Autoimmune disease
A disorder where the body's immune system behaves abnormally and starts attacking its own cells
Digestive system
The organ system in the body which breaks down large insoluble food molecules into small soluble molecules which can be used by the body
Type 1 diabetes
Develops when the body does not produce the right amount of insulin or, in some cases, does not produce any at all. It must be treated with daily injections of insulin. People affected also need to manage their diet, eat regularly and plan exercise carefully to balance their energy needs with their food and insulin intake.
Type 2 diabetes
The pancreas does produce insulin but cells stop responding properly to the insulin. It is often linked to obesity and lack of exercise and taking more exercise, losing weight and eating a carefully balanced diet can often control or even reverse type 2 diabetes.
Endocrine gland
A gland which secretes hormones straight into the bloodstream rather into the blood via a tube or duct.
Exocrine cells
Cells found in the exocrine glands that secrete hormones into ducts, as opposed to straight into the bloodstream.
Immune system
The body's natural defence mechanism against infectious diseases.
Blood sugar
The sugar (glucose) dissolved in the blood; the normal range is 4.0 - 7.8 mmol/l
Triglycerides
The most common lipid found in nature and consists of a single glycerol molecule bonded to three fatty acids.
Fatty acid
Large molecule consisting of a carboxylic acid (RCOOH) with the 'R' being a long unbranched hydrocarbon chain.
Receptors
Protein molecules attached to cells that only bind to specific molecules with a particular structure
Duodenum
Within the human body this is the first 25-30cm long section of the small intestine.
Glycogen
A polysaccharide, (C6H10O5)n, that is stored in the liver and in muscles and can be converted back into glucose when needed by the body.
Obesity
A disorder where an excessive amount of fat has accumulated in the body. It results when the energy taken in as food is stored in the body instead of being used up through activity
Enzyme
Reusable protein molecules which act as biological catalysts, changing the rate of chemical reactions in the body without being affected themselves
Starch
A complex carbohydrate made as an energy store plants
Cell
The basic unit from which all living organisms are built up, consisting of a cell membrane surrounding cytoplasm and a nucleus.
Liver
A large organ in the upper abdomen which manufactures, stores and breaks down substances as required by the body
Fibre
Material which cannot be digested in the gut, needed to provide bulk which enables food to move through the digestive system.
Urine
The liquid which leaves your body through the urethra. It contains water, salts urea and other chemicals.
Type 1 and Type 2 diabetes
There are approximately 180 million people worldwide who have diabetes and 2.5 million of these live in the UK. Up to one in five people with diabetes are unaware that they have the condition.
Diabetes can be successfully managed, but it is a chronic disorder which currently does not have a cure. It has several long-term health effects. This is especially true if blood glucose levels are poorly controlled in an individual.
Type 1 diabetes
Type 1 diabetes is an autoimmune disease and accounts for up to 10% of diabetes cases in the UK. It typically develops before the age of 40 and occurs when the pancreas can no longer produce insulin.
There are two types of cells in the pancreas. Exocrine cells are responsible for the production and secretion of digestive enzymes. These pass along the pancreatic duct into the duodenum. These cells are not usually affected in diabetes.
The pancreas also contains groups of cells called the islets of Langerhans. These cells release their products directly into the blood and so are a form of endocrine gland. Two hormones are produced in these islets. Insulin is made in beta cells and glucagon in alpha cells.
Type 1 diabetes develops when the person's own immune system destroys the beta cells. As a result insulin is no longer produced and blood sugar levels rise. This leads to the rapid onset of the symptoms of diabetes, including fatigue, unquenchable thirst, weight loss and the production of large volumes of urine.
The risk of developing type 1 diabetes has recently been linked with genetic factors and may be associated with lifestyle factors such as diet and exercise.
Type 1 diabetes is treated by insulin injections alongside a healthy diet and regular exercise. People with type 1 diabetes are usually required to take either two or four injections of insulin every day. These injections of insulin are vital to keep these people alive.
Type 2 diabetes
Type 2 diabetes is a disorder that is increasing in both developed and developing nations as unhealthy diets and lifestyles become more common. It 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). In most cases this is linked with the person being overweight. Type 2 diabetes usually occurs in people over the age of 40. In South Asian and African-Caribbean people it often appears after the age of 25. Recently more children are being diagnosed with the condition. Type 2 diabetes is more common than type 1 diabetes accounting for 85-95% of people with diabetes.
Many factors influence the development of type 2 diabetes; such as an inherited predisposition to diabetes and diets high in saturated fats, sugar and low in fibre. Being overweight also increases the chance of developing type 2 diabetes. Abdominal fat cells release fatty acids into the blood that stimulate the liver to release glucose and triglycerides. This process is therefore increased in overweight people with greater numbers of abdominal fat cells. Over a long period, muscles become insensitive to insulin and beta cells are destroyed.
Diabetes is increasing in developed nations. Obesity is linked with an increased risk of type 2 diabetes
Courtesy of: Anthea Sieveking / Wellcome Images
Obesity causes raised fatty acid levels which can cause diabetes
Type 2 diabetes accounts for around 90% of cases in the UK. It typically develops in the over 40's and can be treated using combinations of lifestyle changes (diet and exercise), oral medicines and daily, long acting, insulin injections.
Healthy diet
- Regular meals with foods that contain starch (bread, pasta, potatoes and rice) and decreased consumption of processed foods to maintain a stable blood sugar level.
- Reduced consumption of sugary foods like carbonated drinks, cakes and sweets.
- If overweight/obese, losing weight will help to control the disorder.
Medicines
- Bind to receptors on beta cells and stimulate the release of insulin.
- Sensitize the liver, fat and muscle cells to the insulin that is available.
- Reduce the breakdown of glycogen into glucose in the liver.
- Enzyme-inhibitors slow the breakdown of complex carbohydrates in the digestive system.
Regular exercise
- Helps the body to regulate its blood glucose levels.
- Helps to maintain a healthy weight.
- Improves blood pressure and lessens the chances of circulation problems.
Recent research has shown that it is possible to prevent diabetes in some people who are at high risk of developing the disease. For example, individuals in the Finnish Diabetes Prevention Study took part in an intensive lifestyle programme focussed on changing diet and physical activity behaviour. Over four years, these individuals were 60% less likely to develop diabetes than individuals who did not take part in the programme.
Question 1
