What is the difference between type 1 and type 2 diabetes?

There are three major types of diabetes: type 1, type 2, and gestational diabetes. All types of diabetes cause blood glucose levels to be higher than normal, but they do this in different ways

Type 1 diabetes

Type 1 diabetes can occur at any age, but is most commonly diagnosed from infancy to the late 30s. With this type of diabetes, a person’s pancreas produces no insulin. It occurs when the body’s own defence system (the immune system) attacks and destroys the insulin-producing cells in the pancreas. What causes the immune system to do this is not yet completely understood, but we are funding research to find out.

Type 2 diabetes

Type 2 diabetes is by far the most common type of diabetes – in the UK over 90 per cent of people with diabetes have type 2. Type 2 diabetes usually affects those over 40, or 25 if you’re of South Asian descent. However, it is becoming more common among young people due to lifestyle. The symptoms of type 2 diabetes are not always obvious and, unlike with type 1, they can take a long time to develop.

People with type 2 diabetes either don’t make enough insulin or don’t make insulin that the body can use properly. The cells in the body become resistant to insulin, making a greater amount of insulin necessary to keep blood glucose levels within a normal range. Eventually, the pancreas can wear out from producing extra insulin, and it may start making less and less.

Type 2 can usually be managed through diet, exercise, and self-monitoring blood glucose, at least in the first few years following diagnosis. However, type 2 diabetes is a progressive condition, and most people will need to take tablets and/or inject insulin after living with it for five to 10 years.

LADA

Up to a third of people who were initially diagnosed as having type 2 diabetes actually have latent autoimmune diabetes of adults (LADA), sometimes refer to as type 1.5. People with LADA have features of both type 1 and type 2 diabetes – their immune system attacks the cells of the pancreas that produce insulin, but they may also develop insulin resistance.

The destruction of the insulin producing cells is much slower in LADA than in type 1 diabetes. A blood test is needed to tell the difference between type 2 diabetes and LADA.

Some people can manage LADA on diet, exercise and tablets in the initial months or years following diagnosis. However, most with move onto insulin therapy at some point.

Gestational diabetes

Gestational diabetes usually only affects women during pregnancy. This type of diabetes affects about two to five per cent of pregnant women.

Pregnant women produce large amounts of hormones, which can cause the body to become resistant to the effects of insulin. By the time a woman reaches the end of the third trimester, her insulin requirements have tripled. If the pancreas is unable to match this increased demand, blood-glucose levels start to rise.

In most cases, blood glucose returns to normal after pregnancy. However, women who have had gestational diabetes have a higher risk of eventually developing type 2 diabetes.