Glycosylated Hemoglobin Assay Research Articles

Recent advances in glycosylated hemoglobin measurements.

Glycosylated hemoglobins have gained wide acceptance as an accurate index of long-term blood glucose control in diabetes mellitus. A variety of glycosylated hemoglobin assays is available. There is a high degree of correlation between results determined by these assays. The ideal laboratory method for measuring glycosylated hemoglobin in the diabetic should be accurate, precise, easily standardized, inexpensive, and rapidly performed. Unfortunately, none of the currently used methods meet all of the criteria necessary to be considered the ideal laboratory method. The most widely used methods for quantitating glycosylated hemoglobins--including ion exchange chromatography, electrophoresis, isoelectric focusing, thiobarbituric acid colorimetry, and affinity chromatography--are reviewed with respect to the important advantages and disadvantages of each method for the clinical laboratory. Techniques for quantitating glycosylated proteins other than hemoglobins, such as albumin, are also discussed.

Childhood Diabetes and Intensive Insulin Therapy

To the Editor.— The article by Geffner et al 1 stressed the importance of self-monitoring of blood glucose levels and intensified insulin administration in achieving improved glycemic control. However, I wish to take issue with the impression created that multiple insulin injections daily were mandatory in attaining this goal. In my own pediatric diabetic population, there exists a group of patients whose conditions are well controlled with single daily injections of combined intermediate- and short-acting insulin. These patients have had the following characteristics: (1) nonbrittle diabetes, (2) well-motivated and well-informed parents, (3) carefully planned diets, (4) frequent home blood glucose monitoring, (5) regular glycosylated hemoglobin assays, and (6) close physician supervision. Additional doses of regular insulin are occasionally required as indicated by the blood glucose values. Multiple doses of insulin daily can be a traumatic experience to the parent and child, especially in the 1- to 5-year age group. If

The value of good control.

There is still little agreement about the meaning of diabetic control and how to attain and maintain degrees of control close to the non-diabetic state. Variations in blood glucose within the day, measures of unpredictability (“brittleness”) from day to day and glycosylated haemoglobin assay contribute to our understanding of glycaemic control. However, criculating concentrations of many other intermediary metabolites and hormones are disordered in diabetes and should also be taken into account. The best conventional insulin regime which is readily acceptable to the patient is probably a mixture of short and intermediate acting insulin given twice daily, with self-monitoring of blood glucose and adjustment of dose according to values obtained. Continuous subcutaneous insulin infusion (CSII) with a dual rate, portable syringe pump, is a new, still experimental, approach to achieving long term metabolic near-normalisation in insulin-dependent diabetics. In long standing diabetics with increased microalbuminuria, strict control for just a few days reduced or normalised urinary albumin excretion. Some preliminary results in diabetics with severe retinopathy showed encouraging response to several months of good control by CSII. Furthermore, long periods of good control may improve remaining β-cell function in newlydiagnosed insulin-dependent diabetics. A high priority must, therefore, be given to prospective trials testing the effects of metabolic near-normalisation on the evolution of diabetic tissue complications and, in particular, microangiopathy.

Glycosylated hemoglobin assay and oral glucose tolerance test compared for detection of diabetes mellitus.

We compared the oral glucose tolerance test (I) as evaluated by six commonly used scoring methods and total glycohemoglobin assay (II) with respect to their value in the diagnosis of diabetes mellitus. Depending on the evaluation method used for I, 16.7 to 64.3% of those subjects diagnosed as diabetic or borderline by this test were judged to be normal by II. The best agreement was between II and the Unger evaluation method. High-density-lipoprotein cholesterol, which showed an inverse correlation with II, was decreased in subjects judged to be diabetic by the Unger method. We conclude that the utilization of II measurement as a screening method for diabetes mellitus is consistent with a conservative approach to the diagnosis of diabetes.