Glycosylated haemoglobin: an overview of a series of clinical studies.

A series of studies on the clinical relevance of chromatographically determined glycosylated haemoglobins is presented. Both whole blood samples and haemolysates were stable at 5 degrees C for up to two weeks. Prolonged storage required temperatures less than -80 degrees C. Haemoglobin (Hb) AIc percent values in non-diabetic subjects ranged from 4.0 to 6.0 percent (mean +/- 2 SD). HbAIc percent values proved to be as stable in diabetic as non-diabetic subjects on repetitive sampling over a three month period. A dissociable component was not observed in any of 78 samples. HbAIc percent values of carbohydrate intolerant subjects (n = 18) were not distinguishable from those in non-diabetic subjects. A close correlation was observed between HbAIc percent and the mean of multiple capillary glucose samples in 37 insulin dependent diabetic subjects. In clinical practice HbAic percent proved to be a stable objective measure of blood glucose concentrations in diabetic patients--the major present need is for a simple reliable technique of measurement.