Type 1 is the least common of the 2 forms of diabetes and accounts for 5-15% of all people with diabetes.
Type 1 diabetes is an autoimmune disease in which there is partial or total failure of insulin production. The cause remains unknown but it may be triggered in genetically susceptible individuals. The disease usually develops suddenly in those under the age of 40 years. It always requires treatment with insulin.
Type 2 diabetes is more common than type 1 diabetes and accounts for at least 75% of cases. It results from a deficiency in insulin and/or a reduced sensitivity to insulin (insulin resistance); meaning the body’s cells do not respond to any insulin present and glucose remains in the blood. The development of type 2 diabetes is closely associated with obesity; with about 80% of people with the disease being overweight or obese. Diet and lifestyle measures may be sufficient to control type 2 diabetes, but most people will also require medication.
Both type 1 and type 2 diabetes are characterised by high blood sugar levels if not treated or poorly treated, as insulin controls the amount of sugar in the blood by moving it into the bodies cells where it can be used by the body for energy.
There are currently over 2 million people in the UK with diabetes and up to another 750, 000 who have the condition and don’t know it.
Interestingly type 2 diabetes is more common in people of South Asian and Afro-Caribbean origin.
Classic symptoms of diabetes include:
- Excessive urine production
- Unexplained weight loss
- Slow healing of wounds
- Extreme tiredness
- Blurred vision
Symptoms of type 1 diabetes are usually very obvious and develop quickly over a period of a few weeks.
Symptoms of type 2 diabetes are often less obvious and sometimes non existent to begin with. For this reason it is important for people who could be at risk to get tested, as early diagnosis and treatment is key to preventing serious health problems from developing.
- Hypoglycaemia: This can occur when blood sugar levels fall too low and may be caused by missing a meal, taking too much insulin, drinking alcohol without food or unplanned/ strenuous exercise. It can also occur for no particular reason.
Symptoms often include shaking, pounding heart, confusion and irritability.
- Diabetic ketoacidosis: This can occur when toxic substances called ketones build up in the body. They are produced when fat is used to make energy instead of sugar and are usually flushed straight out of the body in urine. If levels become too high ketoacidosis results and can cause breathlessness, nausea and vomiting, blurred vision and if left untreated can result in coma.
- Hyperosmolar non-ketotic acidosis: This ocurs in people with type 2 diabetes who may have very high blood sugar levels. It can develop over a course of weeks and symptoms can include frequent urination and great thirst, nausea, dry skin, disorientation and, in later stages, drowsiness and a gradual loss of consciousness.
- Cardiovascular disease: This includes heart disease, stroke and all other diseases of the heart and circulation, such as hardening and narrowing of the arteries supplying blood to the legs, which is known as peripheral vascular disease (PVD).
- Damage to eyes (retinopathy): Retinopathy affects the blood vessels supplying the retina in the eye. Blood vessels in the retina of the eye can become blocked, leaky or grow randomly. This damage gets in the way of the light passing through to the retina and if left untreated can damage vision.
- Neuropathy: Neuropathy causes damage to the nerves that transmit messages to and from the brain and spinal cord, to the muscles, skin, blood vessels and other organs.
- Kidney disease (nephropathy): Kidney disease can happen to anyone but it is much more common in people with diabetes and people with high blood pressure. Kidney disease in diabetes develops very slowly, over many years. It is most common in people who have had the condition for over 20 years.
Diagnosis of diabetes is made through the use of different blood glucose tests taken at different times during the day, and before and after food (or glucose tablets). The diagnostic criteria for diabetes have been defined by the World Health Organisation (WHO 1999).
A diagnosis of diabetes will be made if the following results are found:
- Random venous (from a vein) plasma glucose concentration of more than or equal to 11.1mmol/l
- Fasting plasma glucose concentration of more than or equal to 7mmol/l
- 2 hour plasma glucose concentration of more than or equal to 11.1 mmol/l 2 hours after 75g of glucose in an oral glucose tolerance test.
Ideal fasting blood glucose levels should be between 4-5 mmol/, and after a meal should be between 4 -7.7mmol/l.
A random sample should be less than or equal to 6 mmol/l.