Type 2 diabetes mellitus (known as type 2 diabetes) is a metabolic disorder in which the cells of the body become resistant to insulin and/or the pancreas doesn’t make enough insulin. Your body needs insulin to regulate the levels of sugar (glucose) in your bloodstream.
Type 2 diabetes often goes hand in hand with obesity, high blood pressure and high cholesterol. It is increasingly affecting younger people and some people with type 2 diabetes have to use insulin.
Type 2 diabetes often develops with no symptoms at all or the symptoms are so mild that they go unnoticed. For this reason, blood glucose testing is important because it can detect diabetes early and allow prompt treatment to prevent complications developing.
Diabetes symptoms may include:
- fatigue (tiredness);
- feeling abnormally thirsty;
- increasing hunger;
- increasing urination;
- blurred vision; and
- frequent infections and slow healing of sores or wounds.
What causes type 2 diabetes?
Type 2 diabetes doesn’t develop overnight. It usually begins with insulin resistance, where the body’s cells can’t use insulin properly. Glucose builds up in the bloodstream, and the pancreas keeps on producing insulin to try and get the blood glucose level down. Over time, the pancreas loses its ability to secrete enough insulin. This can eventually result in the person with type 2 diabetes having to inject insulin every day.
The good news is that because it doesn’t develop overnight, if people at risk of developing type 2 diabetes are identified early enough, they may be able to take measures to avoid it.
This is why having your blood glucose level tested is a good idea. A slightly raised blood glucose level that is above normal, but below the cut off point for a diabetes diagnosis, may be a sign of glucose intolerance or what doctors have named ‘pre-diabetes’. This puts you at risk of developing not only diabetes, but also heart disease.
Factors that increase a person’s risk of developing type 2 diabetes include:
- being older than 55;
- being overweight or obese;
- weight stored around the waist rather than the hips;
- having family history of diabetes;
- being inactive;
- being of Aboriginal or Torres Strait Island descent;
- being of Pacific Island, Asian or Indian subcontinent descent;
- being from the Middle East, Northern Africa or Southern Europe;
- having polycystic ovary syndrome;
- having had gestational diabetes while pregnant or having given birth to a baby that weighed more than 4.5 kg; and
- having pre-diabetes – blood glucose levels that are slightly raised but not high enough to diagnose diabetes.
Tests and diagnosis
Your doctor will ask about your symptoms and perform a physical examination.
Tests that can be used to confirm a diagnosis of diabetes include:
- Blood glucose level: a simple blood test that measures how much glucose is in the blood. It can be measured after a period of fasting or at a random time.
- Glycosylated haemoglobin (HbA1C) is a blood test that gives an indication of how high blood glucose levels have been over the previous 2 to 3 months.
- Oral glucose tolerance tests can be used when the diagnosis of diabetes is in doubt. Blood glucose levels are measured at certain times after you have consumed a drink containing a set amount of glucose.
You may be diagnosed with pre-diabetes if you have impaired (borderline) fasting glucose or impaired glucose tolerance.
If you are diagnosed with type 2 diabetes, your doctor will recommend blood tests at regular intervals to monitor your blood glucose control and to check for complications of diabetes.
Treatments for type 2 diabetes
Treatment for type 2 diabetes involves:
- control of blood glucose levels through lifestyle and medicines; and
- treatment of other conditions that increase cardiovascular risk.
The aim of treatment of type 2 diabetes is to prevent complications associated with diabetes (such as heart disease and kidney, eye and nerve problems). This involves controlling not only your blood glucose, but also your blood pressure and cholesterol. The first strategies to do this are usually lifestyle changes.
Healthy eating to control blood glucose levels
Your blood glucose is affected by:
- what you eat;
- when you eat it;
- how much you eat;
- how much exercise you do; and
- your medications or insulin.
Eating too much food can make your blood glucose go too high. Drinking alcohol without eating any food can make your blood glucose drop too low.
Ways that you can try to maintain a relatively stable and healthy blood glucose level are:
- eat at the same times each day;
- eat roughly the same amount of food each day;
- know which foods contain carbohydrates, fats and proteins;
- eat low-GI foods to keep your blood glucose levels down;
- eat carbohydrates at every meal to spread your intake;
- don’t miss meals or snacks;
- avoid high-sugar items, like lollies, soft drinks and desserts;
- exercise at roughly the same time each day;
- balance your food intake with your level of physical activity; and
- take medicines at the same time each day.
It is usually recommended that people with diabetes see a dietitian to develop a healthy eating plan that will help control blood glucose levels.
High-fibre, low GI carbohydrates are recommended for people with diabetes. Glycaemic index can be used as a guide in selecting carbohydrate foods.
Foods with low GI values are absorbed slowly and cause blood glucose levels to rise steadily. High GI value foods cause blood glucose levels to rise quickly. Eating low GI foods can help people with diabetes to avoid big peaks and troughs in blood glucose levels. Generally raw, unprocessed foods have a low GI and processed foods tend to be high GI foods.
Alcohol and blood sugar
Alcohol can both elevate and lower blood glucose levels.
- Alcoholic drinks are high in kilojoules as are many popular mixer drinks. As a result, alcoholic drinks can elevate blood sugar as well as contribute to weight gain and elevated blood pressure. It is preferable to choose low alcohol drinks (such as light beer) and low joule/diet mixers.
- Excessive alcohol in combination with insulin or oral diabetes medicines can also cause hypoglycaemia (low blood sugar). Hypoglycaemia can also result from drinking even small amounts of alcohol on an empty stomach, so if you drink alcohol, you should make sure you eat at the same time to reduce the risk of hypoglycaemia.
People with type 2 diabetes should limit their intake of alcohol to 2 standard drinks per day and aim for regular alcohol-free days.
Losing weight and/or maintaining a healthy weight
Among people with type 2 diabetes who are overweight, blood glucose control is improved by weight loss of just 5 to 10 per cent.
Regular physical activity
Regular physical activity can:
- improve blood glucose control;
- improve wellbeing;
- help with weight loss and weight maintenance; and
- improve cholesterol levels.
It has been shown that a combination of aerobic exercise and strength training can help control blood glucose more effectively than either type of exercise on its own. You should aim for about 30 minutes of exercise every day.
Check with your doctor before starting an exercise programme to ensure it is suitable for you.
It also important to stop smoking if you are a smoker.
If lifestyle measures aren’t enough, your doctor may recommend that you take tablets to lower your blood glucose.
The various types of medicines that lower blood glucose work in different ways.
- Biguanides (metformin) decrease the amount of glucose that your liver makes and releases.
- Sulfonylureas stimulate your pancreas to make more insulin.
- Thiazolidinediones (glitazones) make you more sensitive to insulin.
- Alpha-glucosidase inhibitors slow down the absorption of glucose or carbohydrates from your intestine.
- Incretin enhancers and mimetics (DPP-4 inhibitors and GLP-1 receptor agonists) stimulate the release of insulin and reduce the production of glucose by the liver.
- SGLT2 inhibitors prevent the reabsorption of glucose by the kidneys.
Your doctor may recommend that you take more than one type of tablet if one type alone does not reduce your blood glucose sufficiently.
Lifestyle measures remain essential, even once you have started on medicines. While blood sugar control does tend to worsen with time, you are much more likely to avoid eventually progressing to insulin therapy if you can maintain good eating and exercise habits.
In some cases your doctor may suggest that you take insulin. This will be if you are not getting good enough control with tablets and lifestyle measures alone. Many people with type 2 diabetes will eventually need to start taking insulin because their bodies will stop making it.
To avoid the complications of diabetes you may also need medicines to control your blood pressure and the amount of cholesterol and other lipids (types of fats) in your blood. The same lifestyle changes that are encouraged for diabetes can also help reduce your need for these extra medicines.