About the test
Glycated hemoglobin (or HBA1c) reflects the average blood glucose level over the preceding three months. (The three month period corresponds to the mean life time of red blood cells).
Blood glucose is bound to hemoglobin in three forms (HbΑ1a, HbΑ1b and HbA1c). HbA1c is the biggest of the three glycated fractions of hemoglobin and it is the one which is being measured in diabetes mellitus screening.
Sample
Venous blood
Preparation
None required. Sampling may take place any time during the day.
Procedure
Venipuncture
Increased values
- Diabetes mellitus
- Polycystic ovary syndrome
- Obesity
- Smoking
- Chronic use of opioids
- Drugs (aspirin, hydroxyurea)
Decreased values
- Hemolytic anemia
- Sickle cell anemia
- Chronic renal failure
- Splenectomy
Additional information
Falsely elevated values of HbA1c may be noticed in cases of iron deficiency anemia, after hemodialysis as well as after blood transfusion.