Many diabetics know this dilemma: The next appointment for blood glucose measurement is coming up and the radical diet is supposed to compensate for the small dietary slip-ups and possibly lower the HbA1c value quickly so that the values appear normal again. This is a big mistake, because the long-term blood glucose value, the so-called HbA1c value, is decisive for good blood glucose control. Evidence from many large studies has shown that an improvement in HbA1c levels is associated with a reduced number of diabetes-related complications.
Vascular damage caused by diabetes
However, few diabetics know the exact meaning of this value. In fact, many people with diabetes don’t even know they have the disease. This results in a major problem: many years usually pass before diabetes is diagnosed, during which the blood sugar is often too high and the first fine vessels and nerves are already damaged as a result. This damage progresses insidiously and is hardly noticed by diabetics due to their reduced sense of pain. Not infrequently, these “small”, poorly noticeable changes end in the dreaded diabetes-related secondary diseases. But this need not be the case. Because studies show that good blood glucose control can reduce the risk of diabetes-related secondary diseases.
HbA1c – what does it mean?
The HbA1c value indicates the proportion of “sugared” red blood pigment (hemoglobin) in total hemoglobin. This stable “sugar hemoglobin,” known as “glycosylated hemoglobin” or “HbA1c” in technical terminology, is produced in everyone, not just diabetics, and is dependent on the average blood glucose concentration. Put simply, the higher the blood glucose level over a period of time, the higher the HbA1c level. With the HbA1c value, the doctor can determine the average blood glucose level over the last 8 to 10 weeks, regardless of whether the values have risen or fallen sharply in the meantime. This is why the HbA1c value is often referred to as the long-term blood glucose value. As early as 1999, the World Health Organization (WHO) recommended the HbA1c value, along with blood glucose measurement and the glucose tolerance test, as an important parameter for assessing the quality of diabetic control. The HbA1c value is therefore often referred to as the “gold standard” in diabetes therapy.
HbA1c – How high should the long-term value be in diabetes?
Whether the blood sugar is well adjusted can be seen from the HbA1c value. This is because the better the blood sugar is adjusted, the lower the HbA1c value. The HbA1c values at a glance:
- 4.5 – 6.5 percent: in healthy people, the HbA1c standard value is in this range.
- 6.5 – 7.0 percent: this is the HbA1c value in people with well-controlled diabetes.
- Above 7.5 percent: This is the HbA1c value above 7.5 percent in poorly controlled diabetics.
In general, the lower the HbA1c value, the lower the risk of secondary diseases. The current guidelines of the professional societies therefore recommend an HbA1c value of 7.5 percent in type 1 diabetes and an HbA1c value between 6.5 and 7.5 percent in type 2 diabetes for the prevention of diabetes-related secondary diseases. However, the exact assessment of the values in connection with all influencing factors should be made by the treating physician in each case.
Consequences of poorly controlled diabetes
Permanently high blood glucose levels, reflected in a high HbA1c value, lead to damage to the large and small blood vessels and to the nerves. Due to narrowed or even blocked vessels (arteriosclerosis), the tissue is no longer supplied with sufficient nutrients. The most common secondary diseases include diabetic foot, nerve damage, damage to the cardiovascular system, eye damage and damage to the kidneys.
The history of discovery of HbA1c
The introduction of the determination of HbA1c levels as a standard method was a critical advance in the control of effective diabetes therapy. The different variants of hemoglobin (HbA1, HbA2, and HbF) could be determined in 1955, followed by the separation and identification of the subtypes of HbA1 (HbA1a, HbA1b, and HbA1c) in 1958. The fact that in the case of HbA1c glucose bound tightly to hemoglobin was not proven until the 1970s. But as early as 1968, Dr. Samuel Rahbar, a pediatrician from Tehran, observed that an increased concentration of HbA1c was associated with diabetes.Quantitative detection of HbA1c gained importance when it could be proven that reduced blood glucose levels resulted in a reduction of the HbA1c value. The development of new determination methods and analytical procedures was enormously advanced in the following years and especially since the beginning of the 1980s. Today, modern laboratory methods allow the HbA1c value to be determined within minutes. This makes it easy to ensure close monitoring of the metabolic control of the diabetes patient
