| Abstrakt: |
The major utility of the glycosylated hemoglobin assay continues to be as a monitor for the effectiveness of diet/insulin or oral agent therapy in the normalization of serum glucose concentrations. During periods of poor glycemic control, as assessed by frequent positive urine glucose determinations, or by elevated fasting or postprandial blood glucose concentrations, or by episodes of ketoacidosis, the use of the glycosylated hemoglobin assay adds little information. Rather, it is most useful during periods of stable control, to assess the effectiveness of the combined therapy of diet, activity, and insulin or oral agents. As the glycosylated hemoglobin concentrations tend to reflect the metabolic control during the previous four to eight weeks, little is to be gained from more frequent use of this assay. An isolated elevated serum glucose concentration obtained in the office or hospital laboratory, associated with a near-normal serum glycosylated hemoglobin concentration need not demand drastic rearrangement of the patient's therapuetic regimen. The normal hemoglobin A1cconcentration reflects good blood glucose control over the past one to two months. The elevated blood glucose concentration may reflect a transient aberration secondary to stress, diet, or other factors. If, however, actual deterioration in the patient's metabolic control is occurring, this may not be reflected in the hemoglobin A1cconcentration for several weeks or months. Likewise, during a period of stable control, a normal office or lab glucose concentration associated with an elevated glycosylated hemoglobin concentration may indicate poor control, the normal glucose resulting from the peak effectiveness of either short- or intermediate-acting insulin. In this situation, more frequent glucose determinations would reveal elevation of blood glucose concentrations. |
