Hemoglobin to which glucose is bound. Glycosylated hemoglobin is tested to monitor the long-term control of diabetes mellitus.
The level of glycosylated hemoglobin is increased in the red blood cells of persons with poorly controlled diabetes mellitus. Since the glucose stays attached to hemoglobin for the life of the red blood cell (normally about 120 days), the level of glycosylated hemoglobin reflects the average blood glucose level over the past 3 months.
The normal level for glycosylated hemoglobin is less than 7%. Diabetics rarely achieve such levels, but tight control aims to come close to it. Levels above 9% show poor control, and levels above 12% show very poor control. It is commonly recommended that glycosylated hemoglobin be measured every 3 to 6 months in diabetes.
The Diabetes Control and Complications Trial (DCCT) showed that diabetics who keep their glycosylated hemoglobin levels close to 7% have a much better chance of delaying or preventing diabetes complications that affect the eyes, kidneys, and nerves than people with levels 8% or higher. A change in treatment is almost always needed if the level is over 8%. Lowering the level of glycosylated hemoglobin by any amount improves a person’s chances of staying healthy.
Glycosylated hemoglobin is also known as glycohemoglobin or as hemoglobin A1C (the main fraction of glycosylated hemoglobin).
The presence of free hemoglobin in the urine, which may make the urine look dark. Normally, there is no hemoglobin in the urine. Hemoglobinuria is a sign of a number of abnormal conditions, such as bleeding and paroxysmal nocturnal hemoglobinuria.
The word “hemolysis” is made up of “hemo-“, blood + “lysis”, the disintegration of cells.
The word “hemolytic” is made up of “hemo-“, blood + “lytic”, the disintegration of cells.
- Hemolytic anemia
Anemia due to the destruction, rather than underproduction, of red blood cells. Hemolytic anemia can result from a medication reaction, from the immune system attacking the red blood cells (autoimmune hemolytic anemia), from destruction of blood cells passing through diseased heart valves, and other causes.
- Hemolytic disease of the newborn
Abnormal breakup of red blood cells in the fetus or newborn. This is usually due to antibodies made by the mother directed against the baby’s red cells. It is typically caused by Rh incompatibility, that is differences between the Rh blood group of the mother and baby. Severe hemolytic disease can cause anemia and heart […]