What are the values for diabetes?
In Europe, blood glucose is usually measured in milligrams per deciliter (mg/dl). Internationally (especially in the USA), however, it is measured in millimoles per liter (mmol/l).
The most important values are fasting blood glucose and HbA1c. The latter is also referred to as “blood glucose long-term memory”. In addition, abnormal values in the oral glucose tolerance test (oGTT) indicate a diabetes precursor (“prediabetes”) or diabetes. Detection of sugar in the urine is also used for diagnosis.
Diabetes: At what level is it dangerous?
First things first: the great danger with diabetes mellitus is that blood sugar levels can become dangerously derailed and – in extreme cases – a diabetic coma is imminent. Sugar levels above 250 mg/dl (13.9 mmol/l) are an alarm signal for hyperglycemia. In the case of hypoglycemia, they are below 70 mg/dl (3.9 mmol/l).
When is diabetes diagnosed?
| Fasting blood glucose | oGTT: 2-Std value | HbA1c (%) | |
| Healthy | < 100 mg/dl | < 140 mg/dl | 4.5 to 5.7 |
| < 5.6 mmol/l | < 7.8 mmol/l | ||
| Impaired glucose tolerance | 100 – 125 mg/dl | 140 – 199 mg/dl | 5.7 to 6.4 |
| 5.6 – 6.9 mmol/l | 7.8 – 11 mmol/l | ||
| Diabetes mellitus | ≥ 126 mg/dl | ≥ 200 mg/dl | ≥ 6,5 % |
| ≥ 7 mmol/l | ≥ 11.1 mmol/l |
Fasting blood glucose
Fasting blood glucose is the most important of the diabetes blood values for diabetes diagnosis. It ranges from 60 to 99 mg/dl or 3.3 to 5.6 mmol/l in healthy individuals. If the fasting blood glucose is between 100 and 125 mg/dl, this is already referred to as abnormal fasting glucose (IFG = impaired fasting glucose). Values above 125 mg/dl are very likely to indicate diabetes mellitus. To rule out incorrect measurements, the value is usually determined a second time.
Diabetes – HbA1c (long-term blood glucose value)
In both healthy individuals and diabetics, sugar molecules attach themselves to part of the red blood pigment (hemoglobin). The sugar-laden hemoglobin is called glycohemoglobin A (also HbA1c). Normally, however, no more than 5.7 percent of hemoglobin has a sugar molecule attached to it.
Due to permanently elevated blood glucose levels, a higher proportion of hemoglobin in diabetics is loaded with a sugar molecule. Since red blood cells live for an average of about 120 days, the HbA1c value is suitable as a diabetes long-term value and thus provides information about the blood glucose control of the last eight to twelve weeks. Individual daily fluctuations do not influence the HbA1c value. HbA1c is determined primarily to monitor the success of treatment.
Oral glucose tolerance test (oGTT)
After 120 minutes, a new blood sample is taken to determine the blood glucose level. This two-hour value provides an indication of how much of the glucose absorbed from the blood has been absorbed into the cells with the help of insulin. If two-hour values exceed 200 mg/dl, diabetes mellitus is very likely. If diabetes is known, the oGTT should not be used to avoid derailing blood glucose levels.
Desired diabetes values during the course of treatment
The blood glucose values to be aimed for are always discussed individually with the treating physician. This is because they differ depending on the patient’s constitution and age. However, the normal diabetes values recommended by the German Diabetes Society apply to most patients. They differ only slightly in type 1 diabetics and type 2 diabetics.
Diabetes type 1 values
Diabetes type 2 values
In type 2 diabetes, treatment is controlled by the fasting blood glucose value as well as the HbA1c value. In a type 2 diabetic, the fasting blood glucose value before a meal is between 80 and 120 mg/dl at best. If it is higher, the medication must be adjusted.
If concomitant diseases such as high blood pressure (hypertension), kidney damage (nephropathy) or a disorder of the fat metabolism (hyperlipidemia) are present, these must be treated as well, since excessively high blood glucose levels aggravate these diseases. An HbA1c value between 6.5 and 7.5 percent is recommended. The individual needs of patients are also taken into account. For example, it is possible that an HbA1c value of 8.0 may still be tolerable in older patients.
Which diabetes values apply during pregnancy?
- Fasting blood glucose: 92 mg/dl (5.1 mmol/l)
- Blood glucose after one hour: 180 mg/dl (10.0 mmol/l)
- Blood glucose after 2 hours: 153 mg/dl (8.5 mmol/l)
In both pregnant and non-pregnant patients, it is important to monitor diabetes levels regularly.