Complications of Diabetes Mellitus
(See also Diabetes Mellitus.)
People with diabetes mellitus have many serious long-term complications that affect many areas of the body.
There are two types of diabetes mellitus
In both types, the amount of sugar (glucose) in the blood is elevated.
People with either type 1 or type 2 diabetes are likely to have complications as a result of the elevated glucose level. However, because type 2 diabetes may be present for some time before it is diagnosed, complications in type 2 diabetes may be more serious or more advanced when they are discovered.
People with diabetes mellitus may experience many serious, long-term complications. Some of these complications begin within months of the onset of diabetes, although most tend to develop after a few years. Most of the complications gradually worsen. In people with diabetes, strictly controlling the level of glucose in the blood makes these complications less likely to develop or worsen.
Most complications of diabetes are the result of problems with blood vessels. Glucose levels that remain high over a long time cause both the small and large blood vessels to narrow. The narrowing reduces blood flow to many parts of the body, leading to problems. There are several causes of blood vessel narrowing. Complex sugar-based substances build up in the walls of small blood vessels, causing them to thicken and leak. Poor control of blood glucose levels also tends to cause the levels of fatty substances in the blood to rise, resulting in atherosclerosis and decreased blood flow in the larger blood vessels.
Atherosclerosis leads to heart attacks and strokes. Atherosclerosis is between 2 and 4 times more common and tends to occur at a younger age in people with diabetes than in people who do not have diabetes.
Poor circulation to the skin can lead to ulcers and infections and causes wounds to heal slowly. People with diabetes are particularly likely to have ulcers and infections of the feet and legs. Too often, these wounds heal slowly or not at all. When wounds do not heal, this can result in gangrene (tissue death) and amputation of the foot or part of the leg may be needed.
People with diabetes often develop bacterial and fungal infections, typically of the skin. When the levels of glucose in the blood are high, white blood cells cannot effectively fight infections. Any infection that develops tends to be more severe and takes longer to resolve.
Damage to the blood vessels of the eye can cause loss of vision (diabetic retinopathy). Laser surgery can seal the leaking blood vessels of the eye and prevent permanent damage to the retina. Sometimes, other forms of surgery or injectable drugs may be used. Therefore, people with diabetes should have yearly eye examinations to check for early signs of damage.
The kidneys can malfunction, resulting in chronic kidney disease that may require dialysis or kidney transplantation. Doctors usually check the urine of people with diabetes for abnormally high levels of protein (albumin), which is an early sign of kidney damage. At the earliest sign of kidney complications, people are often given angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), drugs that slow the progression of kidney damage.
Damage to nerves can manifest in several ways. If a single nerve malfunctions, an arm or leg may suddenly become weak. If the nerves to the hands, legs, and feet become damaged (diabetic polyneuropathy), sensation may become abnormal, and tingling or burning pain and weakness in the arms and legs may develop. Damage to the nerves of the skin makes repeated injuries more likely because people cannot sense changes in pressure or temperature.
Complications of Diabetes
At the time of diagnosis and then at least yearly, people with type 2 diabetes are monitored for the presence of diabetes complications, such as kidney, eye, and nerve damage. Doctors begin screening tests in people with type 1 diabetes 5 years after diagnosis. Typical screening tests include the following:
Worsening of complications can be prevented or delayed by strict blood glucose control or by early drug treatment. Risk factors for heart problems, such as increased blood pressure and high cholesterol levels, are evaluated at each doctor visit and are treated with drugs if necessary. Another common problem in people with diabetes is gum disease (gingivitis), and regular visits to the dentist for cleaning and preventive care are important.
One of the challenges of trying to strictly control the levels of glucose in the blood is that low blood glucose levels (hypoglycemia) may occur with some commonly used antihyperglycemic drugs (such as insulin or sulfonylureas). Recognizing the presence of low blood glucose is important because treatment of hypoglycemia is an emergency. Symptoms may include hunger pangs, racing heart beat, shakiness, sweating, and inability to think clearly.
If hypoglycemia is very severe, sugar must get into the body quickly to prevent permanent harm and relieve symptoms. Most of the time, people can eat sugar. Almost any form of sugar will do, although glucose works more quickly than table sugar (typical table sugar is sucrose). Many people with diabetes carry glucose tablets or glucose gel packs. Other options are to drink a glass of milk (which contains lactose, a type of sugar), sugar water, or fruit juice or to eat a piece of cake, some fruit, or another sweet food. In more serious situations, it may be necessary for emergency medical practitioners to inject glucose into a vein.
Another treatment for hypoglycemia involves the use of glucagon. Glucagon can be injected into the muscle and causes the liver to release large amounts of glucose within minutes. Small transportable kits containing a syringe filled with glucagon are available for people who frequently have episodes of low blood glucose to use in emergency situations when sugar cannot be ingested by mouth.