What is type 1 diabetes?

Type 1 diabetes is a chronic autoimmune disease that can develop at any age. There is nothing anyone can do to prevent T1D, and right now there is no known cure.

Read on to find out more about type 1 diabetes (also known as T1D, juvenile diabetes, type 1 diabetes mellitus or insulin-dependent diabetes), including how it’s diagnosed and how it’s different from other types of diabetes.

Type 1 diabetes definition

When someone develops type 1 diabetes, the immune system mistakenly attacks the body’s own cells instead of defending against foreign invaders. In this case, the immune system attacks the beta cells in the pancreas, which produce insulin. Insulin is a hormone that converts glucose from food into energy for the body. Without enough insulin, glucose accumulates in the bloodstream, leading to diabetic ketoacidosis (DKA), a dangerous condition.

Type 1 diabetes is a lifelong condition, and there can be a risk of complications if blood glucose levels (BGLs) are not kept within the optimal range using various management strategies. Some of these deep and long-lasting impacts include:

• kidney damage
• eye damage
• nerve damage to feet
• gum and tooth disease
• sexual dysfunction in both men and women
• damage to the nerves that control internal organ functions such as digestion, bowel function, blood pressure, and heart rate.

Because their bodies can’t produce their own insulin, people with type 1 diabetes have to take insulin every day to make sure their body gets enough of it. They can do this through daily injections or by using an insulin pump. By managing their blood glucose levels, people living with type 1 diabetes can stay healthy and reduce the risk of complications.

It’s a challenging condition, but with treatment and management, people living with type 1 diabetes can live full and happy lives. Read stories from some of our community members who are living and thriving with type 1 diabetes.

Is type 1 diabetes an autoimmune disease?

When our body detects a microbial infection, it responds by causing inflammation. This helps our immune system fight the infection, and eventually that inflammation will go down once the infection has been resolved. However, if our immune system mistakenly attacks healthy cells or tissues, it can be the cause of inflammation and lead to autoimmunity. 

In type 1 diabetes, the immune system will mistakenly attack the beta cells in the pancreas. The antibodies that target the beta cells are called anti-islet autoantibodies, and can be detected in blood tests before any symptoms of diabetes start to appear. The presence of these autoantibodies is often used as a way to predict whether someone is at risk of developing type 1 diabetes in the future.

As people living with type 1 diabetes already have an autoimmune condition attacking their beta cells, their immune system is more likely to attack other cells or tissues. That means they’re more likely to also have conditions like coeliac disease and thyroid disease. In fact, it’s estimated that more than 90% of people with type 1 diabetes and another autoimmune disease also have autoimmune thyroid disease.

How common is type 1 diabetes?

Approximately 8.7 million people around the world live with type 1 diabetes. More than 130,000 of those people live in Australia, and eight more Australians are diagnosed each day.

People under the age of 30 are most commonly diagnosed with type 1 diabetes, but it can actually develop at any age. In fact, around half of all diagnoses in Australia are adults.

Taking a closer look at the prevalence of type 1 diabetes in Australia, the National (insulin-treated) Diabetes Register (NDR) found:

• a similar amount of males and females are living with type 1 diabetes
• Indigenous children and young adults have a 20% lower likelihood of living with type 1 diabetes when compared to their non-Indigenous peers
• the occurrence of type 1 diabetes in children and young adults varies depending on their socioeconomic status; the rates were found to be 1.2 times higher among those living in the most disadvantaged areas compared to the least disadvantaged areas.

What other types of diabetes are there?

There are about 422 million people living with diabetes internationally. Type 1 diabetes accounts for around 10% of all cases, with the remaining 90% living with type 2 diabetes, LADA or gestational diabetes.

Type 2 diabetes

People with type 2 diabetes develop insulin resistance, meaning their body doesn’t use insulin as well as it should. In later stages of type 2 diabetes, people may also not produce enough insulin.

Type 2 diabetes is caused by a combination of genetics and lifestyle factors, such as being overweight or having a sedentary lifestyle. It can often be managed by diet changes, exercise and medication. However, it is a progressive condition, and some people may need to inject insulin in the later stages of the disease.

LADA

Some people who were initially diagnosed as having type 2 diabetes actually have latent autoimmune diabetes of adults (LADA).  This is sometimes referred to as type 1.5 diabetes.

People with LADA have features of both type 1 and type 2 diabetes in that their immune system attacks the cells of the pancreas that produce insulin, but they may also have insulin resistance. The destruction of the insulin producing cells is much slower in LADA than in type 1 diabetes.

For some people, LADA can be managed with diet, exercise and medication. However, most people with LADA will require insulin therapy within the first year.

Gestational diabetes

Gestational diabetes refers to diabetes that is first detected during pregnancy. Pregnant women produce large amounts of hormones such as oestrogen and progesterone, which can cause the body to become resistant to the effects of insulin.

By the time a woman reaches the end of the third trimester, her insulin requirements have tripled. If the pancreas is unable to match this increased demand, blood glucose levels start to rise. In general, blood glucose returns to normal after pregnancy. However, women diagnosed with this type of diabetes are at significantly higher risk of developing type 2 diabetes later in life.