What is diabetes?
People with diabetes mellitus have a relative or total absence of insulin. Insulin is a hormone secreted by the beta cells of the islets of langerhans in the pancreas, a leaf shaped gland situated in the abdomen.
Insulin enables cells to use glucose for fuel and energy and is vital for controlling blood glucose levels. Diabetes UK has created an animation explaining how insulin works in the body, what happens in type 1 and type 2 diabetes and typical symptoms. See What is diabetes on the Diabetes UK website.
Types of diabetes
Diabetes presents in several different forms:
- type 1: formerly called insulin dependent diabetes
- type 2: formerly called non-insulin dependent diabetes. This accounts for about 90 per cent of cases worldwide
- gestational diabetes
- other specific types (World Health Organization 1999, pages 25-30).
Type 1 diabetes
Type 1 diabetes results from immunological selective beta cell destruction and people with this condition require insulin replacement by injection and are prone to ketoacidosis in a hyperglycaemic state.
"Type 1 includes those cases attributable to an autoimmune process, as well as those with beta cell destruction...for which neither aetiology nor pathogenesis is known (idiopathic)" (World Health Organization 1999, page 11).
Type 2 diabetes
Type 2 diabetes is a chronic, progressive disorder associated with 'defect(s) in insulin secretion almost always with a major contribution from insulin resistance' (World Health Organization 1999, page 11) and is a marker for cardiovascular disease.
Gestational diabetes
Carbohydrate intolerance of variable severity with onset and first recognition during pregnancy.
Mody
Mody stands for maturity onset diabetes of the young. It is not the same as type 2 diabetes in children, it is a genetic form of diabetes that passes down every generation. For further information, go to: Diabetesgenes.org.
Diabetes symptoms
These include:
- increased thirst (polydipsia)
- increased urine production (polyuria)
- unexplained weight loss
- unexplained fatigue
- blurred vision
- repeat episodes of genital itching or thrush
- slow healing of wounds.
Prediabetes
Prediabetes is when blood glucose level is higher than usual but not high enough to cause diabetes for example a person has impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT).
A position statement has been developed by Diabetes UK (2009b) in consultation with experts in the field as there are currently no UK-based guidelines for the management of this prediabetic state. The statement also presents the argument for clear acknowledgement and identification of prediabetes as a condition and discusses the evidence around the potential to delay type 2 diabetes in people with impaired glucose regulation (IGR). This may also help to prevent cardiovascular disease as cardiovascular complications are associated with type 2 diabetes. See: Diabetes UK Position statement: Impaired glucose regulation (IGR)/ Non-diabetic hyperglycaemia (NDH)/ Prediabetes.
References
Full details of the bracketed citation in the text above and, in many cases, links to the actual documents are available in the reference list within this resource. Go to the reference list.