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Type 2 diabetes
Published by Bupa's health information team, July 2009.
This factsheet is for people who have type 2 diabetes, or who would like information about it.
Type 2 diabetes is a lifelong condition in which the body is unable to regulate the amount of glucose in the blood properly. It develops when the body doesn't respond to the natural hormone insulin, usually as a result of the person being overweight.
How type 2 diabetes develops
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About type 2 diabetes
Type 2 diabetes is also known as non-insulin-dependent diabetes mellitus.
Glucose and insulin
Glucose is a simple form of sugar found in foods and sugary drinks - it's absorbed as a natural part of digestion.
One function of your blood is to carry glucose around your body. When glucose reaches body tissues, such as muscle cells, it's absorbed and converted into energy. The glucose concentration in your blood is automatically regulated and insulin is crucial for this.
Insulin helps cells absorb glucose, where it's then converted into energy. Insulin is secreted into the blood by your pancreas - a gland found behind your stomach which also produces digestive juices. If your cells don't respond properly to insulin, this can cause glucose to build up in your blood. This is called insulin resistance. You become resistant to insulin if you're overweight or type 2 diabetes runs in your family. This means that your pancreas needs to produce more and more insulin to overcome the resistance and control blood glucose levels. Eventually your body can't produce enough insulin to control blood glucose so your levels rise and diabetes develops.
Pancreas and ducts
Types of diabetes
There are two main types of diabetes: type 1 and type 2.
There are about two million people in the UK who have diabetes. Type 2 diabetes is the common form, affecting nine out of every 10 people with diabetes.
Symptoms of type 2 diabetes
Many people with type 2 diabetes have no symptoms, and it's often discovered accidentally after routine medical check-ups or following screening tests for other conditions.
If you do have symptoms of type 2 diabetes, they might include:
- excessive passing of urine
- constant thirst
- blurred vision
- itchy skin around your genitals or regular infections, such as thrush
You may also have noticed a change in your weight over recent months. You may have gained some (causing diabetes) or lost some as a result of high blood glucose levels. It's also possible that your weight hasn't changed at all because of a combination of high blood glucose and a high calorie diet.
Your symptoms may be very mild and can go unnoticed for years.
Complications of type 2 diabetes
Long-term complications of type 2 diabetes are similar to those of type 1. These include:
- heart attack
- diabetic kidney damage
- diabetic foot ulcers or circulation problems in your legs and feet
- diabetic eye damage - if diagnosed and treated, blindness can usually be prevented
You will need to have annual check-ups to monitor whether you have developed any complications.
Rarely, if a severe infection occurs or type 2 diabetes isn't diagnosed or is poorly controlled, people with the condition can develop hyperosmotic non-ketotic coma (HONK).
HONK is caused if blood sugar levels rise to very high levels. It causes:
- extreme thirst
- feeling sick
- dry skin
- excessive urine production
Eventually it can cause drowsiness and loss of consciousness. HONK needs to be treated in hospital.
In the long term, uncontrolled high blood glucose (hyperglycaemia) can be very damaging to your health and can increase your risk of heart disease, stroke, kidney failure, nerve damage and blindness.
Causes of type 2 diabetes
Type 2 diabetes develops when your body becomes resistant to insulin. This happens when your body's tissues don't respond well to insulin and so can't make use of the glucose in the blood for energy. Your pancreas responds by producing more insulin and your liver, where glucose is stored, releases more glucose.
Eventually your pancreas becomes less able to produce enough insulin and your tissues become more resistant to insulin. As a result, blood glucose levels slowly start to rise.
It can take several years for blood glucose to reach a level that causes symptoms of type 2 diabetes.
You're more likely to develop type 2 diabetes if:
- you're overweight or obese - in particular, people who are an 'apple-shape' with lots of fat around the abdomen are more likely to develop diabetes
- you don't exercise very often
- type 2 diabetes runs in your family
- you smoke
- you drink alcohol excessively
- you're of African-Caribbean, South-Asian or Hispanic origin
- you're over 40 and caucasian - the risk increases further with age
- you have high blood pressure or have had a heart attack or stroke
- you have polycystic ovary syndrome and are overweight
- you have impaired glucose tolerance or impaired fasting glycaemia
Diagnosis of type 2 diabetes
If you think you may be developing diabetes, visit your GP. Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.
You may also be asked to have a blood test to measure the level of glucose in your blood. This might be a fasting glucose test, which is taken after you haven't eaten for at least eight hours, or a random glucose test done at any time.
If your GP can't make a definite diagnosis after these tests, you may have a glucose tolerance test. This measures how your blood glucose level changes over time after you swallow a sugary drink. You will need to fast overnight before having this test.
Your care will probably be managed by your GP. However, you may be referred to a hospital clinic that has nurses and doctors who specialise in diabetes.
Treatment of type 2 diabetes
Some people with type 2 diabetes can initially control their condition with lifestyle changes alone.
A healthy diet is essential if you have diabetes and it's important to eat regularly three times a day.
Special diabetic foods aren't necessary for a healthy diet; you just need to eat a balanced diet that is low in saturated fat, sugar and salt, and high in fibre, vegetables and fruit. Include carbohydrates, such as pasta, potatoes or sugary foods such as fruit in each meal.
Ask a dietitian at your GP surgery or hospital clinic for more information.
Exercise promotes a healthy circulation and will help you to stay a healthy weight. The Department of Health recommends that you do at least half an hour of moderate activity on at least five days a week.
Smoking is unhealthy for everyone, but it's especially important for people with diabetes to quit. This is because you already have an increased chance of developing cardiovascular disease or circulatory problems. Smoking makes the chances of developing these diseases even greater.
If you have diabetes, there's no need to give up alcohol completely, but it's important to drink sensibly. However, don't drink on an empty stomach - eat food containing carbohydrate before and after drinking and monitor your blood glucose levels regularly.
If lifestyle changes alone don't reduce your glucose levels, you may be prescribed medicines to increase insulin production and strengthen its effect. Some examples are listed here.
- Metformin is a medicine called a biguanide that improves the effectiveness of insulin by reducing the amount of glucose released from the liver and improving the way glucose is used by muscles.
- Sulphonylureas encourage your pancreas to produce more insulin, and include glibenclamide and glipizide.
- Prandial glucose regulators also encourage your pancreas to produce more insulin - they work more quickly than sulphonylureas but only last for a short time. Examples include repaglinide and nateglinide.
- Thiazolidinediones reduce your body's resistance to insulin and are sometimes used with metformin and sulphonylureas if other standard treatments aren't working or aren't tolerated. Examples include rosiglitazone and pioglitazone.
- Newer medicines called DPP-4 inhibitors, such as sitagliptin or vildagliptin, help your body to produce more insulin in response to meals. They don't cause weight gain and only rarely cause hypos.
- Acarbose lowers blood glucose by slowing the breakdown of some carbohydrates.
Two or more of the medicines listed here can be given in combination as they may give better control than one on its own.
Ask your doctor for advice on which medicine is best for you.
It's also possible that you will be given medicines to control your blood pressure if lifestyle changes including those mentioned above aren't enough to do this. Your GP will prescribe either an angiotensin converting enzyme (ACE) inhibitor, or an angiotensin II receptor blocker depending on which is most suitable for you.
It's also important to try to lower your cholesterol levels through lifestyle measures such as changing your diet, losing excess weight and taking regular exercise. However, if these don't work, you're likely to be prescribed a medicine to help lower your cholesterol. This will probably be a statin such as atorvastatin or fluvastatin.
It's very important to keep your blood pressure and the level of cholesterol in your blood well controlled. High blood pressure and high cholesterol levels have been linked to heart attack and stroke - you're more at risk of these and other complications if you have diabetes.
If lifestyle changes and medicines don't control your blood glucose levels, you may need to start insulin injections in addition to, or instead of, tablets.
You will usually give insulin injections to yourself once or twice a day, using either a traditional needle or a pen-type syringe with refillable cartridges. There are different kinds of insulin that work at different rates and for different lengths of time. Each can have varying rates of success in different people - ask your doctor for advice on which type is best for you.
Monitoring your blood sugar
You may be able to monitor your blood glucose levels with a home test kit. This involves taking a pinprick of blood from your finger and putting a drop on a testing strip. A meter will read the result automatically. However, self-monitoring isn't usually recommended unless you're using insulin injections. More research is needed to find out whether self-monitoring is an effective way of controlling blood glucose.
You can adjust both your diet and insulin to keep your blood glucose level within the normal range. Your 'normal' range will be specific to you but a general guide for adults is:
- before meals: 4 to 7mmols/litre
- after meals: less than 8.5mmols/litre
Your GP or specialist nurse can guide you on how to monitor and manage your blood glucose and will give you continuing support.
Type 2 diabetes Q&As
See our answers to common questions about type 2 diabetes, including:
- Diabetes. World Health Organization. www.who.int, accessed 11 February 2009
- National Collaborating Centre for Chronic Conditions. Type 2 diabetes: national clinical guideline for management in primary and secondary care (update). Royal College of Physicians, 2008. www.rcplondon.ac.uk
- NIDDM (type 2 diabetes). GP Notebook. www.gpnotebook.co.uk, accessed 12 February 2009
- Diabetes type 2. Clinical Knowledge Summaries. www.cks.library.nhs.uk, accessed 12 February 2009
- Hyperosmolar non-ketotic acidosis (HONK). Diabetes UK. www.diabetes.org.uk, accessed 12 February 2009
- Cardiovascular disease. Diabetes UK. www.diabetes.org.uk, accessed 11 February 2009
- Causes and risk factors. Diabetes UK. www.diabetes.org.uk, accessed 12 February 2009
- Types of diabetes. World Health Organization. www.who.int, accessed 11 February 2009
- Drugs used in diabetes. Joint Formulary Committee, British National Formulary. 56th ed. London: British Medical Association and Royal Pharmaceutical Society of Great Britain, 2008
- Definition and diagnosis of diabetes mellitus and intermediate hyperglycemia: report of a WHO/IDF consultation. World Health Organization, 2006.www.who.int
- 'Diabetic foods' and food labelling: Joint statement on 'diabetic foods' from the Food Standards Agency and Diabetes UK. Diabetes UK. www.diabetes.org.uk, accessed 11 February 2009
- CG66 Diabetes - type 2 (update). National Institute for Health and Clinical Excellence (NICE), www.nice.org.uk, December 2008
- Know your diabetes health numbers. Diabetes.co.uk. www.diabetes.co.uk, accessed 8 May 2009
- Diabetes and cholesterol. Diabetes.co.uk. www.diabetes.co.uk, accessed 8 May 2009
- Coster S, Gulliford MC, Seed PT, et al. Monitoring blood glucose control in diabetes mellitus: a systematic review. Health Technol Assess 2000; 4(12) www.hta.ac.uk
- Farmer AJ, Wade AN, French DP, et al. Blood glucose self-monitoring in type 2 diabetes: a randomised controlled trial. Health Technol Assess 2009; 13(15):1-50 www.ncchta.org
- Be active, be healthy: a plan for getting the nation moving. Department of Health. www.dh.gov.uk, 2009
- Smoking and diabetes. Diabetes UK. www.diabetes.org.uk, accessed 11 February 2009
- 10 steps to healthy eating. Diabetes UK. www.diabetes.org.uk, accessed 11 February 2009
- Treatments. Diabetes UK. www.diabetes.org.uk, accessed 11 February 2009
- Blood glucose. Diabetes UK. www.diabetes.org.uk, accessed 11 February 2009
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
Publication date: July 2009