What Is Prediabetes? Signs, Risks, and How to Prevent It Early

Prediabetes does not always cause symptoms, but it can be dangerous if left untreated.

We often feel tired easily, have trouble concentrating, or get thirsty quickly after being active. Many people assume these are signs of lack of sleep or ordinary fatigue. However, in fact, simple complaints like these may signal that the body is going through changes, including the possibility of blood sugar levels starting to rise.

In Indonesia, conditions like this are becoming more and more common. In fact, many adults, including people of working age, are starting to show early signs of prediabetes without realizing it. The complaints are often vague, so people carry on with their usual activities without knowing that their body is working harder than it should.

How Modern Lifestyles Have Changed Many Things

In our fast-paced daily lives, a high-sugar diet, long hours of sitting, prolonged stress, and little physical activity often become routines that are considered “normal.” But in reality, all of these slowly affect the way the body regulates blood sugar and energy.

This trend is not only seen in Indonesia. Health organizations such as the American Heart Association (AHA) and the Centers for Disease Control and Prevention (CDC) also report a growing number of cases of elevated blood sugar at younger ages as a result of modern lifestyle changes.

The Good News: This Condition Can Be Prevented Early!

Although it may seem worrying, the good news is that many studies show that early signs of blood sugar problems can be controlled, and even reversed. With early detection, consistent lifestyle changes, and the right health checks, a person can significantly lower the risk of the disease progressing, including the risk of heart problems.

That is why recognizing the condition early is an important step. The sooner a person understands their risk, the better their chances of keeping their heart and body healthy.

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What Is Prediabetes?

Prediabetes is a condition in which blood sugar levels are above normal but not yet in the type 2 diabetes category. This means the body is starting to show problems in regulating blood sugar, but the condition can still be controlled and reversed if it is addressed early.

To confirm a diagnosis of prediabetes, doctors use three blood sugar test parameters. These three tests look at blood sugar patterns from different angles, so the results are more comprehensive.

1. Fasting Plasma Glucose (FPG), or Fasting Blood Sugar

Diagnostic ranges:

• <100 mg/dL → Normal
• 100 to 125 mg/dL → Prediabetes
• ≥126 mg/dL → Diabetes

2. Oral Glucose Tolerance Test (OGTT), Measured at 2 Hours

This test looks at how the body responds to sugar after eating.

• <140 mg/dL → Normal
• 140 to 199 mg/dL → Prediabetes
• ≥200 mg/dL → Diabetes

3. HbA1c, Average Blood Sugar Over 3 Months

HbA1c gives a more stable picture of long-term blood sugar.

• <5.7% → Normal
• 5.7 to 6.4% → Prediabetes
• ≥6.5% → Diabetes

Prediabetes Can Still Be Reversed

In fact, prediabetes is not a permanent condition. Various large studies from the ADA, the CDC, and diabetes prevention programs show that:

• measured weight loss,
• regular physical activity,
• a balanced diet, and
• regular health checkups

can bring blood sugar levels back to the normal range. That is why early detection is the most important step in preventing type 2 diabetes.

Why Should Prediabetes Be Taken Seriously?

Prediabetes is not just a “mild warning”. This condition has long-term effects on metabolic and cardiovascular health. Various studies from the American Heart Association (AHA) and the European Society of Cardiology (ESC) show that elevated blood sugar can:

• speed up damage to the blood vessels (atherosclerosis),
• increase the risk of coronary heart disease,
• trigger stroke,
• and worsen obesity and metabolic syndrome.

PERKI (the Indonesian Heart Association) also emphasizes that metabolic disorders such as prediabetes play a major role in the rise of heart disease in Indonesia.

How Common Is Prediabetes in Indonesia?

According to Indonesia’s Basic Health Research (Riskesdas) 2018 by the Indonesian Ministry of Health, about 30% of Indonesian adults have fasting blood sugar levels above normal, a figure that places them in the prediabetes risk group.

This figure is likely to increase, especially in urban areas where lifestyles are more sedentary and sugar consumption is high.

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Prediabetes Symptoms That Often Go Unnoticed

Subtle Changes That Are Often Missed

One of the biggest challenges in recognizing prediabetes is that this condition often develops without symptoms. Many people still feel healthy even though their blood sugar levels are starting to rise.

Most cases of prediabetes are asymptomatic, so the signs are easily mistaken for ordinary fatigue or the effects of lifestyle.

However, understanding these small changes early is very important, because early symptoms can be a signal that the body is starting to lose its sensitivity to insulin.

Common Symptoms That May Appear

Although they are not always obvious, the following symptoms may appear when blood sugar levels are above normal.

1. Tiring Easily or Feeling Sluggish: When the body cannot use glucose optimally, energy runs out quickly. As a result, a person feels tired even after getting enough rest.
2. Frequent Thirst or Hunger: Rising blood sugar can disrupt fluid balance and cause more thirst or hunger than usual.
3. More Frequent Urination: The kidneys work harder to remove excess sugar. As a result, a person may urinate more often, especially at night.
4. Darkened Skin in Body Folds (Acanthosis Nigricans): Acanthosis nigricans often appears in prediabetes as a sign of insulin resistance. The most common areas are the neck, armpits, and body folds.
5. Weight Gain or Obesity: Excess body weight, especially around the abdomen, is a common sign of prediabetes. Central obesity is strongly linked to insulin resistance.

Warning Signs in Adults & Families

Besides symptoms, there are several risk signs that should not be ignored. These signs do not cause direct symptoms, but they increase alongside prediabetes.

1. Family History of Diabetes: Having a parent or sibling with diabetes increases the risk significantly.
2. Large Waist Circumference: A waist circumference of ≥90 cm (men) and ≥80 cm (women) is a strong indicator of insulin resistance.
3. Hypertension or High Cholesterol: Uncontrolled blood pressure and cholesterol often occur together with prediabetes and speed up blood vessel damage.
4. Inactive Lifestyle: Lack of physical activity is one of the main triggers of prediabetes. A sedentary lifestyle significantly increases the risk of insulin resistance.

Why Is It Important to Recognize Symptoms as Early as Possible?

Although most people with prediabetes do not have obvious symptoms, the signs and symptoms above can be the first signal that the body is experiencing impaired blood sugar regulation.

By recognizing these changes early, you can:

• prevent progression to type 2 diabetes,
• lower the risk of heart disease and stroke,
• and protect your long-term metabolic health.

Next, we will discuss the factors that cause this condition to develop.

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Causes and Risk Factors of Prediabetes

Prediabetes usually appears because the body starts to develop insulin resistance, a condition in which cells do not respond optimally to insulin, so blood sugar slowly rises. Insulin resistance is the main mechanism that pushes a person into the prediabetes phase.

In Indonesia, studies by the Indonesian Ministry of Health (Kemenkes) and various regional studies show that modern lifestyle changes, from lack of movement to high-calorie diets, are increasingly raising the risk of prediabetes among people of working age.

In addition, several biological factors and health history also increase a person’s susceptibility.

Main Risk Factors for Prediabetes

Here are the factors that have the greatest influence on the development of prediabetes.

1. Excess Body Weight (Overweight or Obesity): Excess body fat, especially belly fat, makes it increasingly hard for the body to use insulin. In fact, central obesity is one of the strongest risk factors linked to prediabetes.
2. Age 35 to 60: The risk of prediabetes does increase with age. However, many studies have found that people aged 30 to 40 are now more vulnerable because of sedentary lifestyles.
3. A Diet High in Sugar and Calories: Consuming sweetened drinks, ultra-processed foods, gorengan (deep-fried snacks), and oversized portions is a major trigger of insulin resistance. Riskesdas data from Kemenkes even show that people’s added sugar intake is still higher than the daily recommendation.
4. Lack of Physical Activity: A lack of physical activity means the body uses less energy, so insulin sensitivity decreases. Physical activity of <150 minutes per week significantly increases the risk of prediabetes.
5. Family History of Diabetes: If a parent or sibling has diabetes, the risk of prediabetes increases because of a combination of genetic factors and shared living habits.
6. History of Hypertension, High Cholesterol, or PCOS: Hypertension and dyslipidemia are part of metabolic syndrome, which is closely linked to prediabetes. In women, Polycystic Ovary Syndrome (PCOS) is an important trigger of insulin resistance from a young age.

Additional Risk Factors According to Studies in Indonesia

Besides the major factors above, several Indonesian studies have identified additional factors that also affect the risk of prediabetes.

1. Lack of Sleep: Sleeping <6 hours a night disrupts glucose metabolism and insulin sensitivity. Many national studies confirm a strong link between lack of sleep and increased blood sugar.
2. Chronic Stress: Long-lasting stress increases cortisol production, which then speeds up the rise in blood sugar.
3. History of Gestational Diabetes (During Pregnancy): Women who have had gestational diabetes have a higher risk of developing prediabetes or type 2 diabetes in the future.

Knowing the risk factors for prediabetes helps you recognize changes early and take preventive steps sooner. In fact, small changes such as increasing physical activity, improving your diet, or getting regular checkups can already have a big impact on your long-term health.

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Tests Used to Detect Prediabetes

Prediabetes often does not show clear symptoms. That is why laboratory tests are the recommended way to detect it early. First, a blood sugar test helps your doctor assess whether your blood sugar levels are already in the prediabetes range and determine the right preventive steps.

In addition, these tests are especially important if you have risk factors such as excess body weight, a high-sugar diet, or a family history of diabetes.

1. Laboratory Tests to Detect Prediabetes

Here are the three main tests doctors use to diagnose prediabetes accurately and consistently.

A. FPG (Fasting Plasma Glucose)

The FPG test is done after you have fasted for at least 8 hours.

Prediabetes range: 100 to 125 mg/dL

A result in this range indicates impaired blood sugar regulation, even though it is not yet in the diabetes category.

B. OGTT (Oral Glucose Tolerance Test)

The OGTT evaluates the body’s ability to process blood sugar after drinking a glucose solution. This test is more sensitive than the FPG, especially in patients with high risk factors.

Prediabetes range: 140 to 199 mg/dL (2 hours after consuming glucose)

This test is often recommended if FPG results are inconsistent or if a patient has features of prediabetes but previous test results were normal.

C. HbA1c (Hemoglobin A1c)

HbA1c gives a picture of the average blood sugar level over the past 2 to 3 months, so it is very helpful for assessing long-term blood sugar patterns.

Prediabetes range: 5.7 to 6.4%

The higher the HbA1c value within this range, the greater the risk of progressing to type 2 diabetes.

2. When Do You Need a Prediabetes Test?

Prediabetes testing is recommended not only for people with symptoms but also for those at high risk. The following conditions are strong indicators for getting tested:

• Having Mild Symptoms: Although they often go unnoticed, some early signals such as tiring easily, frequent thirst, urinating more often, or darkened skin (acanthosis nigricans) can indicate a blood sugar problem.
• Having Metabolic Risk Factors: The following conditions increase the likelihood of prediabetes:
  • excess body weight or a large waistline,
  • high blood pressure,
  • high cholesterol,
  • an inactive lifestyle,
  • a diet high in sugar and calories.
• Having a Family History of Diabetes: Family history is one of the strongest risk factors. If one of your parents or siblings has diabetes, your chance of developing prediabetes increases significantly.
• Women With a History of Gestational Diabetes (GDM): Women who have had GDM are at higher risk of prediabetes after giving birth. That is why regular checkups are strongly recommended.
• Age Over 35: Prediabetes testing should start at age ≥35, especially if combined with a less active lifestyle or a high-sugar diet.

Early Testing Reduces Long-Term Risk

Getting regular laboratory tests helps detect prediabetes earlier. In addition, the test results help your doctor determine the right management strategy, from lifestyle changes to medical intervention, so that the condition does not progress to type 2 diabetes.

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Can Prediabetes Go Away?

The answer: yes. Prediabetes is a reversible condition, which means blood sugar levels can return to the normal range if it is addressed early. In fact, research from the Centers for Disease Control and Prevention (CDC) shows that consistent lifestyle changes can prevent prediabetes from progressing to type 2 diabetes.

In addition, the Diabetes Prevention Program (DPP) by the National Institutes of Health showed that lifestyle intervention was more effective than medication in lowering the risk of diabetes. This finding offers great hope for anyone with prediabetes.

1. Losing 5 to 10% of Body Weight Makes a Big Difference

Weight loss does not have to be extreme. In fact, losing 5 to 10% of your starting weight has been shown to reduce the risk of diabetes by up to 58%, and by up to 71% in people over 60 (DPP Study).

Weight loss helps:

• improve insulin sensitivity,
• reduce inflammation,
• improve your lipid profile,
• lower the risk of heart disease.

2. Follow a Diet Low in Sugar & Refined Carbohydrates

Cutting back on refined carbohydrates and added sugar helps stabilize blood sugar.

Recommended eating pattern:

• choose complex carbohydrates (brown rice, oatmeal, quinoa),
• eat more vegetables and fiber,
• limit sweetened drinks,
• choose healthy fats,
• eat lean protein to stay full longer.

With these changes, blood sugar levels become more stable throughout the day.

3. 150 Minutes of Physical Activity per Week

Recommendation: 150 minutes of moderate-intensity exercise per week.

Examples of activities:

• brisk walking for 30 minutes/day,
• cycling,
• swimming,
• strength training 2 to 3 times/week.

Exercise helps the body use insulin more effectively and improves heart fitness.

4. Manage Stress to Keep Blood Sugar Balanced

Stress raises the hormone cortisol, which triggers a rise in blood sugar. Harvard Health names stress management as an important factor in preventing diabetes.

Simple ways to manage stress:

• breathing exercises,
• yoga,
• meditation,
• journaling,
• hobbies.

5. Get Enough Sleep

Lack of sleep is linked to insulin resistance and increased hunger (a study in the Annals of Internal Medicine).

Getting enough sleep helps:

• balance the hormones that control hunger and fullness,
• reduce stress,
• improve metabolism.

With focused lifestyle changes, from your diet to your sleep quality, prediabetes can be controlled and can even return to normal. Taking small steps today will have a big impact on your long-term health, including your heart health.

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How to Prevent Prediabetes From Progressing to Diabetes

Managing prediabetes early is very important to prevent it from progressing to type 2 diabetes. In fact, simple steps in your diet, physical activity, and daily habits can make a big difference in keeping blood sugar stable. In addition, the right lifestyle changes also help improve heart health, metabolism, and overall quality of life.

1. A Healthy Diet

Diet plays a major role in keeping blood sugar levels stable. Foods that are high in fiber and low on the glycemic index help improve insulin sensitivity. That is why a balanced diet is one of the important keys to preventing prediabetes from progressing to diabetes.

Eat more natural, high-fiber foods

Choose foods that help the body process sugar more steadily, such as:

• Non-starchy vegetables: broccoli, spinach, cauliflower, green beans.
• Low-glycemic-index fruits: apples, pears, oranges, berries.
• Lean protein sources: fish, eggs, skinless chicken, tofu, tempeh.
• Complex carbohydrates: oats, quinoa, whole wheat bread, brown rice.

Fiber slows down the absorption of glucose so that blood sugar does not spike suddenly.

Cut back on added sugar and processed foods

To keep blood sugar balanced:

• limit sweetened drinks,
• cut back on fast food, packaged food, and fried snacks,
• choose snacks based on fresh fruit or nuts without added sugar.

Sweetened drinks are one of the biggest contributors to rapid rises in blood sugar.

A simple daily menu example

• Breakfast: Oatmeal with apple & almonds.
• Lunch: Brown rice + grilled chicken + stir-fried vegetables.
• Snack: Unsweetened yogurt or berries.
• Dinner: Steamed fish + boiled vegetables + grilled tofu.

This menu is low on the glycemic index, high in nutrients, and helps you stay full longer.

2. Recommended Physical Activity

Physical activity is one of the recommended ways to prevent prediabetes from progressing to diabetes. Regular movement increases insulin sensitivity and helps the body use glucose for energy.

Brisk walking for 30 minutes a day

Minimum target:

• 150 minutes per week, or
• 30 minutes a day for five days.

Brisk walking is easy to do, needs no special equipment, and is safe for most people.

Strength training 2 to 3 times a week

Strength training builds muscle mass so that the body uses sugar more efficiently.

Example exercises:

• simple squats,
• wall push-ups,
• resistance bands,
• light weightlifting.

Everyday non-exercise activity

Besides formal exercise, small everyday movements also play an important role in preventing insulin resistance:

• sweeping or mopping,
• washing the dishes,
• gardening,
• taking the stairs.

These activities help burn glucose gradually throughout the day.

3. Daily Habits to Keep Blood Sugar Balanced

Besides diet and exercise, certain lifestyle habits play a major role in controlling blood sugar and preventing diabetes.

Drink enough water

Hydration helps the body regulate glucose concentration. Plain water is strongly recommended as your main drink because it contains no calories or sugar.

Limit sweetened drinks

According to the Harvard T.H. Chan School of Public Health, regularly consuming sugary drinks can increase the risk of diabetes by up to 26%.

Get enough sleep (7 to 9 hours a night)

Lack of sleep affects the hormones that regulate appetite as well as insulin sensitivity. Getting enough sleep helps keep your metabolism stable.

Manage stress

Chronic stress raises the hormone cortisol, which can push blood sugar up. Try:

• 5 minutes of deep breathing,
• gentle meditation,
• a relaxed walk,
• journaling,
• light stretching.

Emotional balance helps keep your daily metabolism stable.

Small Habits, Big Impact in Preventing Type 2 Diabetes

With a healthy diet, regular physical activity, enough sleep, and stress management, you can prevent prediabetes from progressing to diabetes. The good news is that these changes do not have to happen all at once. Start with small steps you can manage; the results can still be significant.

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Complications That Can Occur If Prediabetes Is Left Untreated

Prediabetes is a serious condition that needs attention from the start. If it is not treated, prediabetes can progress to type 2 diabetes and increase the risk of heart disease. Understanding these complications helps you take the right preventive steps before the condition gets worse.

1. Risk of Progressing to Type 2 Diabetes

Progression Risk to Watch For

According to the Centers for Disease Control and Prevention (CDC), 5 to 10% of people with prediabetes progress to type 2 diabetes every year. Over 5 years, the risk can even rise to 15 to 30%, especially if no lifestyle changes are made.

In fact, prediabetes is an “early warning” that the body is starting to struggle to manage blood sugar. If it is ignored, the chance of returning to normal levels becomes smaller and smaller.

Factors That Speed Up the Onset of Type 2 Diabetes

Several factors that significantly speed up the progression of prediabetes include:

• Excess body weight, especially fat buildup around the abdomen (visceral fat), which triggers insulin resistance
• Lack of physical activity, so the body does not use glucose optimally.
• A family history of diabetes, which increases genetic risk.
• Age 35 and older, especially in Asian populations, which are more susceptible.
• A history of gestational diabetes in women.
• Hypertension or high cholesterol, which are often linked to inflammation and metabolic disorders.

In other words, the more risk factors a person has, the faster prediabetes can turn into type 2 diabetes.

2. The Link Between Prediabetes and Heart Disease

The complications of prediabetes do not stop at diabetes. Prediabetes itself already increases the risk of cardiovascular disease, even before blood sugar reaches the diabetes threshold.

Chronic inflammation and insulin resistance

In prediabetes, the body develops insulin resistance, which is when the body’s cells do not respond effectively to insulin. This condition triggers:

• persistent mild inflammation (low-grade inflammation),
• impaired blood vessel function,
• increased oxidative stress.

Long-term inflammation can speed up blood vessel damage and trigger other metabolic disorders that are closely linked to heart disease.

Increased risk of atherosclerosis

Blood sugar levels in the prediabetes range can speed up the formation of atherosclerosis plaque, a buildup of fat, calcium, and cholesterol in the blood vessel walls.

As a result:

• blood vessels become stiff and narrow,
• blood flow to the heart decreases,
• the risk of heart attack and stroke increases.

Research in the Journal of the American College of Cardiology (JACC) also shows that people with prediabetes have a higher risk of coronary artery disease than those with normal blood sugar.

If prediabetes is left untreated, it is not only the risk of type 2 diabetes that rises; heart complications can also appear sooner. The good news is that early detection and lifestyle changes can significantly lower the risk.

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When Should You Consult a Doctor?

The sooner you get a medical evaluation, the better your chances of stabilizing your blood sugar and protecting your heart health.

Situations That Require a Medical Evaluation

If you experience any of the following conditions, you should consult a doctor as soon as possible. That way, prediabetes can be treated before it causes serious complications.

Prediabetes Symptoms Become More Frequent or More Noticeable

One sign that your body needs a checkup is symptoms that keep coming back, such as tiring quickly, frequent thirst, excessive hunger, or urinating more often. Small symptoms that keep recurring may point to a problem with blood sugar regulation.

Rapid or Uncontrolled Weight Gain

Sudden weight gain, especially around the abdomen, is a major trigger of insulin resistance. Visceral fat worsens metabolism and increases the risk of prediabetes progressing to diabetes.

A Family History of Type 2 Diabetes

If a parent or sibling has diabetes, your risk increases significantly. For this reason, regular checkups become much more important, even if you do not feel any symptoms.

Blood Sugar Test Results Show Abnormal Numbers

You should see a doctor if your test results fall within the prediabetes range, such as:

• FPG 100 to 125 mg/dL
• OGTT 140 to 199 mg/dL
• HbA1c 5.7 to 6.4%

In addition, blood sugar levels that have been unstable for several months should also be evaluated further by a doctor to determine the right preventive measures.

Regular Checkups as a Preventive Step

Rather than waiting for symptoms to appear, regular checkups are much more effective in preventing prediabetes from turning into type 2 diabetes. Regular screening helps detect metabolic changes earlier.

Why Are Regular Checkups Important?

1. They catch small changes before they develop into a serious condition.
2. They let you monitor how well lifestyle changes such as diet and exercise are working.
3. They help prevent heart complications, since prediabetes is often linked to cardiovascular risk.
4. They give you peace of mind because you clearly know your condition.

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Conclusion

Prediabetes is an early warning that you can control, not something to be afraid of. In fact, many studies, including those from the Centers for Disease Control and Prevention (CDC), show that prediabetes can return to normal if it is detected early and managed properly.

In addition, experts from PAPDI (the Indonesian Society of Internal Medicine) and various international health institutions also emphasize that preventive steps at the prediabetes stage are an important key to avoiding type 2 diabetes and other metabolic complications.

Early detection offers the greatest opportunity to stop or reverse prediabetes. The CDC even notes that healthy lifestyle changes can lower the risk of type 2 diabetes by up to 58%, and by as much as 71% in people over 60.

In addition, regular checkups help monitor changes that often go unnoticed, from rising blood sugar and body weight to blood pressure. In other words, prediabetes becomes easier for you to control when it is found earlier.

Regular Checkups + Healthy Lifestyle = Prevention Strategy

Not only checkups, but also a consistent lifestyle helps slow the progression of prediabetes. That is why combining these two steps, regular checkups and lifestyle changes, is a recommended strategy, both for prevention and for long-term monitoring.

If you have risk factors or are starting to worry about prediabetes, fasting blood sugar and HbA1c tests are also available in the Medical Check-Up (MCU) packages at Heartology Cardiovascular Hospital.