Glycosylated hemoglobin : norm and pathology
Analyses And Studies / / May 01, 2016
- Reasons for increasing HbA1C
- How to be tested for HbA1C?
- Decoding result
glycosylated hemoglobin - what it is, its normal value
oxygen transport and carbon dioxide by means of a specific protein (hemoglobin), which is contained in erythrocytes (red blood cells).Glucose in the blood which is in the dissolved state partially connected to hemoglobin without enzymes (non-enzymatic chemical reaction) forming its glycosylated fraction (HbA1C).An increase in blood sugar, this process is much faster, increasing the concentration of glycosylated (glycated) hemoglobin.Considering that the average life of red blood cells is 90
Reasons for increasing HbA1C
glycosylated hemoglobin in the blood increases due to prolonged increase of sugar in it, which develops in diabetes:
- insufficient production of the hormone insulin by the pancreas (type 1) - is the main hormonewhich acts on specific cell receptors, leading to increased glucose utilization.Deterioration
- response to insulin (type 2) cell receptors - wherein during normal production and the level of blood sugar rises anyway.
also HbA1C definition shows the effectiveness of therapy aimed at lowering glucose.Increasing this fraction can occur under the influence of causes unrelated to the increase in sugar:
- Iron deficiency anemia - HbA1C increased relative reduction in the total level of hemoglobin.
- Splenectomy - removal of the spleen, which increases the average life span of red blood cells, resulting in the accumulation of glycosylated fraction.
- intoxication of the organism in case of poisoning, alcohol, salts of heavy metals or uremia (accumulation in the body in patients with renal insufficiency cellular metabolism products).
Somewhat less decrease in HbA1C fraction may be lower than normal blood transfusion (not diluting the glycosylated fraction), severe blood loss, reducing the lifespan of red blood cells (hemolytic anemia) and a decrease in long-term glucose levels.
HbA1C blood test to show for objective investigation of the state of the sugar metabolism in such cases:
- detection of diabetes of any type;
- evaluating the effectiveness of treatment aimed at reducing glucose;
- gestational diabetes - women during pregnancy is a significant part of the glucose enters the body of the growing fetus, so for an objective diagnosis of glucose metabolism disorders determine HbA1C;
- definition of violations of carbohydrate metabolism in children, which is not associated with changes in insulin levels;
- diagnosis other causative factors of increasing glucose - adrenal tumors, which lead to an increase in the production of glucocorticoids enhancing glucose, liver pathology intensive cleavage of glycogen to glucose and increasing its levels in the blood.
How to be tested for HbA1C?
definition of this indicator is carried out in a clinical diagnostic laboratory.To do this, from a vein (usually Vienna elbow) is taken into the blood volume of about 5 ml, where with the help of a special biochemical analyzer determined kontsentratsiyaHbA1C.To monitor the effectiveness of therapy of high sugar, this analysis shall every 3-4 months.No special training or implementation of the recommendations in this laboratory research is not required, in contrast to the usual analysis for sugar, which necessarily need to take on an empty stomach.
Increased glycated fraktsiina 1% above normal, indicative of long-term increase in glucose 2-2.5 mmol / l.Depending on the degree of increase of hemoglobin fractions can draw conclusions about the general state of carbohydrate metabolism:
- 6-7% - pre-diabetes may develop diabetes in the future, you should pay attention to diet, to reduce the consumption of carbohydrates (sweets, pastry);
- 7-8% - symptomatic diabetes, in which it is imperative to take measures aimed at reducing sugar as possible complications (retinopathy, diabetic foot);
- more than 10% - severe decompensated form of violation of carbohydrate metabolism with the development of complications and the need for comprehensive treatment.
Through the study of HbA1C level there is a possibility of early detection of sugar metabolism disorders, to the development of its complications, and follow-glucose-lowering therapy.Assigns the passage of this analysis endocrinologist, family doctor or therapist at the slightest suspicion of violation of carbohydrate metabolism.