Diabetes is a chronic condition where a person has high blood glucose (sometimes called blood sugar) levels. For our bodies to work properly we need to convert glucose (sugar) from food into energy.
To understand diabetes, it’s helpful to understand the basics of how your body metabolises (breaks down) blood glucose. Most of the cells in your body need glucose as a source of energy. When you eat carbohydrate, such as a bowl of cereal, pasta or fruit, your digestive system breaks down the carbohydrates into glucose (simple sugars), which travel through your blood stream to energise cells.
Insulin is released by the beta cells in response to the rise in blood glucose levels after eating. Insulin directs the glucose into the liver and muscle cells, promoting the storage of nutrients and preventing your blood glucose levels to rise excessively. Insulin also increases the uptake of amino acids (building blocks of protein) and fatty acids (building blocks of fats) into protein and fat stores. Insulin is therefore important for regulating metabolism by promoting energy storage and cell growth.
The liver converts glucose that is not needed immediately for energy into glycogen (which is stored in the liver). When blood glucose levels drop too low, insulin secretion falls and your pancreas releases the hormone glucagon, which prompts your liver to reconvert stored glycogen into glucose and release into the bloodstream. A normal functioning pancreas ensures there is a staple supply of nutrients for your body. This is important for certain organs such as your brain which depend on a steady supply of glucose.
In people with diabetes, insulin is no longer produced or not produced in sufficient amounts by the body. Instead of being turned into energy the glucose stays in the blood resulting in high blood glucose levels. After eating, the glucose is carried xaround your body in your blood. Your blood glucose level is called glycaemia.
In a person who is overweight or obese, the cells of the body become less responsive to insulin, which in turn causes the body to secrete more insulin to maintain normal metabolism. The pancreas would usually try and compensate for this resistance by pumping out more insulin, for most people with insulin resistance, blood glucose levels stay within a normal range. But for some people, the insulin producing cells fail to keep up with this demand with blood glucose levels rising and resulting in Type 2 diabetes. (In Type 1 Diabetes, the person’s immune system attacks and destroys the insulin-producing cells in the pancreas.
While there is currently no cure for diabetes, you can live an enjoyable life by learning about the condition and effectively managing it. Blood glucose levels can be monitored and managed through self-care, lifestyle changes and treatment.
The main types of diabetes include:
Type 1: Occurs when the immune system mistakenly attacks and kills the beta cells of the pancreas. No, or very little, insulin is released into the body. As a result, blood glucose builds up in the blood instead of being used as energy. About five to 10 per cent of people with diabetes have type 1 diabetes. Type 1 diabetes generally develops in childhood or adolescence, but can develop in adulthood.
Type 1 diabetes is always treated with insulin. Meal planning also helps with keeping blood glucose at the right levels.
Type 2: A progressive condition in which the body becomes resistant to the normal effects of insulin and/or gradually loses the capacity to produce enough insulin in the pancreas. Type 2 diabetes is one of the major consequences of the obesity epidemic. The combination of significant changes to diet and the food supply, combined with changes to physical activity with more sedentary work and less activity, means most populations around the world are seeing more type 2 diabetes. Type 2 diabetes also has strong genetic and family related risk factors. Type 2 diabetes accounts for 85% of all diabetes and is increasing.
Gestational (sometimes referred to as GDM): A temporary condition that is diagnosed when higher than normal blood glucose levels first appear during pregnancy. It affects approximately five to ten per cent of all pregnancies. When the pregnancy is over and blood glucose levels return to normal the diabetes disappears, however this insulin resistance increases the risk of developing type 2 diabetes in later life. Gestational diabetes in pregnancy is increasing.
Pre-diabetes: A condition in which blood glucose levels are higher than normal, although not high enough to be diagnosed with type 2 diabetes. Pre-diabetes has no signs or symptoms. People with pre-diabetes have a higher risk of developing type 2 diabetes and cardiovascular (heart and circulation) disease. Without sustained lifestyle changes, including healthy eating, increased activity and losing weight, approximately one in three people with pre-diabetes will go onto developing type 2 diabetes.
Can Type 2 diabetes be avoided?
Being diagnosed with impaired glucose metabolism doesn’t mean that you will get type 2 diabetes but you are at a 10-20 times greater risk than those with normal blood glucose levels. Strong evidence shows that type 2 diabetes can be prevented in up to 58% of cases in the high risk (pre-diabetes) population by eating well and exercising.
For more information on the types of diabetes please refer to Diabetes Australia