Prediabetes is a state in which blood sugar is higher than normal but has not yet reached the threshold for diabetes. It causes no symptoms, so it is almost always found on a routine blood test. It is an early warning sign: without change, a considerable share of people with prediabetes go on to develop type 2 diabetes within a few years, and with the right change the progression can be delayed and the values sometimes return to the normal range. It is worth seeing an endocrinologist when the values keep rising, when there are additional risk factors or when the question of medication comes up.
What the blood test results mean
Blood sugar is checked in three main ways, and each of them can point to prediabetes:
- Fasting glucose: a blood test after at least eight hours without food. A value between 100 and 125 milligrams per decilitre is considered prediabetes.
- Glycated hemoglobin, known as HbA1c: a test that reflects the average sugar level over the past three months and does not require fasting. A result between 5.7 and 6.4 is considered prediabetes.
- Glucose tolerance test: you drink a sugar solution and the blood level is checked after two hours. A value between 140 and 199 milligrams per decilitre is considered prediabetes.
A single abnormal result is not enough for a diagnosis. The doctor usually repeats the test or adds a test of another type, because a feverish illness, certain medicines and stress can raise sugar temporarily. Values above these ranges, on two separate tests, already fit a diagnosis of diabetes.
Why sugar rises
Insulin is a hormone released by the pancreas that allows sugar to move from the blood into the cells of the body. In most people with prediabetes the cells respond less well to insulin, a state called insulin resistance. The pancreas compensates by producing more, and for years the sugar level stays normal. When the pancreas can no longer keep up with the demand, sugar begins to rise, slightly at first and then more.
This process goes on for years, and during it a strain on the blood vessels is already building. That is why prediabetes is also linked to high blood pressure, high blood fats and fatty liver, and why the doctor looks at the whole picture and not only at the sugar value.
Who is at risk
The factors that raise the risk of prediabetes and type 2 diabetes are well known:
- Excess weight, mainly when fat accumulates around the abdomen.
- A first-degree relative with type 2 diabetes.
- Age forty-five and over, although the condition is now found in younger people as well.
- A sedentary lifestyle and little physical activity.
- Gestational diabetes in the past, or the birth of a particularly large baby.
- Polycystic ovary syndrome.
- High blood pressure, high triglycerides or low good cholesterol.
- Short or broken sleep over a long period, and sleep apnea.
Anyone with one or more of these factors should have fasting glucose or HbA1c checked as part of periodic tests, even when feeling well.
What really helps
Lifestyle change is the most effective treatment for prediabetes, and it has been studied thoroughly. There is no need for a revolution. Moderate changes that last have more effect than an extreme diet kept up for a month.
- Moderate weight loss: in people with excess weight, losing a few kilograms noticeably improves the response to insulin.
- Physical activity: about 150 minutes a week of brisk walking, swimming or cycling, spread over most days of the week. Strength exercises twice a week add to the benefit, because muscle is the main consumer of sugar.
- Less quickly absorbed sugar: cut down on sweetened drinks, juices, pastries and snacks. These raise sugar rapidly.
- More fibre: vegetables, legumes, whole grains and whole fruit in place of juice.
- Regular sleep: seven hours a night improve the response to insulin and reduce appetite.
- Stopping smoking, which in itself raises the risk of diabetes and heart disease.
It is worth setting one or two goals at a time and rechecking the values after three to six months. An improved result is a strong incentive to continue.
When medication is considered
Most people with prediabetes do not need medication. The doctor considers it when the values are close to the diabetes threshold or keep rising despite lifestyle change, when there is considerable excess weight, in women who have had gestational diabetes and in younger people with several risk factors together. The oldest and most thoroughly studied medicine in this situation improves the response to insulin, and it is given alongside lifestyle change and not in its place.
In recent years medicines for weight reduction have come into use, and they also affect sugar levels. Their suitability is assessed for each patient individually, according to the medical situation and the approved indications.
The link between prediabetes and the heart and blood vessels
Many people treat prediabetes as a matter of sugar alone, but the risk of heart and blood vessel disease is already raised at this stage. Insulin resistance usually appears together with high blood pressure, high triglycerides and fat accumulating in the liver, and all of these together put a load on the arteries. So the doctor does not settle for following the sugar. Blood pressure, blood fats and liver function are checked as well, along with questions about smoking and a family history of heart disease, and each factor is treated in its own right. Controlling blood pressure and blood fats matters just as much as lowering sugar, and the lifestyle changes described above improve all of them together.
When to see an endocrinologist
The family doctor follows most cases of prediabetes. A consultation with a private endocrinologist in Modi’in is particularly suitable in these situations:
- Values that keep rising despite a real effort to change.
- HbA1c approaching the diabetes threshold.
- Prediabetes at a young age or in a slim person, which raises questions about the type of diabetes.
- A combination of prediabetes with high blood pressure, high blood fats or fatty liver.
- Gestational diabetes in the past, or planning a pregnancy.
- A question about starting medication or treatment for weight reduction.
- Thyroid disease or long-term steroid treatment alongside the raised values.
At the visit the doctor goes over the tests, the family history and the medicines, measures blood pressure and waist circumference, and adds tests as needed: blood fats, liver and kidney function and thyroid function. The visit ends with a plan that has clear goals and a date for a repeat test.
When it is already urgent
Prediabetes itself is not an urgent condition. See a doctor promptly if you develop increased thirst, frequent urination, rapid and unexplained weight loss, blurred vision or extreme tiredness. These are signs that the sugar level is already high, and it should be checked without waiting for the periodic test.
At EliteMed in the Ayala 360 complex in Modi’in you can book an endocrinology consultation without a referral, and the visit can be held in English. Because prediabetes often appears together with high blood fats, it is also worth reading about high cholesterol and the cardiology work-up. The information here is general and does not replace an examination and advice from a doctor.
Frequently asked questions
Does prediabetes always turn into diabetes?
No. Prediabetes raises the risk, but the move to diabetes is not inevitable. Lifestyle change, mainly moderate weight loss and regular physical activity, delays the progression and in some people returns the values to the normal range. That is why it is important to act at this stage and not to wait.
How often should the tests be repeated?
It is accepted practice to check fasting glucose or HbA1c at least once a year. When the values are close to the diabetes threshold, or after a lifestyle change or the start of treatment, the doctor sometimes recommends a repeat test after three to six months to see the trend.
Do I need to give up carbohydrates completely?
No. The body needs carbohydrates, and the question is which type and how much. It is worth cutting down on quickly absorbed sugar such as sweetened drinks and pastries, and preferring whole grains, legumes and vegetables that raise sugar more slowly. A way of eating you can keep up for years is better than extreme avoidance.
Are there any symptoms of prediabetes?
Usually not, which is why it is found on blood tests. Sometimes dark, velvety patches appear in the skin folds of the neck or armpits, a sign of insulin resistance. Increased thirst, frequent urination and blurred vision usually indicate higher sugar values and need to be checked.
I am slim, so how can I have prediabetes?
Excess weight is a central risk factor but not the only one. Heredity, little movement, fat that accumulates around the internal organs, certain medicines and diseases of the pancreas can raise sugar in slim people too. In that situation it is worth consulting an endocrinologist, who will consider whether a further work-up is needed.