What is type 1 diabetes?
Type 1 diabetes is one of the most common chronic diseases beginning in childhood and is becoming more common, with 100,000 Australians now depending on insulin injections every day to stay alive. Type 1 diabetes is due to a lack of the hormone, insulin, which is produced by cells in the pancreas called betacells. Without insulin, the body can’t use glucose, an important source of energy. The level of glucose in the blood then increases, causing symptoms such as thirst, frequent urination, dehydration weight loss and sometimes coma. When insulin is given regularly by injection the blood glucose levels can be controlled but are never perfectly normal. This sets the stage for longer- term complications involving blood vessels and nerves, leading to cardiovascular disease, blindness, kidney failure and other problems.
The diagnosis of type 1 diabetes signals a dramatic upheaval in the life of the child and the family. The child lacks the hormone, insulin, which controls the level of glucose in the body. Without injections of insulin, sometimes up to four times a day, the child will die. In addition, skin prick tests, to measure the level of sugar (glucose) in the blood, must be done several times a day to work out how much insulin to inject. In young children, the responsibility for doing this and keeping the child well usually falls to the mother. It places a terrible on burden on the family, day after day.
How does type 1 diabetes occur?
The insulin-producing beta cells are destroyed in type 1 diabetes because the body’s immune system starts attacking them as if they are foreign. Children who develop type 1 diabetes have a genetic susceptibility, but factors in the environment such as infections are also necessary to trigger the misdirected immune response against the beta cells.
Until the 1970s, we knew very little about how type 1 diabetes occurred. Most of what we know about this disease has been discovered by medical researchers in just the lastthree decades. Some of these discoveries have occurred in Australia. In the 1970s, researchers in Sydney discovered that women who contracted German measles (rubella) during pregnancy gave birth to children with a high risk of getting type 1 diabetes. Vaccination against rubella has put a stop to this, but there are obviously other important environmental factors because the incidence of the disease is not decreasing.
Recently, researchers in at the Walter and Eliza Hall Institute and Royal Melbourne Hospital discovered an important link with another virus called rotavirus. Rotavirus infection, the commonest cause of diarrhoea in infants, was found to be associated with the onset of the immune attack against the beta cells. The same researchers in Melbourne have identified genes that predispose to type 1 diabetes, identified chemicals from immune cells that kill the beta cells, developed tests that identify children likely to get type 1 diabetes and are now ready to conduct trials to prevent type 1 diabetes.
Can type 1 diabetes be prevented?
By understanding how the immune system kills the beta cells that make insulin, the Melbourne researchers have developed ways of preventing diabetes in a mouse model of the human disease. This milestone has lead to a vaccine that has recently undergone a successful pilot trial in children and adolescents who were at high risk for the disease. A large trial of this vaccine in many centres in Australia is now planned to determine if the vaccine will stop children at risk from becoming diabetic.
The researchers first need first to identify those at risk and estimate their chances of getting diabetes within a specified time. This is done by a simple blood test. However, for every 100 screened no more than three are likely to be eligible for the prevention trial. Many thousands of children and adolescents will have to be screened therefore to identify those at risk and eligible for the trial. This massive logistical exercise requires funding that falls outside the scope of available research funding.
Melbourne researchers are in a leading position to take up the challenge to prevent type 1 diabetes. The benefits to children and families would be inestimable.
Click here to visit the Clinical Trials page and find out how we are trying to prevent diabetes, or check out one of the links below to find out more about support and resources for people with type 1 diabetes
Diabetes Australia (Victoria) - this site contains research and clinical news on type 1 and type 2 diabetes with diet and lifestyle tips and is the home of one of the major Australian diabetes support groups.
The International Diabetes Institute - this site contains a wealth of information about type 1 diabetes, including current research, living with diabetes, diet and clinical information.
The American Diabetes Association - this is an overseas website, which focuses on living with diabetes, with information on weight loss and diet, sections for parents, children and doctors, and even recipes (although beware - all recipes are in Imperial measurements, so make sure you have a converter when baking).
