Diabetes mellitus is a condition in which the amount of glucose (sugar) in the blood is too high because the body cannot use it properly. Glucose comes from the digestion of starchy foods such as bread, rice, potatoes, chapatis, yams and plantain, from sugar and other sweet foods, and from the liver which makes glucose.

Insulin is vital for life. It is a hormone produced by the pancreas, which helps the glucose to enter the cells where it is used as fuel by the body.

The main symptoms of untreated diabetes are increased thirst, going to the loo all the time (especially at night), extreme tiredness, weight loss, genital itching or regular episodes of thrush, and blurred vision.

Type 1 diabetes develops if the body is unable to produce any insulin. This type of diabetes usually appears before the age of forty. It is treated by insulin injections and diet.

Type 2 diabetes develops when the body can still make some insulin, but not enough, or when the insulin that is produced does not work properly (known as insulin resistance). This type of diabetes usually appears in people over the age of forty, though often appears before the age of forty in South Asian and African-Caribbean people. It is treated by diet alone or by diet and tablets or, sometimes, by diet and insulin injections.

The main aim of treatment of both types of diabetes is to achieve near normal blood glucose and blood pressure levels. This, together with a healthy lifestyle, will help to improve well being and protect against long-term damage to the eyes, kidneys, nerves, heart and major arteries.

Type 2 diabetes in children

The number of children developing Type 2 diabetes continues to rise and spread through all cultures as children become less active and more overweight.

Insulin resistance is strongly associated with obesity, so once the diagnosis has been made, referral to a registered dietitian and close monitoring by the healthcare team is necessary to give help to make the changes in lifestyle. It is very important that the whole family is involved as increasing the level of physical activity to the recommended one hour per day and a healthy eating plan are at the top of the list of changes that can make a big difference in managing weight control and achieving optimum blood glucose levels. Intake of saturated fats should be reduced and intake of fibre should be increased. Sometimes medication is necessary to help achieve blood glucose control too.

The importance of prevention of Type 2 diabetes in children cannot be overstated, as this is a chronic lifelong condition with the possibility of serious complications. The most effective prevention is to keep a child's weight at the right level for their height, the 'centile' lines can be found in the child's health record book and the family doctor or health visitor will be able to explain what these are. Active hobbies such as brisk walking, swimming and cycle riding should be encouraged as well as ones which do not involve too much physical exertion such as going for a stroll.

Families who are concerned about the risk of developing diabetes should talk to their GP for further advice and support.

Inheritance patterns
Both types of diabetes run in families and emerge in individuals in whom genetic susceptibility is triggered by environmental determinants. Genetic susceptibility to Type 1 resides largely in the genes encoding the HLA (human leukocyte antigen) molecules of the MHC (major histocompatibility complex) located on the short arm of chromosome 6. Relatives sharing these genes are more likely to develop Type 1 but even in identical twins, only about forty per cent share the disease. Type 1 occurs substantially more frequently in people of European than non-European origin, but its incidence varies greatly between national groups and over the course of time within them. Environmental trigger factors are uncertain.

Identical twins are much more likely both to have Type 2. No single genetic locus for susceptibility has yet been located though in rare subtypes of Type 2, occurring atypically in young people (Diabetes - Maturity Onset Diabetes of the Young), a clear pattern of Mendelian dominant inheritance is seen and, in some, the genetic variant characterised. Environmental determinants include increasing age, central obesity and physical inactivity. Some drugs may provoke glucose intolerance. Intrauterine and early life environment may 'programme' liability to diabetes in adult life.

Prenatal diagnosis
Inapplicable

Medical text written October 2000 by Diabetes UK. Approved October 2000 by Dr A C F Burden, Consultant Physician and Hon. Senior Lecturer, Chair of the Diabetes Care Advisory Committee of Diabetes UK, London, UK. Last updated August 2005 by Diabetes UK. Approved August 2005 by Dr R I G Holt, Senior Lecturer in Endocrinology and Metabolism, University of Southampton, Southampton, UK.

DIABETES UK

Diabetes UK
10 Parkway
London NW1 7AA
Tel: 0845 120 2960 Careline
Tel: 020 7424 1000
Fax: 020 7424 1001
e-mail: info@diabetes.org.uk
Web Site http://www.diabetes.org.uk

Formerly known as the British Diabetic Association, Diabetes UK is a National Registered Charity No. 215199, established in 1934 by Dr R D Lawrence and H G Wells. It offers a confidential help and support service for people with diabetes, their carers and health care professionals. It has a nationwide support network and funds research into diabetes. It campaigns for improvements for people who live with diabetes. It publishes: 'Link Up' a quarterly newsletter for parents; 'Tadpole Times' and 'On The Level' quarterly newsletters for children and teenagers with diabetes; 'Balance' a magazine published two monthly; 'Diabetic Medicine' a monthly publication for health care professionals containing research papers on diabetes; and 'Diabetes Update' a quarterly publication for health care professionals with an interest in diabetes. It also has a wide range of information available, details on request. Diabetes UK has around 200,000 members.

Group details last updated August 2007.