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Diabetes Basics; Everything you

need to know

Get a clear understanding of diabetes fundamentals to take control of your health. We provide essential information that will help you navigate the basics of diabetes with confidence.

What is Diabetes?

1. Basic Overview:

Diabetes mellitus, or commonly known as diabetes, is a condition where there is too much glucose in the blood. The body can’t make insulin, enough insulin or is not effectively using the insulin it does make. Over time high glucose levels can damage blood vessels and nerves, resulting in long term health complications including heart, kidney, eye and foot damage.

Diabetes is a serious chronic condition that can affect the entire body. While there is currently no cure, you can live an enjoyable life by learning about the condition and effectively managing it.

There are three main types of diabetes:

Pre-diabetes may be diagnosed before it progresses to type 2 diabetes.

2. Symptoms:

In type 1 diabetes, symptoms are often sudden and can be life-threatening so it is usually diagnosed within hours or days.

In type 2 diabetes, many people have no symptoms at all, while other signs can go unnoticed being seen as part of ‘getting older’. By the time symptoms are noticed, complications of diabetes may already be present. Common symptoms include:

Note: This information is of a general nature only and should not be substituted for medical advice or used to alter medical therapy. It does not replace consultations with qualified healthcare professionals to meet your individual medical needs.

3. Diagnosis

Diabetes can only be diagnosed with a laboratory blood test ordered by your general practitioner or nurse practitioner. A finger prick test using a hand-held glucose meter cannot be used to diagnose diabetes.

There are different blood tests to diagnose diabetes:

  1. Glycated haemoglobin (HbA1c): this non-fasting test is a measure of your average blood glucose over the last two to three months. It is measured in percent (%) or mmol/mol (millimoles per mole). An HbA1c of 6.5% (48 mmol/mol) or more means diabetes is likely. Between 6.0% to 6.4% would indicate pre-diabetes.
  2. Fasting blood glucose: this test measures how much glucose is in your bloodstream at a certain time of day when you haven’t eaten for eight hours such as overnight. It is measured in mmol/L (millimoles per litre). A fasting blood glucose of 7.0 mmol/L or more would indicate diabetes is likely. Between 6.1 mmol/L and 6.9 mmol/L is likely pre-diabetes (also called impaired fasting glucose).
  3. Non-fasting (or random) blood glucose: this test measures how much glucose is in your bloodstream at a certain type of day if you haven’t been fasting or have eaten something recently. It is measured in mmol/L (millimoles per litre). A random (non-fasting) blood glucose of 11.1 mmol/L or more would indicate diabetes. Between 7.8 mmol/L and 11.0 mmol/L is likely pre-diabetes (also called impaired glucose tolerance).
  4. Oral glucose tolerance test (OGTT): this test combines a fasting and a non-fasting blood glucose test. After the fasting blood test, you will take a very sweet drink and your blood glucose will be tested at 1 hour and 2 hours. The results are in mmol/L (millimoles per litre). Diabetes is likely if your fasting level is 7.0mmol/L or above, or your 2-hour level is 11.1 mmol/L or above.

Your general practitioner may order a second blood test to confirm diabetes if you do not have symptoms.

Type 1 diabetes is usually confirmed with an extra blood test to check autoantibodies. These are the ‘defence’ proteins the immune system produces, which can stop the pancreas from making insulin. There are five known autoantibodies related to type 1 diabetes. If any of these are high, then that would confirm you have type 1 diabetes.

Type 1 Diabetes Overview:

1. What is Type 1 diabetes?

Type 1 diabetes is an autoimmune condition where the body’s own immune system is activated to destroy the beta cells in the pancreas which produce insulin. We do not know what causes this autoimmune reaction however environmental factors are thought to set off the process. Type 1 diabetes is not linked to modifiable lifestyle factors. Currently there is no cure and it is lifelong.

Type 1 diabetes:

  • Occurs when the pancreas does not produce insulin
  • Represents around 10 per cent of all cases of diabetes and is one of the most common chronic childhood conditions
  • In children, onset is usually abrupt and the symptoms obvious
  • In adults, onset is slower
  • Symptoms can include excessive thirst and urination, unexplained weight loss, weakness and fatigue and blurred vision
  • Is managed with insulin injections several times a day or the use of an insulin pump

2. What happens to the pancreas?

In type 1 diabetes, the pancreas, a large gland behind the stomach, stops making insulin because the beta cells that make the insulin have been destroyed by the body’s own immune system. Without insulin, glucose (a type of sugar) cannot enter the body’s cells where it is usually turned into energy.

People with type 1 diabetes depend on insulin every day of their lives to replace the insulin the body cannot produce. They must monitor their glucose levels throughout the day to ensure they stay within their target glucose range. This can be done using a blood glucose monitor or continuous glucose monitor. Type 1 diabetes can develop at any age.

3. What happens if people with type 1 diabetes don’t receive insulin?

Without insulin glucose builds up in the body. The kidneys attempt to wash the excess glucose out through the urine, resulting in dehydration. The body burns its own fat reserves to supply energy which releases chemical substances in the blood called ketone bodies. Without ongoing injections of insulin, these ketone bodies accumulate. The high glucose and ketone levels along with dehydration can be life threatening if it is not treated. This is a condition called diabetic ketoacidosis (DKA).

4. What causes type 1 diabetes?

The exact cause of type 1 diabetes is not known, but we do know it has a strong genetic link and cannot be prevented. People who develop diabetes may have one or a number of genes which make type 1 diabetes more likely, then some sort of environmental trigger occurs to start the autoimmune reaction. Examples of triggers include an infection or a high level of stress. Triggers are not always easy to identify.

Type 1 diabetes has nothing to do with lifestyle, although maintaining a healthy lifestyle is very important in helping to manage all types of diabetes, including type 1 diabetes. At this stage nothing can be done to prevent or cure type 1 diabetes.

5. Symptoms:

6. Management, care and treatment

Type 1 diabetes is managed with insulin injections several times a day or the use of an insulin pump.  Insulin can’t be taken as a tablet as it would be digested down to its building blocks, amino acids, by the body’s normal digestive process.

Glucose levels can be measured using a blood glucose monitor or a continuous glucose monitor which measures glucose in the body’s interstitial fluid.

Following Australia’s national guidelines on healthy eating and exercise applies to all Australians, including people living with type 1 diabetes. Learning to recognise and count carbohydrate will assist with your accurate dosing of insulin.

If you are very newly diagnosed with type 1 diabetes there is often a ‘honeymoon period’ after you begin taking insulin. This is where your body’s pancreas still produces some insulin, so your insulin needs may vary for a while. Eventually your pancreas will stop producing insulin completely.

Having a diabetes healthcare team who you can turn to for advice, support and treatment is recommended. These will include your general practitioner, endocrinologist, dietitian, diabetes educator, Diabetes Nurse Practitioner, podiatrist, exercise physiologist, and psychologist.

Type 2 Diabetes Overview:

1. What is type 2 diabetes?

Type 2 diabetes is a condition in which the body becomes resistant to the normal effects of insulin and gradually loses the capacity to produce enough insulin in the pancreas. The condition has strong genetic and family-related (non-modifiable) risk factors and is also often associated with modifiable lifestyle risk factors. We do not know the exact genetic causes of type 2 diabetes. People may be able to significantly slow or even stop the progression of the condition through changes to diet and increasing the amount of physical activity they do.

  • Is diagnosed when blood glucose levels are high due to insulin produced by the pancreas not working effectively and/or the cells of the body do not respond to insulin effectively (known as insulin resistance), over time the condition progresses and the pancreas does not produce enough insulin (reduced insulin production)
  • Represents 85–90 percent of all cases of diabetes
  • Usually develops in adults over the age of 45 years but is increasingly occurring in younger age groups including children, adolescents, and young adults
  • Is more likely in people with a family history of type 2 diabetes or from particular ethnic backgrounds
  • For some, the first sign may be a complication of diabetes such as a heart attack, vision problems or a wound that does not heal well
  • Is managed with a combination of regular physical activityhealthy eating, and weight reduction. As type 2 diabetes is progressive, many people will need oral medications and/or insulin injections in addition to lifestyle changes.

2. What happens with type 2 diabetes?

Type 2 diabetes develops over a period of time. During this time insulin resistance starts, this is where the insulin is increasingly ineffective at managing the blood glucose levels. As a result of this insulin resistance, the pancreas responds by producing greater and greater amounts of insulin, to try and achieve some degree of management of the blood glucose levels.

As insulin overproduction occurs over a very long period of time, the insulin-producing cells in the pancreas wear themselves out, so that by the time someone is diagnosed with type 2 diabetes, they have lost 50 – 70% of their insulin-producing cells. This means type 2 diabetes is a combination of ineffective insulin and not enough insulin. Lifestyle changes may be able to slow this process in some people.

Initially, type 2 diabetes can often be managed with healthy eating and regular physical activity. Over time many people with type 2 diabetes will also need tablets, and/or non-insulin injectable medications and many eventually require insulin injections. It is important to note that this is normal, and taking tablets, non-insulin injectable medications or insulin as soon as they are required can result in fewer long-term complications.

3. What causes type 2 diabetes?

Diabetes runs in the family. If you have a family member with diabetes, you have a genetic disposition to the condition.

While people may have a genetic disposition towards type 2 diabetes, the risk is greatly increased if people have a number of modifiable lifestyle factors including high blood pressure, being overweight, not being active enough, eating a poor diet and having the classic ‘apple shape’ body where extra weight is carried around the waist.

People are at a higher risk of type 2 diabetes if they:

  • Have a family history of diabetes
  • Are older (over 55 years of age) – the risk increases as we age
  • Are over 45 years of age and are overweight
  • Are over 45 years of age and have high blood pressure
  • Are over 35 years of age and are from an Aboriginal or Torres Strait Islander background
  • Are over 35 years of age and are from Pacific Island, Indian subcontinent or Chinese cultural background
  • Are a woman who has given birth to a child over 4.5 kgs (9 lbs), or had gestational diabetes when pregnant, or has a condition known as Polycystic Ovarian Syndrome (PCOS)
  • Have a mother who had gestational diabetes when they were in utero

4. Symptoms

Many people with type 2 diabetes have no symptoms. As type 2 diabetes is commonly (but not always) diagnosed at a later age, sometimes signs are dismissed as a part of ‘getting older’. In some cases, by the time type 2 diabetes is diagnosed, the long-term complications of diabetes may already be present.

5. Managing type 2 diabetes

While there is currently no cure for type 2 diabetes, the condition can be managed through lifestyle modifications and medication and in the early stage put onto remission. Effectively managing diabetes is the best way to prevent diabetes-related complications.

Blood Glucose Overview:

1. What is a normal blood glucose level?

For a person without diabetes, throughout the day blood glucose levels (BGLs) will generally range between 4.0 – 7.8 millimoles of glucose per litre of blood (mmols/L) regardless of how they eat or exercise, or what stress they’re under.

2. What should my BGL be?

When you’re living with diabetes your body cannot, or finds it hard to, keep your BGLs within a healthy range.

Because each person living with diabetes is different, your GP, NP, CDE, or specialist will set target BGLs that are right for you. The information below is a general guide for target blood glucose levels before meals and after eating.

3. Glucose level targets

Diabetes Targets
Target Blood Glucose Levels (BGLs) Before meals: 4.0 to 6.0mmol/L
2 hours after starting meals: 4.0 to 8.0mmol/L

4. What happens when my BGLs are outside of these ranges?

An important part of blood glucose monitoring is to identify hypoglycaemia and hyperglycaemia.

5. Inconsistent blood glucose levels

Sometimes you may get readings above or below your target range and you may not be able to figure out the reason. When you are sick or have an infection, your blood glucose levels may go up and you may need to contact your doctor. There are a number of other common causes for blood glucose levels to increase or decrease.

These include: 

  • Food – time eaten, type and amount of carbohydrate for example: bread, pasta, cereals, vegetables, fruit and milk
  • Exercise or physical activity
  • Illness and pain
  • Diabetes medication 
  • Alcohol
  • Emotional stress
  • Other medications
  • Blood glucose checking techniques.

Contact your doctor, NP or Credentialled Diabetes Educator if you notice that your blood glucose patterns change or are consistently out of your target range – above or below.

6. HbA1c – The big picture on blood glucose

Your GP, NP or specialist may request you to have a HbA1c (or glycated haemoglobin) blood test. This blood test provides an average measure of your blood glucose over the previous two to three months.

HbA1c is an important complement to self–monitoring at home (finger prick checks). Understanding your HbA1c levels can help you and your health care team make more informed decisions about your diabetes management. Some medications, treatments and inherited blood conditions can affect HbA1c results. Your doctor should be aware of your medical history to ensure an accurate HbA1c.

Your doctor will recommend a HbA1c target based on your individual circumstances. Usually this will be around 7% (53 mmol/mol).

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