HbA1c

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:

1. This test is used to monitor diabetes control.
2. This test tells us the patient average glucose index over a long period of time (2 to 3 months).
3. It tracks glucose in the milder form of diabetes.
4. It helps to determine which type of drugs may be needed.
5. 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.
6. It should be repeated every 3 to 4 months.

Sample Required:

1. The blood sample is taken in the EDTA 3 to 4 ml.
2. Washed RBC or hemolysate is prepared and this is stable for 4 to 7 days at 4 °C.
3. 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

1. Non Diabetic adult = 2.2 to 4.8 %.
2. Non Diabetic child = 1.8 to 4.0 % .
   1. Prediabetic              = 5.7 to 6.4 %
   2. Diabetics                  = >6.5 %
   3. Diabetic HbA1c = > 8.1 % = corresponds with glucose >200 mg/dl.

Diabetic Control And HbA1c

1. Good diabetic control = 2.5 to 5.9 %.
2. Fair diabetic control = 6 to 8 %.
3. 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:

1. Newly diagnosed diabetic patient.
2. Uncontrolled diabetic patient.
3. Nondiabetic hyperglycemia is seen in:
   1. Cushing’s syndrome.
   2. Acromegaly.
   3. Corticosteroids therapy.
   4. Pheochromocytoma.
   5. Acute stress.
   6. Glucagonoma.
4. Patient with splenectomy.
5. Alcohol toxicity.
6. Iron deficiency anemia.
7. Lead toxicity.

Decreased HbA1c Level Is Seen In:

1. Hemolytic anemia.
2. Chronic blood loss.
3. Chronic renal failure.
4. 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, HbA_1c, Hemoglobin A, Glycosylated [Chemical/Ingredient], hemoglobin a1c, hba1, hemoglobin a 1, glycosylated hemoglobin a, hb a1, hba1c, haemoglobin a1c, HbA_1c (substance), HbA1c (substance), HbA>1c< (substance), HbA1 – Glycated haemoglobin, HbA1 – Glycated hemoglobin, Glycosylated haemoglobin A, Glycosylated hemoglobin A (substance)

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Possible References Used

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