Diabetes Screening (HbA1C & Fasting Sugar)

The FBS (Fasting Blood Sugar) test measures the glucose level in the body under overnight fasting conditions. Glucose is the body's energy currency and is broken down through metabolism to produce energy. Hormones and enzymes produced by the liver and pancreas control this process. The hormone insulin, produced by the pancreas, regulates blood glucose levels. When these levels are high, such as after a meal, insulin is secreted to transport glucose into cells for energy production. Elevated glucose levels in the body after fasting may indicate a risk of developing prediabetes or diabetes, which can be of two types: Type 1, caused by little or no insulin production, and Type 2, caused by insulin resistance or decreased insulin production.

The HbA1c (Glycosylated Hemoglobin) test precisely measures the percentage of sugar-coated or glycated hemoglobin in your blood. The test results represent the proportion of hemoglobin in your blood that has been glycated. 

Hemoglobin, a vital protein found in red blood cells, is responsible for transporting oxygen throughout the body. Hemoglobin A is the most abundant form of hemoglobin, and when blood sugar levels increase, a higher proportion of hemoglobin A becomes glycated. As red blood cells have a lifespan of approximately 120 days, the sugar molecules remain attached to the hemoglobin for the duration of the cell's life. Consequently, the HbA1c (Glycosylated Hemoglobin) test offers insight into your average blood sugar levels over the past 8 to 12 weeks.

What Do the Results Mean?

Pathological Factors

Key: ⇧: Indicates High Levels , ⇩: Indicates Low Levels

Physiological Factors

 🧒Age: HbA1c tends to increase slightly with age, even in non-diabetics.

🫄Pregnancy: HbA1c levels typically decrease due to increased red blood cell turnover, especially in the second and third trimesters.

Lifestyle Factors

 🥗Diet: Consistently high sugar intake leads to elevated HbA1c over time.

😟Stress: Chronic stress can affect blood glucose levels and thus HbA1c.

😴Sleep: Poor sleep quality and sleep disorders may worsen glucose control and raise HbA1c.

🚬Smoking: Smoking can increase insulin resistance and raise HbA1c levels.

🍷Alcohol: Excessive alcohol use can cause fluctuations in blood sugar and affect HbA1c accuracy.

Disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment. Always consult your healthcare provider for personalized guidance.

What Do Normal HbA1c Levels Mean?

A normal HbA1c level is generally below 5.7%. This indicates that your blood sugar has been well controlled over the past 2–3 months. Staying in this range suggests your body is managing glucose effectively and helps reduce the risk of future health problems.

What High HbA1c Levels Indicate?

An HbA1c level between 5.7% and 6.4% usually suggests prediabetes, where blood sugar is higher than normal but not yet in the diabetic range. A level of 6.5% or above typically indicates diabetes. 

What to Do if Your HbA1c Is Higher Than Normal?

If your HbA1c level is above the recommended range, try not to panic. Many people are able to bring it down with the right lifestyle changes, such as healthier eating, regular physical activity, and proper medication when needed. It is important to consult your doctor, who can guide you on the best steps for managing and improving your HbA1c.

What Do Low Levels of HbA1c Indicate?

Low HbA1c level (below 4%) is uncommon and may point to issues such as excess insulin use, anemia, or other conditions that shorten the lifespan of red blood cells. Since low readings can have different underlying causes, always consult a doctor to understand what they mean in your specific case.

Can HbA1c Results Be Inaccurate?

Yes. Certain conditions such as recent blood transfusion, pregnancy, liver or kidney disorders etc., can affect the test accuracy. If your results do not match your symptoms or overall health, your doctor may suggest repeating the test or additional testing. In hemoglobinopathies, where the normal form of hemoglobin (HbA1) is reduced or absent, HbA1c values may be inaccurate or may not be reported at all. In such cases, results should be interpreted along with other tests like fasting blood sugar, post-prandial blood sugar, or the Fructosamine test.

What Factors Can Affect HbA1c Results?

Though it is a reliable test, several factors can influence accuracy:

• Blood disorders such as anemia, sickle cell trait, or chronic blood loss
• Recent blood transfusion 
• Kidney or liver diseases
• High-dose vitamin supplementation (such as vitamin C or E)
• Certain medications, including those for HIV or anemia
• Pregnancy (second and third trimester)
• Ethnic differences in hemoglobin structure (hemoglobinopathies)

What Follow-Up Tests May Be Required?

Based on your HbA1c results, your doctor may recommend additional tests to get a clearer picture of your health or to monitor possible complications. These may include: 

How Does HbA1c Differ from Other Blood Glucose Tests?

It is important to understand how the HbA1c (Glycosylated Hemoglobin) test differs from other common blood sugar tests: 

Fasting Blood Glucose (FBS): Measures blood sugar at a single point in time, usually after 8–12 hours of fasting.

Random Blood Glucose (RBS): Measures blood sugar at any time of the day, regardless of meals, giving a quick snapshot of current levels.

Oral Glucose Tolerance Test (OGTT): Measures how the body processes sugar by checking blood glucose before and after drinking a glucose solution.

Postprandial Blood Sugar Test (PPBS): Measures blood sugar levels after a meal (usually 2 hours post eating) to assess how well the body manages glucose following food intake.