“Normal” Blood Sugar Levels May Still Mean You Have Prediabetes

FPG between 91 and 99 mg/dl is a strong independent predictor of type 2 diabetes, claims new study

Type 2 diabetes is a lifestyle disease in which the body no longer responds appropriately to the hormone insulin, which helps ferry sugar from the blood into our cells after a meal. When fasting blood sugar levels reach 126 mg/dl or more, doctors will diagnose diabetes

Prediabetes means that your blood sugar level is higher than normal, but it’s not yet increased enough to be classified as type 2 diabetes. Still, without intervention, prediabetes is likely to become type 2 diabetes in 10 years or less. (Scroll to end for Prediabetes FAQs)

Traditionally, blood sugar levels below 100 mg/dl have been considered “safe”, whereas levels between 100 and 126 signal a “higher risk” of diabetes (prediabetes). But according to the new study by Dr. Paolo Brambilla and colleagues at the University Milano Bicocca in Italy, the currently accepted “normal” blood sugar range might be too wide.

“FPG (Fasting Plasma Glucose) between 91 and 99 mg/dl is a strong independent predictor of type 2 diabetes and should be used to identify people to be further investigated and aided with preventive measures,” the researchers say. The conclusion significantly expands the “prediabetes” label.

To back their claim, the researchers report that in the course of their study they discovered people at the high end of what’s considered the “normal” blood sugar range are twice as likely to get the disease as are those in the low end. The findings are in line with an earlier study from Oregon, and the Italian researchers say they can help identify the people who need extra medical attention.

The researchers looked at data for nearly 14,000 men and women who’d had blood drawn several times at their clinic. The patients were between 40 and 69 years old and all of them had normal blood sugar levels at first. Over the next seven to eight years, on average, about two percent of the women and nearly three percent of the men developed diabetes.

Less than one percent of those who started out with fasting blood sugar levels between 51 and 82 mg/dl wound up with the disease, while more than three percent did so if they had values between 91 and 99. After controlling for other factors that might influence the likelihood of getting diabetes, that corresponded to a two-fold difference in risk of developing the disease.

Research has shown that if you have prediabetes, the long-term damage of diabetes — especially to your heart and circulatory system — may already be starting. If your blood sugar tests over 100 mg/dl fasting more than once, your fasting blood sugar is likely to go over the 125 mg/dl level used to diagnose full diabetes within 3 years.

More importantly, if your blood sugar is at 100 mg/dl fasting, it is very likely that your post-meal blood sugar is heading towards the diabetic range, which is over 200 mg/dl which is why your fasting blood sugar is deteriorating. High post-meal blood sugars kill beta cells. If you can bring down those post-meal highs, you may be able to prevent the beta cell death that is destroying your fasting control!

While opinion is divided on the question whether doctors should treat these people any different, as the researchers suggest, everyone agrees that people should strive to manage their weight and be physically active irrespective of what their blood sugar level is.

The bald reality is that, according to the American Diabetes Association, in the US alone there are three times as many prediabetics as people with diabetes (79:27 million). And It is estimated that there will be 418 million people worldwide with prediabetes by 2025.

How to Tell if You Have Prediabetes

The American Diabetes Association says while diabetes and prediabetes occur in people of all ages and races, some groups have a higher risk for developing the disease than others and warns that Diabetes is more common in African Americans, Latinos, Native Americans, and Asian Americans/Pacific Islanders, as well as the aged population. This means they are also at increased risk for developing prediabetes.

There are three different tests your doctor can use to determine whether you have prediabetes:

• The A1C test

• The fasting plasma glucose test (FPG)

• The oral glucose tolerance test (OGTT).

The blood glucose levels measured after these tests determine whether you have a normal metabolism, or whether you have prediabetes or diabetes.

If your blood glucose level is abnormal following the FPG, you have impaired fasting glucose (IFG); if your blood glucose level is abnormal following the OGTT, you have impaired glucose tolerance (IGT). Both are also known as prediabetes.

The American Diabetes Association Risk Test for Diabetes can help you determine if you are at increased risk for diabetes or prediabetes. A high score may indicate that you have prediabetes or at risk for prediabetes. Take the test and find out for sure.

ADA Prediabetes FAQs

What is prediabetes and how is it different from diabetes?

Prediabetes is the state that occurs when a person’s blood glucose levels are higher than normal but not high enough for a diagnosis of diabetes. About 11 percent of people with prediabetes in the Diabetes Prevention Program standard or control group developed type 2 diabetes each year during the average 3 years of follow-up. Other studies show that many people with prediabetes develop type 2 diabetes in 10 years.

What are the symptoms of prediabetes?

The reason why so many people suffer from prediabetes and are completely unaware of it is because it is quite possible for no symptoms to manifest themselves. Both diabetes and prediabetes develop at a gradual rate.

How do I know if I have prediabetes?

Doctors can use either the fasting plasma glucose test (FPG) or the oral glucose tolerance test (OGTT) to detect prediabetes. Both require a person to fast overnight. In the FPG test, a person’s blood glucose is measured first thing in the morning before eating. In the OGTT, a person’s blood glucose is checked after fasting and again 2 hours after drinking a glucose-rich drink.

How do I stop prediabetes developing into Type 2 diabetes?

The good news may be that, if you have become aware of the disease early, your condition can still be cured. The two principle factors for consideration are the changing of diet and the addition of appropriate physical exercise to your lifestyle. By making these changes, it may be possible to return blood sugar levels to normal. Prediabetes is a serious medical condition that can be treated.

The good news is that the recently completed Diabetes Prevention Program study conclusively showed that people with prediabetes can prevent the development of type 2 diabetes by making changes in their diet and increasing their level of physical activity. They may even be able to return their blood glucose levels to the normal range. But for a comprehensive and individual plan you should see your doctor.

Is prediabetes the same as Impaired Glucose Tolerance or Impaired Fasting Glucose?

Yes. Doctors sometimes refer to this state of elevated blood glucose levels as Impaired Glucose Tolerance or Impaired Fasting Glucose (IGT/IFG), depending on which test was used to detect it.

Why do we need to give it a new name? Has the condition changed?

The condition has not changed, but what we know about it has. We are giving IGT/IFG a new name for several reasons. prediabetes is a clearer way of explaining what it means to have higher than normal blood glucose levels. It means you are likely to develop diabetes and may already be experiencing the adverse health effects of this serious condition. People with prediabetes are at higher risk of cardiovascular disease. People with prediabetes have a 1.5-fold risk of cardiovascular disease compared to people with normal blood glucose. People with diabetes have a 2- to 4-fold increased risk of cardiovascular disease. We now know that people with prediabetes can delay or prevent the onset of type 2 diabetes through lifestyle changes.

How does the FPG test define diabetes and prediabetes?

Normal fasting blood glucose is below 100 mg/dl. A person with prediabetes has a fasting blood glucose level between 100 and 125 mg/dl. If the blood glucose level rises to 126 mg/dl or above, a person has diabetes.

How does the OGTT define diabetes and prediabetes?

In the OGTT, a person’s blood glucose is measured after a fast and 2 hours after drinking a glucose-rich beverage. Normal blood glucose is below 140 mg/dl 2 hours after the drink. In prediabetes, the 2-hour blood glucose is 140 to 199 mg/dl. If the 2-hour blood glucose rises to 200 mg/dl or above, a person has diabetes.

Which test is better?

According to the expert panel, either test is appropriate to identify prediabetes.

Why do I need to know if I have prediabetes?

If you have prediabetes, you can and should do something about it. Studies have shown that people with prediabetes can prevent or delay the development of type 2 diabetes by up to 58 percent through changes to their lifestyle that include modest weight loss and regular exercise. The expert panel recommends that people with prediabetes reduce their weight by 5-10 percent and participate in some type of modest physical activity for 30 minutes daily. For some people with prediabetes, intervening early can actually turn back the clock and return elevated blood glucose levels to the normal range.

What is the treatment for prediabetes?

Treatment consists of losing a modest amount of weight (5-10 percent of total body weight) through diet and moderate exercise, such as walking, 30 minutes a day, 5 days a week. Don’t worry if you can’t get to your ideal body weight. A loss of just 10 to 15 pounds can make a huge difference. If you have prediabetes, you are at a 50 percent increased risk for heart disease or stroke, so your doctor may wish to treat or counsel you about cardiovascular risk factors, such as tobacco use, high blood pressure, and high cholesterol.

Who should get tested for prediabetes?

If you are overweight and age 45 or older, you should be checked for prediabetes during your next routine medical office visit. If your weight is normal and you’re over age 45, you should ask your doctor during a routine office visit if testing is appropriate. For adults younger than 45 and overweight, your doctor may recommend testing if you have any other risk factors for diabetes or prediabetes. These include high blood pressure, low HDL cholesterol and high triglycerides, a family history of diabetes, a history of gestational diabetes or giving birth to a baby weighing more than 9 pounds, or belonging to an ethnic or minority group at high risk for diabetes.

How often should I be tested?

If your blood glucose levels are in the normal range, it is reasonable to be checked every 3 years. If you have prediabetes, you should be checked for type 2 diabetes every 1-2 years after your diagnosis.

Could I have prediabetes and not know it?

Absolutely. People with prediabetes don’t often have symptoms. In fact, millions of people have diabetes and don’t know it because symptoms develop so gradually, people often don’t recognize them. Some people have no symptoms at all. Symptoms of diabetes include unusual thirst, a frequent desire to urinate, blurred vision, or a feeling of being tired most of the time for no apparent reason.

Sources: American Diabetes Association, Diabetes Care, Diabetes UK