What is type 1 diabetes?

Type 1 diabetes develops as a result of the pancreas creating very little or no insulin, leading to high blood glucose levels in the body. Type 1 diabetes is mostly diagnosed in childhood, but can occur at any age. It is thought to be due to an immune system problem, and there can be a genetic (inherited) component. People with type 1 diabetes need to inject insulin (under the skin) to regulate their blood glucose levels. Lifestyle measures such as healthy eating, exercise and managing stress are important in preventing long-term complications. Type 1 diabetes is also called ‘insulin-dependent diabetes mellitus’ (IDDM).

Why do our bodies need insulin?

Starchy and sweet foods are changed by the stomach into the sugar glucose, which enters the bloodstream. The hormone insulin, which is made in the pancreas gland, allows glucose to leave the bloodstream and enter 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 sugar’, 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 (ketones). Treating type 1 diabetes means replacing insulin to ‘unlock’ your cells (letting glucose in) and keeping your blood glucose level stable.

How common is type 1 diabetes?

It is estimated about 16,000 people in New Zealand have type 1 diabetes. It is usually diagnosed in children aged 7-12 years, but it can occur at any age. If you have a blood relative with diabetes you are more likely to develop type 1 diabetes. However, type 1 diabetes often occurs in people who have no one in their family with the condition.

What causes type 1 diabetes?

The exact cause is not known, but type 1 diabetes is called an 'auto-immune' condition. The body sets up an attack against the cells that produce insulin (called beta cells) in the pancreas. This auto-immune process happens over time. So, a person recently diagnosed with type 1 diabetes will usually still have some insulin being produced in their body, but, over time, their own insulin production becomes less and less, and eventually they will be producing none of their own insulin.

What are the symptoms?

Symptoms of type 1 diabetes are caused by high blood glucose levels (hyperglycaemia). Symptoms are often severe and generally lead to a quick diagnosis. They may include:

• extreme weight loss
• thirst, often extreme
• frequently passing urine
• tiredness
• blurred vision
• sores that do not heal
• recurring infection in the urinary system, vagina, mouth or throat.

Other possible symptoms include:

• abdominal pain, nausea, vomiting
• extreme hunger
• poor concentration and performance.

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

Ketones
If glucose levels are very high, a build-up of ketones is possible. Ketones are a type of acid and are produced when the body burns fat for energy instead of glucose, due to not enough insulin. We all break down fats for energy sometimes. Problems arise, however, if we break down a large amount of fat at any one time. Ketones can cause damage to the body if there are high levels in the blood. If left untreated, high ketone levels can lead to coma and, in extreme circumstances, death.

How is type 1 diabetes treated?

The aim of treatment is to control the level of glucose in the bloodstream. A personalised treatment plan is made, including:

• regularly testing your blood glucose level
• injections of insulin
• eating healthy food
• exercise
• stress management.

Other factors, such as keeping your weight and blood pressure in a healthy range, and not smoking, are also important in preventing complications. Learning more about diabetes will help you understand why certain measures will benefit your diabetes control and your long-term health.

Research continues into type 1 diabetes, but there is currently no cure. However, careful management allows you to lead a fulfilling life and to lower the risk of developing complications.

Blood glucose testing

Blood is self-tested on a daily basis, often several times a day before each meal. A small finger prick is used to obtain a blood droplet for the testing strip. The strip is measured using a blood glucose meter. A normal reading is 4 to 7 mmol/L (glucose measured in millimoles per litre of blood). Your specialist will advise if your target levels can be slightly higher than this. 

The test result will influence decisions about the amount and type of food you can eat, your insulin needs and the exercise you take. Your doctor or specialist will also arrange laboratory blood tests to give information about your overall control of blood glucose.

Insulin injections

Insulin injections are given just under the skin, with a tiny, short needle or a specially designed ‘pen’ injector. Insulin replacement is essential to the health of a person with type 1 diabetes. Insulin is available in many forms – the amount and the type of insulin(s) used and the timing of the injections will be advised by your doctor or diabetes specialist.

Healthy eating and exercise

Most carbohydrate foods are good for people with diabetes but those rich in fibre such as wholegrain breads (breads with lots of ‘grainy’ bits), high-fibre breakfast cereals, legumes, fruit and vegetables and those with a low glycaemic index are better. Carbohydrate foods that have a low glycaemic index (low GI) are more slowly digested and produce a more gradual rise in blood glucose levels, helping to sustain more steady blood glucose levels.

Refined carbohydrates (cakes or pastries), sweets and food that is high in fat should preferably all be avoided, or only consumed in small amounts on an occasional basis.

A regular eating pattern is also necessary. You will usually need to have snacks inbetween the three main meals - follow the advice of your dietitian on this.

Regular exercise is also essential to maintain a healthy blood glucose level.

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. If you are ill, it is extremely important that you maintain your insulin regime and carbohydrate intake. If you vomit more than once, seek medical help urgently.

What are the risks of type 1 diabetes?

In the long term, uncontrolled or untreated diabetes increases the risk of serious complications:

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

Some of these diabetes complications are irreversible but the risks can all be greatly reduced with having good control of your diabetes, following healthy lifestyle measures, and having regular check-ups so that potential problems can be detected and treated early.

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). See Hypoglycaemia for more information.

How do people cope?

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.

Original material provided by Diabetes New Zealand, 2008. Edited by everybody, August 2011.