than 8 mmol/L usually indicates diabetes mellitus. A blood glucose level of 11 mmol/L or higher, when done randomly or without fasting first, also usually indicates diabetes.
Further blood sugar tests, such as a random blood sugar test or the oral glucose tolerance test can help determine the specific type of diabetes.
What are the long-term effects of the disease?
High blood sugar levels, if left untreated, damage blood vessels, nerves, and other internal structures. Long-term effects of type 2 diabetes may include:
What are the risks to others?
- retinopathy, a disease of the retina of the eye that can cause blindness. Diabetes is the leading cause of blindness in adults under 40 years of age.
- diabetic nephropathy, a disease of the kidneys that can lead to a form of kidney failure known as chronic renal failure. Diabetes is the number one cause of chronic renal failure.
- arteriosclerosis, or hardening of the arteries, which can lead to heart attacks and strokes. It can also cause poor circulation in the legs and feet.
- diabetic neuropathy, or damage to nerves in the limbs, which can cause numbness and pain in the hands and feet. This, combined with poor circulation, can result in serious diabetic foot ulcers and leg infections that may require amputation.
- autonomic neuropathy, which may cause problems with digestion, diarrhoea, erectile dysfunction, a rapid heartbeat, and low blood pressure
- skin infections, especially fungal infections such as ringworm, jock itch, and athlete's foot. Bacterial infections of the feet are also common and can be life threatening.
- vaginal yeast infections, because high levels of sugar encourage the growth of yeast
- urinary tract infections
- coma or death, which may occur if diabetes gets seriously out of control
Type 2 diabetes is not contagious and poses no risk to others, but it does tend to run in families.
What are the treatments for the disease?
The most effective treatment available for type 2 diabetes is weight loss. A proper diet for diabetes and regular exercise designed for people who have diabetes are very important.
Careful monitoring and management help keep diabetes under control and reduce the risk of long-term effects. A person with type 2 diabetes is advised to: A person with type 2 diabetes may also be treated with oral medications or insulin injections, or both. The oral medications stimulate the pancreas to make more insulin or help the cells in the body use insulin and glucose more effectively. If medication is needed, doses must be balanced with meals, daily activities, stress, and illness, all of which may affect the glucose level in the blood. Careful monitoring and management helps keep diabetes under control and reduce long-term effects.
There are a number of medications that may be used to treat type 2 diabetes. Sometimes a single medication will be used, and sometimes a combination of medications will be recommended. These medications fall into the following categories:
Treating the complications of diabetes may involve many different specialists. Examples include eye, heart, foot, hormone, and circulation specialists. Dieticians also help people with diabetes by designing an eating plan with suggestions for appropriate kilojoule intake and best types of foods to eat.
- sulphonylurea medications, such as daonil, medidiab and amaryl. These medications stimulate the beta cells in the pancreas to release more insulin.
- metformin, which helps insulin work better, mostly in the liver
- thiazolidinediones, which help insulin work better in the muscle and fat
- alpha-glucosidase inhibitors, such as acarbose, which lower blood sugar by blocking the breakdown of starches and some sugars
- insulin, which may be needed from the onset of type 2 diabetes or later in life
What are the side effects of the treatments?
The oral medications used for type 2 diabetes mellitus may cause weight gain, diarrhoea, flatulence, allergic reactions, or liver damage. Some may also cause low blood sugar. If a person has too much insulin in his or her body, the blood glucose levels can drop too low. This condition is known as hypoglycaemia, which can cause nervousness, shakiness, and confusion. If this condition goes untreated, a person can pass out. The usual treatment for low blood sugar is to eat or drink a sweet beverage or food. If symptoms progress to passing out or the body having spasm or seizures, Medical attention is needed immediately if the person passes out or has spasm or seizures.
What happens after treatment for the disease?
Although type 2 diabetes cannot be cured, it can be controlled with careful management and treatment. Type 2 diabetes requires lifelong monitoring and treatment. Some people with type 2 diabetes might mistakenly think that their condition is borderline, or not as serious as type 1 diabetes. However, blood sugar levels in type 2 diabetes must be cautiously controlled over a lifetime to help prevent serious complications.
How is the disease monitored?
A person with type 2 diabetes should keep all of his or her appointments with the main doctor and other specialists. Physical examinations, blood tests, urine tests, foot and skin care, regular eye examinations, and regular dental checkups are an important part of basic care for a person with diabetes.
The main goal of treatment is to keep blood sugar levels as close to normal as is safely possible. In general, ideal ranges of blood sugar levels are 4 - 6 mmol/L (millimoles per litre) before meals and 6 - 8 mmol/L at bedtime.
Author: Eileen McLaughlin, RN, BSN
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request