Glycosylated hemoglobin in the diagnosis of non-insulin-dependent diabetes mellitus.

Fifty-one patients aged over 35 yr were referred because of glycosuria for a glucose tolerance test (GTT). In each patient hemoglobin A1 (HbA1) was estimated by a commercial minicolumn method and compared with hemoglobin A1c (HbA1c) determined by a modification of the method of Trivelli et al. Both HbA1 and HbA1c levels were normal in 96% of those patients with normal GTTs. In patients with diabetic GTTs, HbA1 was elevated in 90% but HbA1c was raised in only 43%. HbA1 estimation is a useful screening test for non-insulin-dependent diabetes and should be considered when criteria for diagnosis of diabetes mellitus are discussed.