Hemoglobin A1c compared with three conventional measures of diabetes control.

Control of diabetes was studied during an 8-wk camp program in 18 insulin-dependent counselors with a mean age of 19.3 yr and a mean duration of diabetes of 11.4 yr. A composite score was obtained for each subject derived from three factors: percent sugar-free urine tests, 24-h glucose excretion as percent of carbohydrate intake, and mean preprandial blood glucose (MPBG). The mean hemoglobin A1c (HbA1c) at the end of the period was 8.3 +/- 1.6% (+/ SD) (normal range, 4-6%). Scores ranging from 24 (fair control) to 45 (excellent control) showed a significant inverse correlation with HbA1c (r = 0.807, P less than 0.001) and MPBG (r = -0.674, P less than 0.01). HbA1c showed a significant correlation with the MPBG (r = 0.693, P less than 0.01). The HbA1c level was predicted better by percent sugar-free urine tests than by the 24-h glucose excretion. Thus it appears that accurate quantification of control may be obtained by using a scoring system. Critical comparison of HbA1c levels to various glycemic indices may provide useful alternatives for estimating diabetes control.