Insulin & types of diabetes (summary)

Insulin is an important hormone that is made in the pancreas. The pancreas is an organ that sits behind the stomach. Insulin is made by islet beta cells in the pancreas.

Insulin has several important roles in the body:

• It controls how the body uses and stores glucose
• It controls how the body uses and stores fat.

Cells in your body use insulin to take sugar (glucose) out of the blood for energy.

If cells have enough energy, the liver takes the extra sugar out of the blood. It stores the excess glucose as glycogen in the liver cells. The liver can store around 5% of its weight as glycogen.

Insulin can be thought of as a ‘key’ that unlocks the door into cells. If the insulin ‘key’ works in the lock, the door will open. This means that glucose will move from the blood into your cells. The cells then use the glucose for energy.

People with Type 1 diabetes do not produce insulin. They do not have the ‘key’ to the door in the cells that allows the glucose to be absorbed. This causes blood sugar levels to rise.

In people with Type 2 diabetes, excess fat can clog up the locks. This means the insulin ‘keys’ do not fit the locks as well as they should. This means fewer doors into the cells open. This causes the blood glucose levels to rise. When this happens, a person is said to have ‘insulin resistance’.

The pancreas responds to insulin resistance by making more insulin ‘keys'. This is to try and lower the blood glucose levels by allowing more cell ‘doors’ to open.

Over time, insulin resistance can cause the pancreas to become worn out through overwork. This means it makes less insulin. When this happens, a person is said to have ‘insulin deficiency’.