Diabetes Mellitus

Epidemiological of Specific Chronic Diseases: Diabetes Mellitus

Description
Diabetes is a chronic condition that occurs when the Islets of Langerhans in the pancreas do not produce enough insulin or when the body cannot effectively use the insulin it produces.

There are two principal forms of diabetes:

Type 1 diabetes - in which pancreas fails to produce insulin. Usually has its onset in childhood and adolescence.

Type 2 diabetes - results from the body's inability to respond properly to the action of insulin produced by the pancreas.
Type 2 diabetes is more common and accounts for around 90% of all diabetes cases worldwide1.  Classically, with an onset later in life, Type 2 diabetes is increasingly being diagnosed in children and young people.

Gestational diabetes mellitus (GDM), develops during some pregnancies and may result in several adverse outcomes including congenital malformations, increased birth weight and an elevated risk of perinatal mortality. Metabolic control may reduce these risks to that of an non-diabetic expectant mother1.

Hyperglycaemia can lead to damage to many of the body's systems, especially the nerves and blood vessels.

Symptoms

Type 1 - commonly: polyuria, polydipsia, weight loss, blurred vision and fatigue.

Type 2 - symptoms may be less marked and is often diagnosed from complications.

An estimated 50% of individuals with diabetes are unaware of their condition.

Epidemiology

  • Worldwide approximately 170 million people have diabetes mellitus and it is estimated that this number may double by 20251.  Much of this increase will occur in developing countries.
  • There are an estimated 2.3 million people with diabetes in England. This is approximately 4% of the population.  The number of cases is expected to increase to over 2.5 million by 2010.
  • The NHS spends an estimated 5% of its budget on treating diabetes and its effects.
  • In the UK type 2 diabetes is up to 6 times more common in people of South Asian descent and up to 3 times more common in those of African and African-Caribbean descent.
  • Diabetes is a major risk factor for stroke, coronary heart disease, blindness and kidney failure.
  • Diabetic retinopathy is the leading cause of blindness and visual disability.
  • An estimated 80% of people with diabetes will die from cardiovascular disease.
  • Persons with diabetes are 2-3 times more likely to suffer a stroke.

Risk Factors

  • Family history - especially for type 2 diabetes
  • Age - increased with age more prevalent in those aged >45 years
  • Obesity
  • Sedentary lifestyle
  • Diet
  • Impaired glucose tolerance
  • Ethnicity
  • Hypertension
  • Raised serum lipids
  • Smoking
  • Certain genetic markers have been shown to increase the risk of developing Type 1 diabetes.

References

World Health Organization, Diabetes Fact Sheet No. 138. Available online:
http://www.who.int/mediacentre/factsheets/fs138/en/

© CM Kirwan 2006