Glycosylated hemoglobin in a population-based study of diabetes.

Glycosylated hemoglobin was measured in persons who participated in a population-based study of diabetic retinopathy in southern Wisconsin. There were 996 persons who were diagnosed prior to 30 years of age and who were taking insulin (younger onset), and 1,370 persons who were diagnosed at 30 years of age or older (older onset) who were examined from 1980-1982. Glycosylated hemoglobin was measured using a microcolumn technique. Mean glycosylated hemoglobin was highest in younger onset persons (10.9%), and lowest in older onset persons not taking insulin (9.0%). Only a small percentage of values for the diabetic persons fell within the range of values found in a nondiabetic comparison group. Mean glycosylated hemoglobin was found to be associated with retinopathy status but not with proteinuria.