What is type 3c diabetes?

Introduction

Type 3c diabetes is diabetes that is caused by damage to the pancreas. It is sometimes known as “pancreatic diabetes”, “pancreatogenic diabetes” or “secondary diabetes”. The pancreas usually produces hormones to control blood sugar (insulin and glucagon) and the enzymes or digestive juices needed to digest food. If the pancreas is damaged, it produces less of the hormones and digestive juices causing problems with both digestion and blood sugars.

How does Type 3c diabetes differ from other types of diabetes?

• Type 1 Diabetes: People with type 1 diabetes produce very little or no insulin because the immune system (normally there to fight infection) attacks the insulin producing cells in the pancreas. People with type 3c diabetes produce less of all the hormones from the pancreas, including insulin and glucagon, because of the damage to the pancreas tissue.
• Type 2 Diabetes: People with type 2 diabetes can’t properly use the insulin their pancreas produces. This is called insulin resistance. The main problem in type 3c diabetes is producing too little insulin rather than insulin resistance

It can be difficult to be sure what sort of diabetes a person has, particularly when the diagnosis is first made.

What causes type 3c diabetes?

The most common conditions that cause diabetes by damaging the pancreas are:

• Acute pancreatitis - Acute pancreatitis is a condition where the pancreas becomes inflamed (swollen) over a short period of time.
• Chronic pancreatitis - Chronic pancreatitis is a condition where the pancreas has become permanently damaged from inflammation and stops working properly.
• Cancer of the pancreas
• Surgery of the pancreas
• Cystic fibrosis - Cystic fibrosis is an inherited condition that causes sticky mucus to build up in the lungs and digestive system. This causes lung infections and problems with digesting food.
• Haemochromatosis - Haemochromatosis is an inherited condition where iron levels in the body slowly build up over many years.

What are the symptoms of Type 3c diabetes?

If you have type 3c diabetes you may have symptoms due to:

• Diabetes such as:
  • Thirsty
  • Peeing a lot
  • Tiredness
  • Blurred vision
  • Repeated episodes of thrush
• Digestive problems such as:
  • Stomach pain
  • Bloating
  • Loose bowel motions or diarrhoea
  • Losing weight without trying
  • Low blood sugars
• Symptoms of the cause of the damage to the pancreas.

How is type 3c diabetes diagnosed?

If you have been diagnosed with diabetes and your healthcare team thinks you might have type 3c, they will ask you to provide a stool sample to look into whether you have problems with digestion.

You may also need a scan of the pancreas to look for a cause of type 3c diabetes and a blood test for antibodies to rule out type 1 diabetes.

How is it type 3c diabetes treated?

The aims of treatment are to control blood sugars and also make sure that food is digested and absorbed.

Enzyme replacement

Most people need to take enzyme tablets such as Creon, Nutrizym, Pancrease or Pancrex to help digest food. Getting the dose right can take time and a bit of trial and error. The usual starting dose is one tablet with a snack and two tablets with a main meal. Some people need much higher doses. The dose is right when the symptoms (eg loose motions, stomach ache and bloating) have settled down and weight loss stops.

Diet

Getting the diet right helps relieve symptoms and control blood sugars. The diet suggested for people with type 3c diabetes is similar to the diet for everyone with diabetes but with a few small changes. Many people with type 3c diabetes find it helpful to see a dietician for detailed advice. The main principles are:

• Meals
  • Eat regular, small meals
  • Do not skip meals
  • Eat mainly starchy carbohydrates
  • Reduce the amount of high-sugar/ high-glycaemic index food or fluids
• Enzyme therapy – needs to be taken with the first mouthful of all meals and snacks.
• Alcohol – should be avoided as type 3c diabetes is often caused by or made worse by alcohol

Some people also need to take regular vitamin supplements. Your healthcare team will advise if this is necessary.

Blood sugar control

The lack of both insulin and glucagon as well as the issues around food digestion can make controlling blood sugars difficult for people with type 3c diabetes. Getting the diet right is critical, but the majority of people with type 3c diabetes also need medication.

Medication

The amount and type of medication someone might need will depend on how much of the pancreas is still working. This varies a lot, so there is no standard treatment pathway that everyone follows. The medications that are used are:

1. Metformin – metformin improves the way the body responds to insulin. It can be useful at an early stage for people with type 3c diabetes who are still producing some insulin.
2. Sulphonylureas- sulphonylureas work by causing the pancreas to produce more insulin. They can also be useful at an early stage, although they can cause low blood sugar (hypoglycaemia).
3. Insulin – insulin is often needed at an earlier stage compared to type 2 diabetes. Insulin can also cause hypoglycaemia.

Hypoglycaemia

Hypoglycaemia can be a challenge for people with type 3c diabetes because the damaged pancreas may not be able to make the hormone glucagon. Glucagon raises blood sugar by releasing glucose that is stored in the liver. It is one of a number of hormones that will help bring blood sugar back up naturally in anyone with hypoglycaemia.

Hypoglycaemia can be avoided by getting the diet right, taking medication correctly and careful monitoring of blood glucose. Knowing how to treat hypoglycaemia is important. Advice on hypoglycaemia treatment can be found here.

Monitoring blood sugars

The majority of people with type 3c diabetes should monitor their blood glucose because of the difficulty with getting the blood sugars right and the risk of hypoglycaemia. You can monitor your blood glucose levels through a finger-prick check or by using continuous glucose monitoring (CGM). Your healthcare team will advise on whether you need to monitor and how to do so.

Useful Resources

Diabetes UK - https://www.diabetes.org.uk/diabetes-the-basics/type-3c-diabetes