There are three main types of diabetes as follows:
Type 1 diabetes occurs when the beta cells of the pancreas are destroyed by the immune system and no longer produce insulin which the body needs in adequate supply to help it function. There is no known way to prevent type 1 diabetes; it usually develops in childhood or adolescence. According to the Juvenile Diabetes Research Foundation Canada, five to 10% of people with diabetes have type 1.
Type 2 diabetes occurs when the body does not make enough insulin and/or does not respond well to the insulin it makes. About 90% to 95% of people with diabetes have type 2. People are typically diagnosed with type 2 diabetes after the age of 40, although it is now also being seen in children and adolescents. This type of diabetes is associated with excess body weight, and in most people, is preventable by following a healthy meal plan, getting regular exercise, and maintaining healthy weight.
Gestational diabetes is a form of diabetes that develops in women during pregnancy and disappears after delivery. Gestational diabetes affects about 4% of all pregnant women and increases the risk of both the mother and the child developing type 2 diabetes.
Pre-diabetes is a key risk factor for type 2 diabetes. It is a risk condition where blood glucose levels are elevated, but not high enough for a diagnosis of diabetes. Pre-diabetes is diagnosed by measuring impaired fasting glucose or impaired glucose tolerance. Impaired fasting glucose pre-diabetes is associated with fasting blood glucose levels from 6.1 to 6.9mmol/L; impaired glucose tolerance is where blood glucose levels range from 7.8 to 11mmol/L after a 2-hour oral glucose tolerance test. In Canada, it is estimated that 4 million people between the ages of 40 and 74 have impaired fasting glucose and 1.8 million have impaired glucose tolerance.