The gold standard for diagnosing diabetes

Based on your country's diabetes epidemiological survey data, the prevalence rate of diabetes among adults aged 18 and above stands notably high at 10.4%, underscoring the importance of accurate understanding and diagnosis of this condition. Despite the growing awareness, there remains confusion regarding the precise diagnostic methods and criteria for diabetes. The oral glucose tolerance test (OGTT), considered the gold standard for diagnosing diabetes, offers a standardized approach.

The OGTT procedure involves several steps to ensure accuracy and reliability:

1. Preparation: The individual must fast for at least 8 hours prior to the test, avoiding excessive eating the evening before to prevent skewed results. A fasting blood sample is taken in the morning, typically before 8 o'clock, to measure the fasting plasma glucose level.

2. Glucose Administration: Following the collection of the fasting sample, the patient consumes a solution containing 75 grams of anhydrous glucose dissolved in 300 milliliters of water. Timing begins from the first sip of the glucose solution, and additional venous blood samples are collected at 30, 60, 120, and 180 minutes after consumption.

3. Test Conditions: Throughout the OGTT, patients should refrain from consuming beverages like tea and coffee, smoking, or engaging in strenuous exercise, all of which could influence the glucose readings. However, absolute rest in bed isn't required.

4. Blood Glucose Testing: Venous plasma glucose concentrations are measured at each time point during the test. Simultaneously, checking the glycated hemoglobin (HbA1c) is recommended as it provides information about average blood glucose control over the previous few months.

5. Special Considerations: In cases where recent illness, injury, or stress-induced hyperglycemia may be present, it is advised to wait for a period of two weeks after recovery to conduct the OGTT for a valid assessment.

6. Medication Adjustment: Patients who are taking medications that can affect blood sugar levels should discontinue these drugs for at least one week before undergoing the OGTT to ensure an unaltered result.

In line with international standards set by the World Health Organization (WHO) in 1999, clinical diagnoses of diabetes are made based on venous plasma glucose levels determined through OGTT, along with other diagnostic criteria. These criteria help identify both fasting hyperglycemia and postprandial hyperglycemia, distinguishing between normal glucose tolerance, impaired glucose tolerance, and diabetes mellitus.