Lab Test #5: Understanding Fructosamine & HbA1c
Lab Test #5: Fructosamine and Glycated Hemoglobin (HbA1c)
1. Why is Fructosamine a Better Indicator Than Glycated Hemoglobin in Certain Cases?
Fructosamine is preferred over glycated hemoglobin (HbA1c) in situations involving:
- Rapid changes in diabetes treatment plans
- Diabetes during pregnancy (Gestational Diabetes)
- Loss or abnormalities of red blood cells (e.g., hemolytic anemia)
2. Substances that Interfere with Fructosamine Measurement
High levels of the following substances can interfere with fructosamine results:
- Vitamin C (ascorbic acid)
- Lipemia (elevated blood lipid levels)
- Hemolysis (red blood cell breakdown)
- Hyperthyroidism (overactive thyroid)
3. Normal Glucose Level
The normal range for glucose levels is 70 to 110 mg/dl.
4. Normal Glycated Hemoglobin (HbA1c) Level
The normal range for HbA1c is 4-6% of the total hemoglobin.
5. Method for Determining HbA1c
The process involves:
- Preparation of the hemolysate
- Preparation of glycated hemoglobin
- Measurement of total hemoglobin
- Calculation of results
6. Interpreting HbA1c Levels
Above Normal HbA1c:
A high HbA1c concentration indicates elevated blood glucose levels over the past 2-3 months, with the most recent two weeks having the strongest influence. This helps in assessing long-term glycemic control.
Below Normal HbA1c:
While lower HbA1c levels are generally desirable, excessively low levels may suggest frequent hypoglycemic episodes (low blood sugar). It’s important to note that HbA1c results may be unreliable in patients with hemoglobin variants.