Prediabetes: definition, causes and treatment

June 15, 2022
6 minute read

Type 2 diabetes is a common chronic condition which causes the levels of sugar in the blood to become too high. In the UK, roughly 4.7 million people are diagnosed with diabetes, of which 90% suffer from type 2 diabetes. It is projected that by 2025, more than 5 million people will have diabetes in the UK.

A further one million people are currently thought to be living with undiagnosed type 2 diabetes.

Sometimes referred to as “borderline diabetes”, prediabetes occurs when blood sugar levels are higher than normal, but not high enough to be diagnosed as type 2 diabetes. Prediabetes is an indicator of a significantly higher risk of developing type 2 diabetes in the future.

How is prediabetes diagnosed?

Prediabetes is generally diagnosed with the help of blood tests, though the definitions of what constitutes prediabetes can sometimes vary and are not uniform across the board.

The World Health Organisation defines two specific parameters for diagnosing prediabetes: impaired fasting glucose and impaired glucose tolerance.

Impaired fasting glucose is defined as fasting plasma glucose between 110 to 125 mg/dL, while impaired glucose tolerance is defined as plasma glucose levels between 140-200 mg/dL two hours after ingesting 75g of oral glucose.

In the UK, prediabetes is commonly diagnosed using a test called the HbA1c test, which looks at your average blood glucose levels over the past few months.

If your HbA1c level is between 6% and 6.4%, this means your blood sugar levels are higher than normal, and you are then classified as prediabetic, which put you at higher risk of developing diabetes.

Causes of prediabetes

As prediabetes is a condition that develops before diabetes, the causes of prediabetes are the same as the causes of type 2 diabetes. As such, it’s important to be aware of the main type 2 diabetes risk factors.

You will be more at risk of developing type 2 diabetes:

  • If you are overweight or obese, and especially if you carry a significant amount of weight around the waist area
  • If you suffer from high blood pressure
  • If there’s a history of type 2 diabetes in your immediate family, such as parents, siblings and even children
  • If you’re over the age of 40 and white, or if you’re over the age of 25 and you are Black African, South Asian or African-Caribbean

You can use the Know Your Risk Online Tool in just a few minutes to assess whether you are at risk of diabetes.

Symptoms and signs of prediabetes

Prediabetes doesn’t have any symptoms, which is why it’s crucial to be familiar with the main risk factors that we outlined above. Seeing your GP for regular check-ups is crucial to identify prediabetes and diabetes early.

In many cases, even type 2 diabetes may present very few or hardly noticeable symptoms for many years.

If you start to notice any of the symptoms of type 2 diabetes (excessive thirst, frequent urination, tiredness, blurred vision, slow healing of wounds and cuts), that means you’ve already developed it.

Seeing your GP for regular check-ups is crucial to identify prediabetes and diabetes early.

Treating prediabetes and preventing type 2 diabetes

If you’ve been diagnosed with prediabetes, this doesn’t necessarily mean that you’ll develop type 2 diabetes. In fact, with the right lifestyle interventions, roughly 50% of prediabetics can either fully prevent or delay type 2 diabetes.

Treatment for prediabetes consists of:

  1. Weight loss and weight management
  2. Making appropriate, healthy changes to your diet
  3. Reducing sedentarism and increasing your levels of physical activity

1.     Weight loss for treating prediabetes

Losing weight is often the most important intervention in treating prediabetes and preventing type 2 diabetes. If you’ve been diagnosed with prediabetes, it’s generally recommended to lose at least 5% of your body weight, which can significantly reduce your risk of developing type 2 diabetes.

Losing weight can be challenging and requires making changes to your diet and lifestyle. It’s recommended that you speak to your GP, as they will be able to advise you on how to start losing weight and might even be able to recommend a dietitian or weight management service.

Weight loss can be achieved by maintaining a caloric deficit: this means taking in less energy than you expend. In practice, this means reducing the number of calories that you take in, while increasing the level of physical activity. This ties in to points two and three below.

2.     Eating a healthy and balanced diet

The term “healthy and balanced” can sometimes be rather vague in the context of nutrition and diet. In essence, there isn’t a single, universally healthy diet that is appropriate for everyone.

The changes that you make to your diet will depend on what food choices you currently make, and how much food you consume on a daily basis.

General guidelines are to consume a diet rich in fibre and healthy foods such as fruits, vegetables, lean protein and wholegrains.

Try to avoid:

  • Processed foods (such as pastries, white bread, fast food, sugary cereal, snacks and sweets)
  • Sugary drinks (sodas, sugary teas, sugary coffee)
  • Processed and red meats

Eat more of:

  • Fruits and vegetables (focus on green leafy vegetables and fruits such as berries)
  • Wholegrain foods
  • Healthy dairy products
  • Unsweetened drinks

Try to make small, gradual changes to your diet – this will increase the chances of succeeding over the long-term. Explore different foods and experiment with new healthy recipes to what you enjoy most.

3.     Becoming more active

Leading a sedentary lifestyle is a strong risk factor for a range of conditions and diseases, including prediabetes and type 2 diabetes.

Just as in the case of diet, it’s important to first assess your current habits and then start making small, gradual changes.

If you’ve determined that you lead a highly sedentary lifestyle (sitting for most of the day, little to no physical activity), start building healthier habits over time:

  • Take the stairs instead of the lift
  • Stand up and walk around when talking on the phone
  • Get off the bus a few stops earlier and walk the rest of the way home
  • Walk to the store rather than taking the car or public transport

Walking is a great way to increase your activity level.

Make sure to check in with your GP regularly, as they will be able to offer a proper diagnosis and recommend and individualised treatment plan.

If you need more information on prediabetes and type 2 diabetes, please visit the following pages:

Do you have any questions about prediabetes? Get in touch with our friendly pharmacy team who can help advise you.

Content last reviewed on:
June 15, 2022
Next review date:
June 15, 2024
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