What is diabetes?

Glucose is the body’s main energy source and is produced by the breakdown of carbohydrates from food intake as well as from stores within the body. Diabetes Mellitus, commonly referred to as ‘diabetes’, exists in two major forms: type 1 and type 2 diabetes.

Type 1 diabetes develops if the body is unable to produce any insulin, a hormone responsible for blood glucose control.

Type 2 diabetes develops when the body can still make some insulin, but not enough, or when the insulin that is produced does not work properly (known as insulin resistance).

If either type of diabetes is not managed carefully, the levels of blood glucose may remain unacceptably high and expose patients to the risk of serious complications. A vast increase in the number of people with diabetes is expected in many countries in the coming years. Most of these cases will be type 2 diabetes, which can be attributed to an ageing population and a dramatic increase in rates of obesity.

While there are a number of tests for diabetes, the two most common are the Fasting Plasma Glucose Test (FPGT) and and the Oral Glucose Tolerance Test (OGTT). The FPGT involves taking blood after a period of eight hours of fasting. If the concentration of sugar in the blood is higher than 7mmol/l then it is typically means that the patient is diabetic. The OGTT involves taking two blood samples over a period of two hours after a patient has fasted for eight hours and then ingested a pre-determined amount of glucose, normally in the form of a drink. If the level of glucose in the blood is in excess of 11.1mmol/l then this is usually indicative of diabetes.

The OGTT is the preferred test method of the World Health Organisation because it analyses a patient’s ability to metabolise glucose. While it tends to be less convenient than the FPGT, it does identify a number of pre-diabetes conditions such as Impaired Fasting Glycaemia and Impaired Glucose Tolerance, which can be treated to prevent or delay the onset of the disease.