Diabetes type2 - Causes of type 2 diabetes

Insulin is a hormone that is needed to control the amount of glucose, a type of sugar, in your blood. When you eat, your digestive system breaks down your food to release the nutrients from it. These nutrients, including glucose, enter your bloodstream. Normally, insulin is produced by your pancreas to move the glucose from your blood into your cells, where it is broken down to produce energy.

Type 2 diabetes occurs because your body cannot produce enough insulin or because the cells in your body do not react properly to insulin.

Risk factors for type 2 diabetes

The exact cause of type 2 diabetes is not fully understood, although there are many factors that make developing the condition more likely. You are more likely to develop type 2 diabetes if:

• You have a relative with type 2 diabetes.
• You are of South Asian, African-Caribbean or Middle Eastern descent.
• You are overweight or obese.
• You are over 40.

Genetic factors

You are more likely to get type 2 diabetes if you have a close relative, such as a parent, brother or sister, who has it. The closer the relative, the greater the risk.

Ethnic origin

People of South Asian, African, African-Caribbean and Middle Eastern descent are more likely to develop type 2 diabetes. Type 2 diabetes is up to six times more common in South Asian communities than in the general UK population and three times more common among people of African and African-Caribbean origin.

People of African-Caribbean or South Asian origin are also more likely to develop complications of diabetes, such as heart disease, at a younger age than the rest of the population.

Being overweight or obese

If you are overweight or obese, you are at greater risk of developing type 2 diabetes. Fat around your abdomen (belly), sometimes called active fat, puts you at greater risk of type 2 diabetes than fat elsewhere. This is because it releases chemicals that can upset the cardiovascular and metabolic systems of the body. This can put you at higher risk of a number of conditions including heart disease, stroke and some cancers.

A quick way to assess your diabetes risk is to measure your waist. This is a measure of abdominal obesity, a particularly high-risk form of obesity. When you have excess weight around your middle, you are at high risk of developing diabetes.

Women are thought to be at a higher risk of developing type 2 diabetes if they have a waist size of 31.5 inches (80cm) or over. Men are thought to be at a higher risk if they are Asian and their waist is 35 inches (90cm) or over, or if they are white or black with a waist size of 37 inches (94cm) or over.

If you lose about 5% of your body weight and take regular exercise, you could reduce your risk of getting diabetes by over 50%.

Age

Your risk of developing type 2 diabetes also increases as you get older. This may be because people usually gain weight and exercise less as they get older.