Type 1 diabetes occurs when an individual does not produce any insulin; insulin is the hormone which controls blood glucose levels. Insulin is produced by the pancreas; when you eat, it is released into the bloodstream, where it takes glucose out of the blood and takes it to the cells to use for energy. People with type 1 diabetes do not produce insulin, which means that the glucose is not taken out of the bloodstream and delivered to the cells. Type 1 diabetes is sometimes known as juvenile diabetes or teenage diabetes because it usually develops in younger people.
It is not fully understood why some people do not produce insulin but scientists believe that type 1 diabetes is a form of autoimmune condition, which means that the body’s immune system mistakes a harmless substance or trigger for something harmful and starts to attack it. In the case of type 1 diabetes, the immune system starts to attack the cells in the pancreas that are responsible for producing insulin; this means that they are no longer able to produce insulin. It is not known what triggers the autoimmune response but there is some evidence to suggest that viral infections can sometimes trigger the response.
Type 1 diabetes also tends to run in families so genetics play a part; if you have a close relative with type 1 diabetes, there is a 6 percent chance of developing the condition.
In rare cases, type 1 diabetes may be caused by pancreatitis, a condition which occurs when the pancreas becomes inflamed.
Causes of type 2 diabetes
The exact cause of type 2 diabetes is not yet fully understood; however, a number of risk factors have been identified; these include:
? Age: risk increases after the age of 40
? Race and heritage: people who are Asian are most likely to develop type 2 diabetes; type 2 diabetes is six times more common amongst Asian people than white people in the UK. People with Middle-Eastern and African-Caribbean heritage are also more likely to develop type 2 diabetes; they are 3 times more likely to develop the condition than white people.
? Being overweight or obese. Waist size is particularly important; women with a waist measurement of over 31.5 inches and men with a waist measurement of over 35 inches if they are Asian or 37 inches if they are white or black. Losing even 5 percent of your bodyweight can reduce your chance of developing type 2 diabetes by up to 50 percent. You can assess your risk of developing type 2 diabetes by measuring your waist and calculating your BMI (sometimes the BMI result is not very accurate; for example, professional rugby players may be very fit and healthy but their BMI will be higher than the recommended range because they have a lot of muscle).
? Family history: you are more likely to develop type 2 diabetes if you have a close relative with the condition.
? High blood pressure: if you have high blood pressure or you have had a stroke or a heart attack, you are more likely to develop type 2 diabetes.
? Impaired glucose tolerance: if you have been diagnosed with impaired glucose tolerance or impaired fasting glycaemia, this may be an early sign of type 2 diabetes.
? Gestational diabetes: some women develop diabetes during pregnancy; if this is the case, they will be more likely to develop type 2 diabetes later in life.