Glycated hemoglobin is a form of hemoglobin that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously bond with hemoglobin, when present in the bloodstream of humans.
| Test Name | HbA1c; GLYCOSYLATED HEMOGLOBIN |
| Test Purpose | This assay is useful for diagnosing Diabetes and evaluating long term control of blood glucose concentrations in diabetic patients. It reflects the mean glucose concentration over the previous period of 8 to 12 weeks and is a better indicator of long term glycemic control as compared with blood glucose levels due to lesser day to day variation. |
| Pretest Preparations | No special preparation required |
| Category | Diabetes |
| Specimen | 3 mL (2 mL min.) whole blood in 1 Lavender Top (EDTA) tube. Ship refrigerated. DO NOT FREEZE. |
| Stability Room | 6 hrs |
| Stability Refrigerated | 1 week |
| Stability Frozen | NA |
| Method | High Performance Liquid Chromatography, NGSP certified |
Also Known as: A1c, HbA1c, Glycohemoglobin, Glycated Hemoglobin, Glycosylated Hemoglobin,Hemoglobin A1C, HgbA1c
Test Purpose:
- This test is used to monitor diabetes control.
- This test tells us the patient average glucose index over a long period of time (2 to 3 months).
- It tracks glucose in the milder form of diabetes.
- It helps to determine which type of drugs may be needed.
- Its measurement is of value in a specific group of patients like:
- Diabetic children
- Diabetic patients whose renal threshold for glucose is abnormal.
- Unstable diabetes type I, taking insulin.
- Type II diabetic women who become pregnant.
- Patients with changing dietary or other habits.
- It should be repeated every 3 to 4 months.
Sample Required:
- The blood sample is taken in the EDTA 3 to 4 ml.
- Washed RBC or hemolysate is prepared and this is stable for 4 to 7 days at 4 °C.
- A blood sample can be drawn at any time.
Normal
Source 1
- HbA1 c (% of total Hb) = 4.0 to 5.2
- Hb A1 (% of total Hb) = 5.0 to 7.5
Source 2
- Non Diabetic adult = 2.2 to 4.8 %.
- Non Diabetic child = 1.8 to 4.0 % .
- Prediabetic = 5.7 to 6.4 %
- Diabetics = >6.5 %
- Diabetic HbA1c = > 8.1 % = corresponds with glucose >200 mg/dl.
Diabetic Control And HbA1c
- Good diabetic control = 2.5 to 5.9 %.
- Fair diabetic control = 6 to 8 %.
- Poor diabetic control = > 8 %.
- (Values may vary according to the lab)
The following table gives a recommendation for the treatment:HbA1c level mg/dL mmol/L Interpretation 4 65 3.6 non-diabetic 5 100 5.55 non-diabetic 6 135 7.5 non-diabetic 7 170 9.5 ADA target 8 205 11.5 treatment needed 9 240 13.5 treatment needed 10 275 15.5 treatment needed 11 269 14.9 treatment needed 12 298 16.5 treatment needed 13 326 18.0 treatment needed 14 355 19.7 treatment needed
HbA1c And Estimated Blood Glucose Level:
| HbA1c level | Glucose level mg/dL |
| 4% | 65 |
| 5% | 100 |
| 6% | 126 |
| 7% | 154 |
| 8% | 185 |
| 9% | 212 |
| 10% | 240 |
| 11% | 270 |
| 12% | 300 |
| 19.4% | 350 |
| 22.2% | 400 |
| 24.9% | 450 |
| 27.7% | 500 |
Formula = mg/dL /18 = mmol/L
mmol/L x 18 = mg/dL
Increased Level Is Seen In:
- Newly diagnosed diabetic patient.
- Uncontrolled diabetic patient.
- Nondiabetic hyperglycemia is seen in:
- Cushing’s syndrome.
- Acromegaly.
- Corticosteroids therapy.
- Pheochromocytoma.
- Acute stress.
- Glucagonoma.
- Patient with splenectomy.
- Alcohol toxicity.
- Iron deficiency anemia.
- Lead toxicity.
Decreased HbA1c Level Is Seen In:
- Hemolytic anemia.
- Chronic blood loss.
- Chronic renal failure.
- Pregnancy.
Keywords: Glycohemoglobin A, Glycosylated Hemoglobin A, Hb A1, Hb A1a+b, Hb A1c, HbA1, Hemoglobin A(1), Hemoglobin A, Glycosylated, Glycosylated hemoglobin A, HBA GLYCOSYLATED, HBA 01, HEMOGLOBIN AA 01, HB AC 01, Haemoglobin A1c, HbA1c, HbA>1c<, Hemoglobin A1c, HbA1c, Hemoglobin A, Glycosylated [Chemical/Ingredient], hemoglobin a1c, hba1, hemoglobin a 1, glycosylated hemoglobin a, hb a1, hba1c, haemoglobin a1c, HbA1c (substance), HbA1c (substance), HbA>1c< (substance), HbA1 – Glycated haemoglobin, HbA1 – Glycated hemoglobin, Glycosylated haemoglobin A, Glycosylated hemoglobin A (substance)
Possible References Used
