Glycated hemoglobin /HbA1 c, middle level of glucose in blood for 3 months.

 Molecule of glucose having tendency to attach to hemoglobin. That  test defines of molecules a glucose, which connected to hemoglobin and forming glycated hemoglobin. When molecules of glucose connecting with hemoglobin , a glycated hemoglobin keeping within an al life of date a erythrocyte , which in healthy peoples having are 120 days.Thus, analyses of erythrocytes and theirs glycated hemoglobin showing a middle glucose level in blood of patient for this period. 

Ideal or optimal level for HbA1c is to 20 percents.

Normal level for HbA1c are 3.5- 5.6 perc.

Pre-diabetes  is will to diagnose , if level of HbA1c is staying on limited  5.7-6.4 perc.

HbA1c > 6.5 perc. usually confirmed  a diabetes  having.

Diagnostical sensitive of HbA1c is having  60 perc, thus ,that 40 perc of patients with a high glucose level on an empty stomach or destroyed tolerance to glucose is keeping not diagnosed. Thus, a means, that   one this test is not enough for diagnosis destroying metabolism of glucose, and in here hiding reason for delaying diabetes diagnosis:doctors are habit reliance on results of special rests, but they are often  forgetting ,that these tests are not beining on 100 percents an accurate , and in data case of percents an inaccuracy is very high. A one from researches are showed, that in  comparison with measuring glucose level on an empty stomach  and GTT ,HbA1c was been false negative on 64 perc cases a pre- diabetes , and 75 percents of cases a diabetes, and false positive result shown 20.1 perc in pre- diabets and 0.6 perc. in diabetes.

 Hemoglobinopathia, anaemia, blood lost,,  malaria , high triglycerides high level, chronic liver diseases, and a few remedies causing a false low level for HbA1c , but from other side an iron deficit , insufficient vitamin B12, alcoholism, uremia, hyperbilirubinemia, and  a few remedies are causing a high level for HbA1c.