Glucose tolerance test at OpenMed Warsaw
See also: Laboratory tests, Collection point, Diabetology, Endocrinology.
The glucose tolerance test, also known as the oral glucose tolerance test (OGTT) or glucose curve, is a laboratory examination used to assess how the body metabolises sugar. It is one of the key diagnostic tools for detecting diabetes, pre-diabetes and gestational diabetes. At OpenMed in Warszawa, we perform the OGTT with full patient support - from preparation instructions through to discussion of results and, if needed, a further treatment plan.
The test measures how blood glucose levels change after ingestion of a standardised glucose solution. By comparing fasting values with those obtained at set time intervals, the doctor can determine whether the body is processing sugar correctly or whether there are signs of impaired glucose metabolism.
When is a glucose tolerance test performed?
The OGTT is recommended in a number of clinical situations. Our doctors at OpenMed most commonly order it in the following cases:
- Gestational diabetes screening - every pregnant woman should undergo the test between weeks 24 and 28 of pregnancy, in accordance with current guidelines.
- Elevated fasting glucose - when fasting blood glucose falls within the range of 100-125 mg/dL, the OGTT helps to clarify whether pre-diabetes or diabetes is present.
- Risk factor assessment - for individuals with a family history of diabetes, excess body weight, polycystic ovary syndrome (PCOS) or a history of gestational diabetes.
- Monitoring of known pre-diabetes - to track disease progression and assess the effectiveness of lifestyle modifications.
The test is also used in endocrinological diagnostics, for example when investigating insulin resistance or reactive hypoglycaemia.
How is the glucose tolerance test performed at OpenMed?
The test follows a standardised protocol and takes approximately two hours. Here is what to expect:
- Fasting blood draw - you arrive at the collection point in the morning on an empty stomach (after at least 8 hours of fasting). A blood sample is taken to measure your baseline glucose level.
- Glucose solution - you drink a solution containing 75 grams of glucose dissolved in water. The solution has a sweet taste and should be consumed within five minutes.
- Timed blood draws - blood samples are taken at 60 minutes and 120 minutes after drinking the glucose solution. In some cases, the doctor may request an additional measurement at 30 or 180 minutes.
Throughout the test, you remain at the clinic and should avoid eating, drinking (other than water) and physical exertion. Our staff ensure a comfortable waiting environment and are available to answer any questions.
How to prepare for the glucose tolerance test
Proper preparation is essential for reliable results. We recommend the following:
- Do not fast for more than 14 hours before the test - an overnight fast of 8 to 12 hours is sufficient.
- Maintain your normal diet for at least three days before the test - do not restrict carbohydrates, as this may affect the results.
- Avoid intense physical activity on the day before and the day of the test.
- Inform the doctor about any medications you are taking, as some can influence glucose metabolism.
- Arrive well-rested - stress and sleep deprivation can affect blood sugar levels.
Detailed preparation instructions are provided by our staff during registration.
Interpreting the results
The results of the OGTT are assessed based on established diagnostic criteria:
- Normal result - fasting glucose below 100 mg/dL and two-hour glucose below 140 mg/dL.
- Pre-diabetes (impaired glucose tolerance) - two-hour glucose between 140 and 199 mg/dL.
- Diabetes - two-hour glucose of 200 mg/dL or above.
For gestational diabetes screening, slightly different thresholds apply and the results are interpreted according to specific obstetric guidelines.
After receiving your results, a doctor at OpenMed will discuss them with you, explain what they mean and recommend the next steps - whether that involves lifestyle modifications, further testing or specialist consultation.
Book a glucose tolerance test at OpenMed Warsaw
If you need a glucose tolerance test in Warszawa, book at OpenMed. Registration is available by phone and online. Our team will help you choose a convenient morning appointment and provide all the necessary preparation details.
FAQ - Glucose tolerance test
Do I need to fast before the glucose tolerance test?
Yes, fasting for at least 8 hours before the test is required. You may drink water. Arrive in the morning without having eaten breakfast.
How long does the glucose tolerance test take?
The entire test takes approximately two hours from the first blood draw. You should plan to stay at the clinic for the full duration.
Is the glucose tolerance test painful?
The test involves standard blood draws, which cause only brief, minor discomfort. The glucose solution has a very sweet taste, which some patients may find unpleasant.
Can I have the OGTT during pregnancy?
Yes, the glucose tolerance test is a standard part of prenatal care and is recommended for all pregnant women between weeks 24 and 28. It is safe for both mother and baby.
What should I do if my result is abnormal?
An abnormal result does not necessarily mean you have diabetes. Your doctor will discuss the findings with you and may recommend further tests, lifestyle changes or referral to a diabetologist for specialist management.