How to Treat Prediabetes: NHS Options

How to treat prediabetes is an important question for the growing number of people in the UK identified with non-diabetic hyperglycaemia (NDH). Prediabetes describes blood glucose levels that are higher than normal but below the threshold for type 2 diabetes, and without action, it can progress to a formal diagnosis. The good news is that targeted lifestyle changes, and in some cases medication, can significantly reduce that risk. This article explains how prediabetes is diagnosed in the UK, what treatments the NHS recommends, the risks of leaving it unmanaged, and the blood glucose levels you should aim for.

What is prediabetes and how is it diagnosed in the UK?

Prediabetes, known clinically as non-diabetic hyperglycaemia, is diagnosed in the UK using an HbA1c of 42 to 47 mmol/mol or a fasting plasma glucose of 5.5 to 6.9 mmol/l, typically identified through a GP blood test or NHS Health Check.

Prediabetes, more commonly referred to in UK clinical practice as non-diabetic hyperglycaemia (NDH), is a condition in which blood glucose levels are higher than normal but not yet high enough to meet the diagnostic threshold for type 2 diabetes. It is identified through specific blood test results rather than symptoms alone.

The NHS uses two main measurements for risk identification. According to NICE guidance (PH38) and UKHSA risk-identification criteria, an HbA1c of 42 to 47 mmol/mol (6.0% to 6.4%) indicates a high risk of developing type 2 diabetes and falls within the NDH range. A fasting plasma glucose of 5.5 to 6.9 mmol/l is also used to identify elevated risk. These are risk-identification cut-offs rather than a formal disease diagnosis in the way type 2 diabetes is diagnosed.

In some UK settings, an oral glucose tolerance test (OGTT) may be used, where a 2-hour plasma glucose result of 7.8 to 11.0 mmol/l indicates impaired glucose tolerance (IGT). This approach is less commonly used in routine UK primary care, where HbA1c is preferred because it does not require fasting.

Identification is typically made through a blood test arranged by a GP, often following a routine NHS Health Check or investigation of risk factors. The Healthier You: NHS Diabetes Prevention Programme (NHS DPP) is an intervention service, not a screening programme; it accepts referrals based on risk identification carried out elsewhere, such as through a GP surgery or NHS Health Check, and provides structured lifestyle support to those identified as being at high risk.

NDH does not always cause noticeable symptoms. However, if you experience significant thirst, passing urine more frequently than usual, unexplained weight loss, or extreme tiredness, contact your GP the same day or call NHS 111, as these may indicate a more advanced problem requiring prompt assessment. If you receive a result in the NDH range without such symptoms, your GP will discuss what this means for you and recommend appropriate next steps.

Which medicines does the NHS use to treat prediabetes?

Lifestyle modification is the primary NHS treatment for prediabetes; metformin may be considered off-label by a GP for selected high-risk individuals who have not responded adequately to lifestyle changes.

Lifestyle modification, rather than medication, is the primary treatment recommended by NICE (PH38) for non-diabetic hyperglycaemia.^[1][2] Adults identified with NDH should be referred to an intensive lifestyle programme such as the Healthier You: NHS Diabetes Prevention Programme, which focuses on dietary change, increased physical activity, and weight management.

Metformin, a biguanide that reduces hepatic glucose production and improves insulin sensitivity, may be considered by a GP for people with NDH who are at very high risk of progression to type 2 diabetes and who have not responded adequately to lifestyle intervention. NICE PH38 notes that typical groups who may be considered include those with a BMI of 35 kg/m2 or above, those with a rising HbA1c despite lifestyle changes, and those with a history of gestational diabetes. Its use in this context is off-label in the UK, meaning it is used outside its formally licensed indication. When metformin is considered off-label, the prescriber should explain this to the patient and document the clinical rationale; prescribing decisions are made on an individual basis following shared decision-making.

Other glucose-lowering medicines licensed for type 2 diabetes or weight management are not recommended by NICE for treating non-diabetic hyperglycaemia itself. It is worth clarifying the distinction between available agents: Wegovy (semaglutide) and Mounjaro (tirzepatide) are licensed in the UK for chronic weight management in adults with obesity or overweight with weight-related comorbidities, under separate NICE technology appraisals and commissioning pathways.^[11][12] Ozempic (semaglutide) is licensed for type 2 diabetes and is not licensed for weight management. None of these agents are recommended for treating NDH as a primary indication. Where a person with NDH also has obesity, weight-management options may be discussed separately with a clinician under the relevant NICE guidance.

Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support, where clinically appropriate options may be discussed following assessment.

If you are concerned about your blood glucose levels or feel your current management is not working, speak to your GP before making any changes to your treatment.

What are the risks if prediabetes is left untreated?

Untreated non-diabetic hyperglycaemia significantly increases the risk of progressing to type 2 diabetes and is associated with early cardiovascular changes, including increased risk of heart attack, stroke, and kidney disease.

Non-diabetic hyperglycaemia that is not addressed through lifestyle change or medical management carries a significant risk of progressing to type 2 diabetes, along with an increased risk of cardiovascular disease. The landmark Diabetes Prevention Program trial (Knowler et al., NEJM 2002) demonstrated that without intervention, a substantial proportion of people with impaired glucose tolerance or impaired fasting glucose will develop type 2 diabetes within several years, though this risk is not inevitable and can be meaningfully reduced.

Beyond the risk of type 2 diabetes, elevated blood glucose in the NDH range is associated with early changes to blood vessels and nerves, even before a formal diabetes diagnosis is made. This means that some of the long-term complications associated with diabetes, including an increased risk of heart attack, stroke, and kidney disease, may begin to develop during this stage if blood glucose remains persistently elevated.

There is also evidence that people with NDH are at greater risk of developing non-alcoholic fatty liver disease and other cardiovascular risk factors, including hypertension and dyslipidaemia.^[15] These risks are compounded by obesity, physical inactivity, and a diet high in refined carbohydrates and saturated fat. For this reason, comprehensive cardiovascular risk management is an important part of care for people with NDH: this includes assessment of blood pressure, lipid levels, and smoking status, and may involve a formal cardiovascular risk assessment such as QRISK, in line with NICE guidance on lipid modification for primary prevention.

The encouraging finding from the Diabetes Prevention Program trial is that modest weight loss of around 5% to 7% of body weight, combined with regular moderate physical activity, reduced the risk of progression to type 2 diabetes by approximately 58% in that study population.^[4][5] Early identification and action are therefore central to reducing the long-term burden of NDH.

What blood sugar levels should you aim for with prediabetes?

The aim is to reduce HbA1c below 42 mmol/mol and fasting plasma glucose below 5.5 mmol/l through lifestyle change, with annual monitoring recommended to track progress and detect any progression towards type 2 diabetes.

The overall aim for someone with non-diabetic hyperglycaemia is to reduce HbA1c and fasting plasma glucose towards the normal range as part of broader risk reduction, rather than to meet a set of strict glycaemic targets. NICE guidance (PH38) frames management around lifestyle change and risk reduction. As a general guide, an HbA1c below 42 mmol/mol (6.0%) and a fasting plasma glucose below 5.5 mmol/l are within the normal range, and moving towards these levels is associated with a substantially reduced risk of progression. Your GP will interpret your results in the context of your overall health, weight, age, and other risk factors, and will discuss what is realistic and appropriate for you individually.

NICE PH38 recommends that people identified with an HbA1c in the NDH range (42 to 47 mmol/mol) are monitored annually to track whether levels are improving, stable, or progressing towards the diagnostic threshold for type 2 diabetes (48 mmol/mol or above on a repeat test).^[1][2] If your HbA1c rises to 48 mmol/mol or above, a confirmatory test is usually required before a diagnosis of type 2 diabetes is made, unless you have clear symptoms, in line with NHS and NICE diagnostic criteria. Your GP will discuss the next steps in management at that point.

Achieving meaningful risk reduction typically involves a combination of the following:

• Dietary changes: reducing intake of refined carbohydrates, sugary drinks, and processed foods, while increasing fibre, vegetables, and lean protein.

• Physical activity: the UK Chief Medical Officers' Physical Activity Guidelines recommend at least 150 minutes of moderate-intensity activity per week for adults, alongside muscle-strengthening activities on two or more days per week.^[13][14] Regular activity has a direct beneficial effect on insulin sensitivity.

• Weight management: even modest weight loss can produce meaningful improvements in HbA1c and fasting glucose, as demonstrated in the Diabetes Prevention Program trial.

• Regular monitoring: annual HbA1c checks allow your GP to assess whether your levels are moving in the right direction and to adjust your care plan accordingly.

Attending all follow-up appointments is important for catching any progression early. If you develop symptoms such as increased thirst, frequent urination, or unexplained weight loss between appointments, contact your GP promptly rather than waiting for your next scheduled review.

Scientific References

1. Type 2 diabetes: prevention in people at high risk (PH38).
2. Type 2 diabetes: prevention in people at high risk (PH38) – Recommendations.
3. Diabetes: NDH annual HbA1c or FPG test (IND172).
4. Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin (Knowler et al.).
5. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin (Knowler et al.) – PubMed.
6. Metformin hydrochloride | Drugs – BNF – NICE.
7. Semaglutide | Drugs – BNF – NICE.
8. GLP-1 medicines for weight loss and diabetes: what you need to know.
9. Semaglutide (Wegovy, Ozempic, Rybelsus) – NHS Medicines.
10. Semaglutide for managing overweight and obesity (TA875).
11. Tirzepatide for managing overweight and obesity (TA1026).
12. MHRA authorises Mounjaro (tirzepatide) for weight management and weight loss.
13. UK Chief Medical Officers' physical activity guidelines.
14. Physical activity guidelines for adults aged 19 to 64.
15. Increased fetuin-A concentrations in impaired glucose tolerance with or without nonalcoholic fatty liver disease, but not impaired fasting glucose (J Clin Endocrinol Metab).

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