Diabetes - Type 1
Type 1 diabetes affects over 140 000 children and adults in Australia and over 16 million people worldwide. This type of diabetes usually develops in people under 30 but can start at any age. It affects both sexes equally. Half of people with Type 1 diabetes are diagnosed before their 18th birthday. Around one in every 700 Australian children has Type 1 diabetes, which makes it one of the most common serious diseases amongst children.
People with Type 1 diabetes produce very little or no insulin. Insulin is the hormone that decreases blood glucose (sugar), which is a major fuel source for our bodies. Insulin is only produced by specific cells in the pancreas called beta cells. The release of insulin from the beta cells is mainly triggered by a rise in blood glucose, for example following a meal. Insulin then travels through the blood and helps to get glucose from the blood into cells where it can be used as a source of energy. Without insulin, blood sugar levels rise to dangerously high levels that can cause organ damage.
Life expectancy for patients with Type 1 diabetes changed significantly following the discovery of insulin in the 1920s. However, people with diabetes still have to monitor their blood sugar levels and take insulin by injection several times a day. Nevertheless, life expectancy is still decreased in people with Type 1 diabetes. It is thought that some people diagnosed before the age of 30 years may still lose more than ten years of life expectancy, although people with Type 1 diabetes can now live into their 90s or past 100.
What causes Type 1 diabetes?
Type 1 diabetes develops when the beta cells that make insulin have been destroyed by the body’s own immune system. This type of diabetes, in contrast to Type II diabetes where the beta cells are normally preserved, can therefore be classified as an autoimmune disease.
We are still not sure why this attack on the beta cells occurs, although we do know that it is caused by an interaction between genes and the environment. There is a genetic risk for Type 1 diabetes, although 80% of people with Type 1 diabetes have no family history of the disease.
What are the signs and symptoms?
The symptoms of diabetes include:
- Excessive thirst
- Frequent urination (including through the night)
- Hunger or loss of appetite
- Unexplained weight loss
- Fatigue, tiredness, nausea and vomiting
- Itching skin, thrush or other skin infections
- Visual disturbances, such as blurred vision
Uncontrolled diabetes can severely damage many systems, organs and tissues of the body. Even with insulin treatment, a lifetime of diabetes can result in serious long term consequences. Complications include kidney damage; increased likelihood of infections, such as thrush; damage to the eyes (diabetic retinopathy and cataracts); poor blood circulation in the legs and feet, sometimes requiring arterial grafts or even leading to lower limb amputation; damage to the nerves of the feet and hands; increased likelihood of heart disease and stroke; problems with pregnancy, and problems with sexual function.
What approaches to treatment are available?
Despite extensive ongoing research, at this stage nothing can be done to prevent or completely cure Type 1 diabetes, but the condition can be successfully managed.
- Self-monitoring of blood glucose levels by regularly testing droplets of blood in a glucose meter
- If glucose levels are high, self-testing to check for ketones in urine or blood
- Taking regular insulin injections
- Increasing the amount of ‘slow’ carbohydrates in the diet, such as beans and fruit, which take longer to be absorbed by the body (low GI foods)
- Regular exercise
- Regular medical checks, including eye checks
What research is Garvan doing in this area?
Garvan’s Immunology Division has several teams of scientists who are researching different aspects of Type 1 diabetes. The first priority is to understand how and why an immune system turns on itself and destroys the insulin-producing beta cells in the pancreas with the aim of trying to create new beta cells from other cell types.
This has led to the discovery of key factors that switch on the immune attack on the beta cells. This line of research is now focused on identifying compounds to block these factors with a view to preventing progression of diabetes in its early stages.
The second priority is a joint venture between Garvan and other centres aimed at taking the transplantation of pancreatic islets from an experimental procedure to a viable clinical option for people with diabetes. To date, the focus of our scientists has been on developing tests to monitor the recipient’s immune system for signs of rejection and finding markers to predict, before transplantation, how the islets will function after transplant - that is, to identify a molecular signature for a successful graft.
Please help us continue our groundbreaking work into Type 1 diabetes