Glycosylated hemoglobins and long-term blood glucose control in diabetes mellitus.

The glycosylated minor hemoglobin components Hb A1a+b and HbA1c are elevated in insulin-dependent juvenile diabetic patients, 3.2+/-0.7 (+/-1 SD) and 10.0+/-1.9% of total hemoglobin respectively, versus 2.1+/-0.4 and 4.9+/-0.7% in a normal non-diabetic control population. Total glycosylated hemoglobin components, Hb A1a+b+c, correlated with the degree of diabetic blood glucose regulation as measured by antecedent 24-h urinary glucose excretion determined in 220 diabetic patients immediately before, 1, 2, and 3 months prior to the HB A1a+b+c measurement. This assay for long-term blood glucose regulation was utilized to determine the effect of hyperglycemia on plasma cholesterol levels in 112 diabetic patients. Hb A1a+b+c levels correlated with plasma cholesterol levels, suggesting that long-term hyperglycemia is associated with hypercholesterolemia. It is suggested that glycosylated hemoglobin measurement is a good index of long-term blood glucose levels in diabetic patients.