Type 1 diabetes

Previously known as insulin-dependent diabetes mellitus or juvenile diabetes

Type 1 diabetes is an autoimmune condition in which the body is unable to produce enough insulin, resulting in insulin deficiency.

Key points

  1. Insulin is a hormone made by the pancreas which helps control how much glucose, or sugar, is in the blood.
  2. Without insulin, too much glucose stays in your blood rather than passing into your body's cells to give them energy. 
  3. Long-term, high glucose levels causes damage to eyes, kidneys, blood vessels, our heart and feet. 
  4. One of the key aims of treatment for diabetes is to keep the glucose levels as close to normal throughout the day as possible. Doing this reduces the immediate risk from high or low glucose levels (hyperglycaemia and hypogylcaemia). 
  5. When well-managed, type 1 diabetes should not stop people from leading full and normal lives.

Insulin deficiency & type 1 diabetes

Insulin is a hormone that acts as a 'key' to move glucose, our body's energy building block, from the bloodstream into the body’s cells where it is used to provide energy. In type 1 diabetes, little or no insulin is made by the pancreas, so the glucose stays in your bloodstream giving you high blood glucose, or hyperglycaemia. Your cells become short of glucose, so they try to use fats to provide energy – this can lead to a dangerous build-up of waste products called ketones.

Ketones are a type of acid that is produced when the body burns fat for energy instead of glucose. This happens when there isn't enough glucose or insulin circulating in the bloodstream. Using fat for energy some of the time is normal. However, if it goes on for too long high levels of ketones in the bloodstream are dangerous and can lead to coma or even death.

Treating type 1 diabetes means replacing insulin to 'unlock' your cells, letting glucose in, and keeping your blood glucose level stable. Successful management of type 1 diabetes involves having insulin injections and balancing what you eat with how active you are each day. 

What are the causes of type 1 diabetes?

The exact cause of type 1 diabetes is unknown, but it is thought to be an autoimmune condition. In autoimmune conditions, our body's immune system is confused and attacks our own cells. In type 1 diabetes, the cells that are damaged are the beta cells in the pancreas that make insulin.

When first diagnosed with type 1 diabetes, a person may still be producing some insulin. Over time more insulin producing cells are damaged, until the body can no longer produce any of it's own.

Who is at risk of type 1 diabetes?

Only about 10% of all people with diabetes have type 1 diabetes. Type 1 diabetes is most common in children or young adults; however, it can occur at any age.

You have a slightly higher chance of developing type 1 diabetes if you have a closely related family member who also has it. This suggests that genetic factors may also play a part. 

What are the symptoms of type 1 diabetes?

Symptoms of type 1 diabetes are caused by high blood glucose levels (hyperglycaemia) and can come on very quickly. People can get quite sick when they first get type 1 diabetes and often need to be in hospital for a few days. Symptoms can include:

  • feeling very thirsty
  • having to pass urine a lot more than normal
  • no energy
  • blurred vision
  • rapid weight loss
  • sores that do not heal
  • recurring infection in the urinary system, vagina, mouth or throat
  • poor concentration and performance
  • feeling very hungry.

If a diagnosis is not made quickly, severe dehydration can occur.

What is the treatment for type 1 diabetes?

While there is no cure for diabetes, since the development of artificial insulin, type 1 diabetes can be well managed and controlled. The aim of treatment is to give the right amount in insulin to balance what you eat with how much energy you need throughout the day. Successful management of type 1 diabetes involves:

  • regularly testing your blood glucose level throughout the day
  • taking regular injections of insulin two or more times per day
  • eating regular meals and choosing healthy food
  • keeping physically active to keep your heart and blood vessels healthy
  • controlling blood pressure
  • keeping cholesterol levels down.

Self-care for type 1 diabetes

What do I need to do?

You can reduce any cardiovascular risk factors by working with your healthcare team (doctor, nurse or pharmacist) to:

  • keep your cholesterol down
  • keep your weight in a healthy range
  • control your blood pressure
  • stop smoking or remain smokefree
  • reduce salt in your diet
  • learn how to fine tune your insulin doses with different meal sizes and activity levels.

Managing low blood glucose (hypoglycaemia)

Although people with type 1 diabetes are trying to keep their blood glucose level from going too high, it is also important to stop it going too low. If the blood glucose drops below 4 mmol/L this is called low blood glucose or hypoglycaemia. This can be caused by, for example, injecting too much insulin or not eating enough of the right food at the right time.

Symptoms include sweating, shakiness, light-headedness, and can lead to unconsciousness if not treated. Low blood glucose must be raised urgently, with quick-acting carbohydrate such as glucose tablets (or glucagon injections if the person is unconscious).

Blood glucose testing

To test your blood glucose level throughout the day, we use a small finger prick test to obtain a drop of blood which can be put onto a testing strip. The testing strip is inserted into a blood glucose meter and gives a result within seconds.

  • A normal reading is between 4 to 7 mmol/L (glucose is measured in millimoles per litre of blood).
  • Check with your doctor, nurse or pharmacist what your target level should be.
  • If the level is below 4 mmol/L, you will usually need to eat something.
  • If the level is above 7 mmol/L, you may need to alter your insulin dose or do something active.
  • Learning how to balance these levels with what you eat, how much insulin you give yourself and how active you are key to managing your diabetes.

Healthy eating and exercise

We all need some carbohydrate foods. The important difference for people with diabetes is a greater need to balance what they eat with how active they are.

  • Choose healthier, high fibre carbohydrates eg wholegrain breads (breads with lots of ‘grainy’ bits), high-fibre breakfast cereals, legumes, fruit and vegetables and those with a low glycaemic index.
  • Carbohydrate foods with a low glycaemic index (low GI) are digested (broken down to glucose) more slowly.
  • This results in a more gradual rise in blood glucose levels, helping to give a more even blood glucose levels.
  • Eat breakfast, lunch and dinner at regular times of the day with snacks in between as advised by your dietitian or nurse.
  • Regular exercise is also essential to maintain a healthy blood glucose level.

Cut back on:

  • refined carbohydrates (cakes or pastries)
  • sweets, added sugar, and foods high in sugar
  • food that is high in fat are also best avoided.

Stress management and illness

Managing stress is especially important. Blood glucose levels are more difficult to control if you are under stress, so you may need to monitor them more frequently.

  • Make sure you know what to do when unwell and have a 'sick day' plan.
  • If you are vomiting or have diarrhoea, see a doctor for urgent medical help as the risk of dehydration is greater.

How do I prevent complications with type 1 diabetes?

In the long term, poor diabetes control increases the risk of serious complications such as:

  • problems with vision, or blindness
  • heart attack or stroke
  • kidney failure
  • circulatory problems, possibly leading to amputations
  • impotence in men.

With good control of your diabetes, many of these complications can be prevented or slowed down so make sure to have your regular check-ups with your doctor or nurse so that potential problems can be detected and treated early.

Support for type 1 diabetes

Most people cope well with support from health professionals, partners, family/whanau, diabetes support groups and diabetes educators. With a clear understanding of the condition, you can lead a normal, fulfilling life.

Kiwis living well with diabetes Diabetes NZ
Children with diabetes Diabetes Youth New Zealand

Regional diabetes support

Learn more

There is a wealth of information now about living well with diabetes. The following websites are places to start.

Living well with diabetes Diabetes New Zealand
Type 1 diabetes NHS Choices, UK
Diabetes Projects Trust

Credits: Health Navigator Team.