Before going into the hbA1C details, you should know about blood, RBC, and hemoglobin.
A blood drop contains more than million red blood cells (RBC or erythrocytes). Each RBC contains over 600 million hemoglobin.
What is RBC (red blood cell)?
RBC or erythrocyte is biconcave-disk with a flat center with indentation. RBC looks similar to a donut without a hole. This RBC shape provides greater surface area to carry fresh oxygen throughout the body. The life span of RBC is about 120 days.
What is hemoglobin?
Hemoglobin is a protein in the red blood cells. It carries oxygen to every cell in your body. Hemoglobin provides red color to the red blood cell; it contains an iron atom at its center. RBC is red in color when iron atom bind to oxygen; otherwise (when iron does not bind to oxygen) blue-red in color.
What is Glycation of Hemoglobin HbA1C?
Other names of A1C are hba1c, glycated hemoglobin, hemoglobin A1C, and glycated hemoglobin A1C. Some people call it as A1C diabetes and A1C measurement. Sometimes people wrongly called it as glycosylated hemoglobin, hga1c, ha1c, hemoglobin 1ac, and hemoglobin h1c.
Glycated hemoglobin is formed when glucose in the blood chemically reacts with hemoglobin. That is glucose got attached to hemoglobin.
Imagine, you are rolling new hard gum or donut over a tray containing sugar. The sugar sticks to the hard gum or donut. Likewise, glucose in the blood stick to the hemoglobin, this reaction is called glycation.
The glucose concentration in the blood decides the extent of hemoglobin glycation. This glycation process is irreversible, and it stays for its entire life.
A1C reflects the hemoglobin glycation that is proportional to average glycemia. However, you should not expect every individual glycated to the same degree for a given level of glycemia.
What is A1C diabetes test?
A1C test results show the percentage of glycated hemoglobin. An A1C of 5% indicates; out of 100 hemoglobin, 5 of them are glycated (glucose attached to it).
HbA1C test measures the percentage of hemoglobin attached to the glucose in the blood. The glucose level decides the rate of glycation in the blood.
The lifespan of red blood cells is approximately 90 days. So, the percentage of hemoglobin A1C correlates to the average blood glucose for the last 90 days.
Glycated hemoglobin test shows the level of glucose in the blood for the past two to four months. Measuring A1C helps to access the effectiveness of diabetes treatment.
Why is it called as HbA1C? Because it measures the percentage of glycated hemoglobin variant "A" subtype "1c" in blood. "Hb" is for hemoglobin, "A" is variant and "1C" is a subtype.
What is the difference between glycosylation and glycation?
Glycosylation is an enzymatic process of bonding of glucose with protein (or lipid) molecule. Glycosylation is an important biological process does many vital functions. These functions are proper protein folding, increased protein stability, substrate binding, and solubility. Glycosylation is a normal part of cell function; it does not have a link with the aging process.
However, glycation is an unregulated chemical (not enzymatic) process of sticking glucose with protein. This glucose denatured the protein; this contributes many diseases of aging. It develops chronic vascular complications, non-diabetic nephropathy, vascular disease, Alzheimer’s disease, and aging.
Danger of glycation
Typically, glucose provides energy to the cells. However, in insulin resistant individuals, the insulin cannot effectively push glucose into the cells. Thus glucose stay in the blood, and later denature the proteins in the body.
Hyperglycemia increases the rate of glycation and increased risk towards diabetes complications. Some common diabetes complications are blindness, renal and vascular disease. The glycated molecule may develop into advanced glycation end products (AGEs). AGEs accumulation in the eyes, kidneys, arteries, nerve endings, joints, and skin leads to many health issues.
Why people with diabetes prone to flu and other infections?
Viruses use glycosylation or glycolation to shield the underlying viral protein from immune recognition. Viruses (such as HIV, Epstein-Barr virus, etc.) rely on glycosylation either for infection, replication, and immune evasion. Viruses exploit host glycosylation to ensure their propagation and survival.
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A1C test, how do I take?
The A1C test is a simple blood test, fasting not required! You can eat as usual, without restriction.
The hba1c test can perform with a regular finger stick using lancing device or by blood sample drawn from a vein. For A1C test, you can take blood sample at any time of the day. Home A1C testing is available; if you do not follow the instruction, the test may result in inaccuracy.
What are the different methods to measure HbA1C?
There are four fundamental ways to measure HbA1c. They are Immunoassay, Ion-exchange high-performance liquid chromatography (HPLC), Boronate affinity HPLC, and Enzymatic assays.
Laboratories should be aware of their limitations that interference from the most common Hb variants. They can select new methods that are less likely to have interference. A result not fit to the clinical picture need further investigation with the clinician.
Ask your doctor if the lab running the test uses a method certified by the NGSP. Sadly, not every laboratory or home test kit meet those standards. List of NGSP Certified Laboratories.
Why is HbA1c measurement important?
HbA1c gives valuable information for diabetics. HbA1c do not fluctuate a lot, why? Once red blood cells are glycated, it stays there for its entire life (3 months). So, HbA1c gives an overall picture of blood glucose control for past three months. The hba1c number is the best-proven marker of a risk towards diabetes complications.
Downside of the A1C test
A significant disadvantage of the A1C test is
• A person’s blood sugar consistently healthy and
• Another person’s blood sugar fluctuate high and low,
Could have the same A1C test result. So, for effective diabetes management undergo both A1C and self-monitoring blood glucose (SMBG) tests.
Why do you need to take both SMBG and A1C test?
Blood glucose fluctuates; from seconds to seconds; minute to minute; hour to hour; and day to day. The A1C has changed slowly for past 8 to 10 weeks. So it is useful as a 'quality control' test.
So, why should I measure blood glucose level?
Blood glucose test provides freely available sugar concentrations in the blood at that moment. So, it help detecting hypoglycemia or hyperglycemia. It allow to take appropriate treatment changes; e.g. insulin, food intake and activity levels.
Monitoring blood sugar allows to make quick adjustment. Thus, helps to achieve tight diabetes control and healthy A1C. Additionally, it lower or eliminate many diabetic complications.
Diabetic’s blood glucose level fluctuates more than the healthy individuals. Blood sugar level elevates after food, especially sweet, refined carbohydrates, and carbohydrate rich foods. BS drops after exercise, and unpredictable after stress. For diabetics, this makes it difficult to maintain sugar levels. Thus, for immediate real-time correction, the glucose level measurement is the best.
In summary, both BS and A1C tests are necessary for immediate and long-term BS info. It helps in the decision making for proper diabetes management.
If you self-monitor your glucose today and treat accordingly, contribute to achieving optimal A1C later. A1C & glucose tests are inter-related, and regular BS measurement is necessary to attain healthy A1C.
Research shows improving both BS and A1C is important to avoid micro & macrovascular diabetes complications.