Do I need to fast to measure glycosylated hemoglobin?

Diabetic patients need to test the concentration of glycosylated hemoglobin. Sometimes the hemoglobin value detected when fasting will be too high or too low. This is determined by several factors. Sometimes, exercise, sweating, etc. will have a certain impact on the hemoglobin value. Only the testing of glycosylated hemoglobin can clearly reflect the average blood sugar level within three months. Many people have certain misunderstandings about glycated hemoglobin testing. Let’s take a look.

Myth 1

The closer the value is to normal, the better

Many patients believe that the closer the glycated hemoglobin is to normal values, the better (the normal value range of the standard detection method is 4% to 5.9%). This understanding is incomplete. Diabetes treatment emphasizes the principle of individualization, and the control standards for glycosylated hemoglobin vary from person to person. Sometimes, for those with severe conditions, blindly pursuing low glycosylated hemoglobin values ​​may not be worth the cost.

Myth 2

Glycated hemoglobin and blood sugar monitoring alone is enough

Glycated hemoglobin and self-blood glucose monitoring are not mutually exclusive, but complementary. Both have their own advantages and disadvantages for the follow-up of diabetic patients. Compared with random blood sugar, the glycated hemoglobin test value is not affected by temporary accidental factors and has nothing to do with whether the patient is fasting when blood is collected, so it is more stable. Blood sugar can reflect the immediate situation, especially through multi-point blood sugar monitoring (blood sugar profile), it can reflect the patient's blood sugar fluctuations and control throughout the day.

Myth 3

Glycated hemoglobin always reflects the real situation

Generally speaking, the changing trends of blood sugar and glycosylated hemoglobin are consistent, but sometimes the changes between the two are inconsistent. For example, in the case of fulminant type 1 diabetes, glycosylated hemoglobin may not keep up with the speed of acute blood sugar changes, and therefore cannot reflect the true average blood sugar level. Alcoholism, iron deficiency anemia, and hypertriglyceridemia can also increase glycated hemoglobin. Pregnant women have increased blood volume and decreased hemoglobin, and those with hemolytic anemia, acute or chronic blood loss, chronic renal failure, hemoglobinopathy, etc., will have lower measured glycosylated hemoglobin values.

Myth 4

Fasting is required for testing glycosylated hemoglobin

Glycated hemoglobin is not affected by meals, and blood can be drawn at any time for testing, without the need for fasting. However, for patients with anemia and hemoglobin disorders, the results of glycosylated hemoglobin test are unreliable, and blood glucose, glycosylated serum albumin or glycosylated serum protein should be used to evaluate blood glucose control.

Myth 5

Diabetics need to test glycosylated hemoglobin from time to time

Glycated hemoglobin is the "gold standard" for diabetes monitoring, but it is not necessary to test this indicator frequently. Patients with newly diagnosed diabetes need to undergo glycosylated hemoglobin testing; for patients whose blood sugar control is stable and meets the target, glycosylated hemoglobin can be measured twice a year; for patients whose treatment plan changes or whose blood sugar control fails to meet the target, it is best to measure glycosylated hemoglobin once a quarter.