High risk of type 2 diabetes

Being at high risk of type 2 diabetes is officially called non-diabetic hyperglycaemia or NDH. You may also have heard it referred to as borderline diabetes or impaired fasting glucose or impaired glucose tolerance. It means that the glucose levels in your blood are higher than normal, but not high enough for a diagnosis of type 2 diabetes.

Being diagnosed with non-diabetic hyperglycaemia puts you at high risk of developing type 2 diabetes in the future. The good news is that it is not inevitable that you will develop type 2, so by making some changes to your diet and lifestyle you can prevent or delay this from happening.

What causes NDH?

Foods that contain carbohydrate break down into glucose in the body and this is released into our bloodstream to be used as energy. In order for our body to use glucose, we need insulin, which is a hormone that is produced by our pancreas. When glucose levels in the blood increase, it signals to our pancreas to release insulin to help the glucose to get into your cells to be used for energy.

If you are at high risk of type 2, the cells in your body don't respond to insulin as they should. Your pancreas makes more insulin to try and get the cells to respond. Over time, your pancreas can't keep up and your blood glucose levels increase which leads to you becoming at high risk of type 2, and possibly type 2 diabetes if left untreated. 

Signs and symptoms

There aren't any symptoms when you are at high risk of type 2, but it is important to get tested if you are at risk to prevent long-term complications.

If you have any of the symptoms of type 2 diabetes then it is likely that sugar levels are high. You should get tested as you may already have type 2 diabetes.

Common symptoms of type 2 diabetes:

• going to the toilet more often, especially at night
• feeling more tired, because your body can't get enough glucose into your cells for energy
• losing weight without trying
• genital itching or thrush
• cuts and wounds taking longer to heal
• blurred vision
• feeling extremely thirsty

How is it diagnosed?

If you are at risk, your GP will usually carry out a blood test to look at glucose levels in your blood. Tests that are normally used include HbA1c, fasting blood glucose and an oral glucose tolerance test.

HbA1c

A HbA1c is a single blood test that shows your average blood glucose level over the last 8–12 weeks. A high HbA1c can represent a high risk of type 2 or type 2 diabetes.

Normal: HbA1c of less than 42

If your blood glucose levels are normal, that’s great! However, you may still be at risk of developing type 2 diabetes in the future. It’s important to eat healthily and keep active to help you aim for a healthy weight.

Higher than normal (non-diabetic hyperglycaemia): HbA1c between 42–47

If your blood glucose levels are higher than normal it means that you don’t have type 2 diabetes yet, but you’re at high risk of developing it. This can be referred to as non-diabetic hyperglycaemia. You should have a blood test once a year to monitor your glucose levels and should follow advice to prevent yourself from developing type 2 diabetes.

Here is a great online course to get you started. You may also be eligible for the national Healthier You programme. 

Type 2 diabetes: HbA1c over 48

If your test results suggest you have type 2 diabetes, you might be asked for another blood sample to confirm the result. The diagnosis can come as a shock but it’s important to remember that there is a lot of support available and that remission, where your blood glucose levels can return to a normal level without diabetes medications, is possible for some.

Our Know Diabetes site provides information, support and tools to help you manage type 2 diabetes

Fasting blood glucose

A single blood test is taken after a period of eating no food (fasting). A high fasting blood glucose level can represent a high risk of type 2 or type 2 diabetes.

Oral glucose tolerance test

An oral glucose tolerance test involves having your blood glucose measured after a period when you have not had any food or drink for 8 to 10 hours, usually first thing in the morning.

You will then be given a glucose drink and your blood glucose will be measured again usually after 2 hours. A high blood glucose level after 2 hours can be a sign of a high risk of type 2 or type 2 diabetes.