Non-diabetic hyperglycaemia (NDH) or prediabetes refers to blood glucose levels above the normal range but not sufficiently high for a diagnosis of diabetes (see Table 1). About 5 million people in England have NDH and are at high risk of developing type 2 diabetes. Every year 5-10 per cent will progress to diabetes but there is much pharmacists can do to help prevent or delay this.
 
This module uses the terms ‘prediabetes’ and ‘non-diabetic hyperglycaemia’ interchangeably because they are useful when explaining individual risk of developing type 2 diabetes to people. No stigma is implied with using these terms in explaining the risk.
 
There are no obvious symptoms or signs of prediabetes, so most people may not be aware they have an increased risk for diabetes, so it can remain ‘silent’ and undetected. The risk factors are the same as for type 2 diabetes: overweight, older age, poor diet and excess calories or poor nutrition, lack of physical activity, smoking and family history (see Table 2).
 
The risk of developing diabetes is seven times greater for people who are obese and three times greater for those who are overweight. Glycated haemoglobin (HbA1c) levels of 48mmol/mol (6.5 per cent) or above are suggestive of type 2 diabetes. There is no international consensus on a fixed cut-off for diagnosing prediabetes.

Key facts

• Prediabetes is where blood glucose levels are higher than normal but not high enough for a formal diagnosis of diabetes
• Around 5 million people in England have high blood glucose (prediabetes or non-diabetic hyperglycaemia), which places them at high risk of developing type 2 diabetes
• At least 5 per cent of UK health expenditure is spent on treating diabetes
• According to NICE, a fasting plasma glucose of 5.5-6.9mmol/L or HbA1c result of 42-47mmol/mol is indicative of prediabetes
• Lifestyle-related risk factors can be addressed in order to reverse prediabetes
• Being overweight or obese are strong risk factors for developing prediabetes or type 2 diabetes
• Engaging in exercise and fitness programmes, losing weight, and reducing fat and sugar in the diet can help to reverse prediabetes
• Metformin and orlistat can be used to support the management of prediabetes where necessary.