8 Differences between Prediabetes and Diabetes (2024)

According to research published in Diabetes Journal, around 5.8% of the world's population have prediabetes as of 2021. 

However, prediabetes doesn’t usually present with symptoms; many go undiagnosed for a long time.

It’s worth noting that the blood sugar levels in prediabetes remain below the threshold needed to diagnose diabetes. Nevertheless, if left unattended, the risk of progressing to full-blown diabetes is very high.

This article will explore some of the main differences between prediabetes and diabetes. Such distinctions can give you more insight into when to seek a healthcare professional, efficiently control high blood sugar levels, and minimize diabetes risk.

While both conditions affect blood sugar levels, some key distinctions exist.

As its name implies, prediabetes refers to the condition that could precede diabetes. Here, the blood glucose levels are higher than normal but still not high enough to get a diabetes diagnosis.

Prediabetes carries an increased risk for several other health problems like heart disease, strokes, and high blood pressure.

The main risk factors for prediabetes include:

• A sedentary lifestyle: being physically inactive

• Obesity / being overweight.

• Smoking

• High and frequent alcohol use, etc.

• High blood pressure.

• Age: risk increases as we age .

• Family history (genetics).

• Ethnic background.

The good news is that prediabetes can be reversible with a healthy diet, regular exercise, and weight loss.

The takeaway message here is that early detection of prediabetes is key to avoiding the more serious health consequences that come with uncontrolled blood sugar levels.

This is the most common form of the condition. Old age, obesity, and a sedentary lifestyle are risk factors for developing type 2 diabetes.

The main mechanism behind the disease is insulin resistance. The body's cells are unable to use insulin efficiently. This translates into higher blood sugar levels, as the cells can’t take in circulating glucose and break it down for energy production.

Type 1 diabetes is considered less common as it only accounts for 5 to 10% of all cases. It’s related to impairment in the normal pancreatic ability to produce insulin. 

Genetic and environmental factors contribute to the development of type 1 diabetes.

This type of diabetes exclusively develops during pregnancy. Following delivery, the blood sugar levels normalize, and the mother’s metabolic functions return to normal.

However, mothers who've dealt with gestational diabetes have an increased risk of developing type 2 diabetes down the line. They need regular blood tests to help detect early fluctuations in blood glucose levels and provide timely diabetes care.

Now that there’s a clear line drawn between prediabetes and diabetes, let’s get into the nitty and gritty details and look into how the two conditions differ:

The CDC reports 37.3 million Americans had diabetes in 2019, while around 96 million had prediabetes. Roughly 8.5 million of them are yet to be diagnosed, emphasizing how much more resources can be allocated to early detection and screening.

In the UK, NHS England (2023) reported there are currently two million people in England at high risk of developing type 2 diabetes

We see the same trends on a global scale. There’s a discrepancy between the actual number of people with impaired fasting blood glucose levels and those diagnosed with prediabetes. The estimated global population with prediabetes is predicted to rise from 5.8% in 2021 to 6.5% in 2045.

It’s not surprising to see many prevention programs dedicated to limiting the disease's progress before it reaches the irreversible point of no return. You can read more prediabetes and diabetes-related statistics by visiting the American Diabetes Association and NHS England websites: NHS Diabetes Prevention Programme.

The US based National Diabetes Prevention Program has set different diagnostic criteria for narrowing down on a prediabetes or diabetes diagnosis. Bear in mind that the test of choice must be repeated twice before making a definitive diagnosis. 

In the UK, The Healthier You NHS Diabetes Prevention Programme (NDPP) supports  services in England for people with non-diabetic hyperglycaemia or women with a previous history of gestational diabetes and normoglycaemia, who are at high risk of developing Type 2 diabetes.

• Fasting plasma glucose: Such a blood test requires fasting for at least 8 hours or overnight. A blood sample is then taken, and prediabetes is highly likely if the blood sugar levels are between 100 and 125 mg/dl.

• Oral glucose tolerance test: Just like the fasting plasma glucose test, you must fast for 8 hours before taking the test. A baseline blood glucose level is recorded, and then you’ll be asked to consume sugary beverages with a meticulously calculated glucose concentration. Two hours later, the blood sugar levels are measured again, and prediabetes is diagnosed when the test values are between 140 to 199 mg/dl. (In the UK this is rarely used clinically for diagnosis of hyperglycaemia outside pregnancy)

• Hemoglobin A1C (HbA1C) : This test measures the percentage of glycated hemoglobin. In other, this looks into the percentage of glucose linked to hemoglobin by an irreversible, non-enzymatic reaction. Such a test shows the blood sugar levels for the past 2 or 3 months. For a prediabetes diagnosis, you need HbA1C levels to fall between 5.7% to 6.4%.

• Fasting plasma glucose: According to the American Diabetes Association, diabetes is diagnosed when the fasting glucose levels are higher than 126 mg/dl on two different occasions. In the UK a fasting plasma glucose concentration ≥ 7.0 mmol/l (whole blood ≥ 6.1 mmol/l) may indicate diabetes, although more than 1 test will be used to confirm diabetes.

• Oral glucose tolerance test: Two hours after consuming a sugary solution, the blood sugar levels need to be higher than 200 mg/dl for an impaired glucose tolerance test. ( In UK a, two-hour plasma glucose concentration ≥ 11.1 mmol/l two hours after 75g anhydrous glucose in an oral glucose tolerance test) Again, the test has to be repeated on another occasion before a final diagnosis of diabetes is made.

• HbA1C: As you’d expect, the hemoglobin A1C levels to diagnose diabetes are higher than those we’ve previously seen with prediabetes. Here, hemoglobin A1C is higher than or equal to 6.5%.

For the most part, prediabetes is a silent condition lacking noticeable symptoms. This requires a higher attention to warning signs to seek medical attention and get more tests before the condition worsens. People with prediabetes can report mild changes in the frequency of urination, unexplained fatigue, and increased thirst.

On the other hand, as long as diabetes is controlled, the condition doesn’t cause any distressing symptoms. However, high blood glucose levels are detrimental to a variety of organ systems, and those are responsible for the classical diabetes presentation.

Diabetics usually have the following symptoms:

• Significantly increased urination that could wake the patient while sleeping.

• Increased thirst to replace the fluid loss through urination.

• Unexplained weight loss due to the body’s inability to utilize circulating blood sugar. This leads to the consumption of the body's stores of glycogen and fat.

• Impaired blood circulation due to high blood glucose injures the blood vessels. This explains why people with diabetes have an impaired ability to heal wounds.

• Increased susceptibility to infections due to poor wound healing and the availability of higher levels of sugar upon which bacteria thrives.

Taking care of the two conditions also requires different approaches.

The scientific community is always looking for evidence-based approaches to prevent the progression of prediabetes to diabetes.

An oral glucose-lowering drug like metformin can be used to treat diabetes. Other medications are also available.

Lifestyle interventions like eating healthy foods, losing excess weight, and remaining physically active can help reduce the risk factors for prediabetes progression.

Limiting alcohol and tobacco consumption can do wonders for your overall health.

Although people with diabetes can benefit from the same management strategies, the treatment plans involve more essential pillars. Oral glucose-lowering drugs are effective in type 2 diabetes as they improve insulin sensitivity and allow the body cells to make the most of the circulating hormone levels no matter how low they can be.

Since a type 1 diabetes patient's pancreas cannot produce insulin, they need insulin therapy.

For the best glycemic control, insulin injections should stimulate the body’s normal hormone secretion patterns. Rapid-acting formulations should be taken before meals so the insulin spike coincides with when simple carbohydrates are absorbed and cause the blood sugar levels to rise.

Discussing the different management plans is the perfect segue for how prediabetes and diabetes compare regarding reversibility. With consistent lifestyle changes, prediabetes is reversible, and impaired fasting glucose levels can normalize.

In contrast, the underlying mechanism for diabetes is usually irreversible. The increased insulin resistance puts extra stress on the pancreatic insulin-producing cells. At some point, such cells will be exhausted and unable to produce insulin anymore. Proper disease control delays such an endpoint and minimizes the risks of developing diabetes-related complications.

Since prediabetes and diabetes are on the same disease spectrum, the risk factors of both conditions are more or less the same. The main difference is related to the severity of exposure and the number of risk factors the individual is exposed to simultaneously.

Here are some of the factors that increase the likelihood of prediabetes and diabetes:

• Being over the age of 45

• Having a family history of type 2 diabetes

• Lack of physical activity

• A higher percentage of visceral fat

• Not following healthy eating habits

• Having certain diseases like polycystic ovary syndrome

Regular check-ups with your healthcare practitioner are recommended to ensure effective monitoring and management of your diabetes. Such visits should involve taking blood samples and testing for blood sugar levels, foot checks, weight checks and lifestyle reviews.

This can be complemented by regular blood tests at home and seeking immediate medical care upon noticing serious fluctuations from the baseline.

On the other hand, patients with diabetes require more frequent testing, especially if they have suboptimal disease control.

Based on the results, oral glucose-lowering drugs and insulin dosage can be tweaked to achieve the best care.

Prediabetes shouldn’t pose any serious life issues, especially if the condition is controlled and it doesn’t progress into diabetes.

The same can’t be said about diabetes, as the metabolic disorder has potential negative outcomes on overall health and quality of life.

Here are some of the complications associated with diabetes:

• Increased risk of heart disease, including heart attacks and strokes.

• Kidney disease with progressive loss of function that might require dialysis or transportation in severe cases.

• Over time, high blood glucose levels can cause nerve damage, which starts as tingling or numbness in the hands and feet. The condition can progress to complete loss of sensation, increasing susceptibility to foot injuries.

• Higher blood sugar levels can damage the retina's blood vessels, the light-sensitive nerve layer of the eyes. This can lead to blurry vision, frequent changes in your prescription lenses, and in the most severe cases, can lead to blindness.

By now, you should appreciate the serious efforts dedicated to diagnosing prediabetes in its early stages and preventing the disease progression to diabetes. High-risk groups and people with prediabetes should be extra vigilant in monitoring for high blood sugar.

In addition to having regular checkups and consulting your healthcare provider, you can adopt a series of positive lifestyle interventions to avoid developing diabetes. Maintaining a healthy weight, being physically active, and adopting healthy eating patterns can help minimize the risk of developing diabetes.