DIABETES MELLITUS  
  INTRODUCTION  
 

Diabetes mellitus is a chronic disease that has no cure. It isa serious, lifelong condition afflicting over 2 million people in Canada, and about half of these people do not know they have diabetes and are not under care for the disorder. Diabetes affects people of all ages, but it occurs most often in older adults. It is a leading cause of premature death, blindness, kidney disease, heart disease, stroke, limb amputation and other significant health problems.

 
  WHAT IS DIABETES?  
 

Diabetes is a disorder of metabolism - the way our bodies use digested food for energy and growth. Most of the food we eat is broken down by digestion into a simple sugar called glucose, which is the main source of fuel for the body.

 
 

After digestion, the glucose passes into the bloodstream where it is available to be taken up by body cells to use for energy and growth. For the glucose to get into the cells, insulin must be present. Insulin is a hormone produced by the pancreas, a large gland behind the stomach.

 
 

Normally when we eat, the pancreas automatically produces the right amount of insulin to move the glucose from our blood into our cells. Diabetes mellitus is a condition resulting from an inability of the body to sufficiently produce and/or properly use insulin. In people with diabetes, the pancreas either produces little or no insulin, or the body cells do not respond to the insulin that is produced. As a result, glucose builds up in the blood, overflows into the urine, and passes out of the body. Thus, the body loses its main source of fuel even though the blood contains large amounts of glucose. Chronic high levels of blood glucose due to diabetes are associated with long-term damage, dysfunction and failure of various organs, especially the kidneys, eyes, nerves, heart, and blood vessels.

 
  There are three main types of diabetes:  
 
Type 1 occurs when the pancreas produces little or no insulin.  
  Approximately 10 percent of people with diabetes have Type 1 diabetes.  
Type 2

occurs when the pancreas does not produce enough insulin or when the body does not use the insulin that is produced effectively.

 
  Approximately 90 percent of people with diabetes have Type 2.  
Gestational

is a temporary condition that occurs during pregnancy. It affects two to four percent of all pregnancies with an increased risk of developing diabetes for both mother and child.

 
 
  Type 1 Diabetes  
 

Previously known as insulin-dependent diabetes mellitus (IDDM) or juvenile diabetes, Type 1 typically develops in childhood or adolescence, but it can appear at any age. The most common form of Type 1 diabetes is caused by autoimmune destruction of pancreatic beta-cells, resulting in an inability of the pancreas to produce insulin, therefore requiring daily injections of insulin for survival. An autoimmune disease results when the body's system for fighting infection (the immune system) turns against a part of the body. At present it is not known exactly what causes the body's immune system to attack the beta cells, but it is believed that both genetic factors and viruses are involved.

 
  Symptoms of type 1 diabetes usually develop over a short period although beta cell destruction can begin years earlier.  
  Type 2 Diabetes  
 

Type 2 diabetes (once known as noninsulin-dependent diabetes mellitus or NIDDM) is the most common form of diabetes. This form of diabetes usually develops in adults over the age of 40 and is most common among adults over age 55. About 80 percent of people with type 2 diabetes are overweight.

 
 

In Type 2 diabetes, the pancreas usually produces insulin, but for some reason, the body cannot use the insulin effectively.

 
 

The end result is the same as for type 1 diabetes - an unhealthy build-up of glucose in the blood and an inability of the body to make efficient use of its main source of fuel.

 
 

The symptoms of Type 2 diabetes develop gradually and are not as noticeable as in Type 1 diabetes. Life expectancy is reduced by 5 to 10 years in middle-aged people with Type 2 diabetes. Life expectancy varies with age of onset, the reduction being greater the younger the age at diagnosis.