Interindividual divergence in the relationship between the values of plasma glucose and hemoglobin A1c in type 2 diabetes.

OBJECTIVE To verify the relationships between the values of plasma glucose (PG) and hemoglobin A(1c)(HbA(1c)) in type 2 diabetic outpatients. METHODS The pre- and postbreakfast PG and HbA(1c) values were monitored every month for 44-90 months. The single regression lines between the values of PG and HbA(1c) were compared for the slopes and intercepts on the designated ordinates of the regression lines. PATIENTS OR MATERIALS Nine patients of type 2 diabetes not treated with insulin: three males and six females, aged 43-79 years participated. RESULTS The HbA(1c) level was combined with the pre- and postbreakfast PG values obtained at one month prior to its determination, because the combinations were correlated most strongly. The slopes of the regression line ranged from 0.33-0.50%/mmol/L and the intercepts at PG level equal to 9.6 mmol/L ranged from 6.95-9.77% in the relationship between the values of 1-month earlier prebreakfast PG and HbA(1c). Twenty-eight pairs had significantly different intercepts. Meanwhile, there was no pair that had significantly different slopes. Similar results were obtained in the relationship between the values of 1-month earlier postbreakfast PG and HbA(1c). CONCLUSION There was interindividual divergence of the regression lines which was due to the difference in the intercepts but not the slopes.