Humans need energy to fuel our bodies. Most of this fuel is glucose (sugar) which comes from the food and drinks we consume. Glucose needs to enter body cells through a glucose transporter or door. Insulin is the hormone that acts as a key to open the cell door and allow glucose to enter and provide the energy needed to survive. Without insulin, glucose builds up in the blood whilst the cells are unable to access the energy needed.

Type 1 diabetes (T1D) is a lifelong autoimmune condition in which the body's immune system mistakenly attacks and destroys the insulin producing beta cells in the pancreas.^4,6 As the beta cells are destroyed, the pancreas produces progressively less insulin until little to none is available.

Without insulin treatment, blood glucose levels rise and the body begins to break down fat as an alternative energy source, producing ketones. Ketones are an acid, and if untreated, the acid builds up leading to a life-threatening emergency called diabetic ketoacidosis (DKA).^1,3 High blood glucose levels over time can damage the body and increase the risk of diabetes complications to the eyes, kidneys, feet, heart and brain.

Although there is currently no cure for T1D, insulin therapy and technologies allow people with diabetes to live a long and healthy life.⁵ Recently immune therapies have been approved to treat at risk people and slow the development of T1D.⁹

To understand Type 1 diabetes, it helps to understand how the body normally uses glucose.

After you eat, carbohydrates are broken down into glucose, which enters your bloodstream. As blood glucose levels rise, the pancreas releases insulin.

Insulin allows glucose to move from the bloodstream into muscle, fat and many other body tissues where it is used to create energy. Insulin also tells the liver to stop releasing stored glucose into the bloodstream, helping keep blood glucose levels within a healthy range.

This process happens continuously throughout the day, even while you sleep.

The pancreas is an organ located behind the stomach in the upper abdomen. It has two important jobs.

The first is producing digestive enzymes that help break down food. The second is producing hormones that regulate blood glucose, including:

• • insulin
• • glucagon.

Insulin is produced by specialised cells called beta cells, which are found in tiny clusters known as the islets of Langerhans. Although these cells make up only a small part of the pancreas, they play a vital role in keeping the body healthy.

In people with Type 1 diabetes, the immune system mistakenly identifies the beta cells as "non-self". Instead of protecting the body from infection, immune cells gradually destroy these healthy insulin-producing cells.^6,7

Scientists believe this process develops because of a combination of genetic susceptibility and environmental factors, although the exact cause remains unknown.

As more beta cells are destroyed:

• • less insulin is produced
• • blood glucose levels begin to rise
• • the body's cells become starved of energy
• • the liver releases more glucose into the bloodstream
• • fat is broken down to provide energy
• • ketones are produced.

Eventually, there is too little insulin to keep blood glucose levels within a healthy range, and the symptoms of diabetes become obvious.

Insulin is often described as a "key", but it does much more than simply unlock cells. Insulin helps:

• • move glucose into cells
• • prevent excessive glucose production by the liver
• • store excess glucose for future use
• • regulate fat metabolism
• • prevent excessive ketone production
• • support normal growth and tissue repair.

Without insulin, the body's metabolism becomes severely disrupted. Even though glucose is abundant in the bloodstream, the body's cells cannot use it efficiently. This explains why people with untreated Type 1 diabetes may experience severe tiredness despite having very high blood glucose levels.

When the body cannot use glucose for energy, it begins breaking down fat instead. This process produces chemicals called ketones.

Small amounts of ketones are normal during fasting or prolonged exercise. However, when insulin is absent, ketones can build up rapidly, causing the blood to become acidic. This condition is called diabetic ketoacidosis (DKA).

Type 1 diabetes can develop at any age. Although it is commonly diagnosed in children, teenagers and young adults, many people are diagnosed later in life.^2,4

Adults can develop Type 1 diabetes in their 30s, 40s, 50s or beyond. Because many people associate diabetes in adults with Type 2 diabetes, diagnosis may sometimes be delayed.

Recognising the symptoms early is important because untreated Type 1 diabetes can become life-threatening.

Genetics play a role, but most people diagnosed with Type 1 diabetes do not have a close family member with the condition.

Having a parent or sibling with Type 1 diabetes increases the risk, but the overall chance of developing the condition remains relatively low.

Researchers believe that environmental factors trigger the autoimmune process in people who are genetically susceptible. Exactly which triggers are involved is still being investigated.

No.

One of the most common myths is that eating too much sugar causes Type 1 diabetes. This is incorrect. Type 1 diabetes is an autoimmune disease.

Current scientific evidence shows it is not caused by:

• • eating sugar
• • eating too many carbohydrates
• • being overweight
• • lack of exercise
• • poor parenting
• • stress alone.

Nothing that a person or parent did caused the immune system to attack the insulin-producing cells.

At present, there is no cure for Type 1 diabetes. Researchers around the world are investigating treatments including:

• • immunotherapy
• • beta-cell replacement
• • stem cell therapy
• • islet transplantation
• • gene-based therapies.

These areas of research are promising, but insulin replacement remains the essential treatment for everyone living with Type 1 diabetes.

Immune therapy has been approved by the TGA to delay the onset of Type 1 diabetes in people with very early (Stage 2) Type 1 diabetes.⁹

Yes.

Although Type 1 diabetes requires daily management, advances in treatment have transformed the outlook for people living with the condition. Many people now use:

• • continuous glucose monitors (CGMs)
• • insulin pumps
• • automated insulin delivery systems
• • smart insulin pens
• • smartphone apps to help manage diabetes.

People with Type 1 diabetes can:

• • work in almost any profession
• • travel internationally
• • compete in elite sport
• • have healthy pregnancies
• • raise families
• • live into older age.

Successful diabetes management involves learning how food, exercise, illness, stress and insulin affect blood glucose levels. With education and support, diabetes becomes something people manage every day rather than something that defines who they are.

If you have recently been diagnosed with Type 1 diabetes, it is normal to feel overwhelmed. Managing diabetes involves learning new skills, including monitoring blood glucose, taking insulin, recognising low and high blood glucose levels, and understanding how food and activity affect your body.

Although this may seem daunting at first, most people gradually develop confidence through education, practice and support from their healthcare team.

Today's diabetes technology and treatment options provide more flexibility, better glucose control and improved quality of life than ever before.