Correlation of HbA1c and postprandial glycemia during a standard breakfast test in patients with type 2 diabetes receiving glibenclamide

Aim. To analyze the effect of glibenclamide on carbohydrate metabolic parameters, glucose values after standard breakfast in particular, in patients with type 2 diabetes (T2D).
Subjects and methods. Thirty patients aged 57.6±9.4 years with a 4.4±4.0-year history of T2D received glibenclamide in a daily dose of 10.9±4.4 mg in combination with diet therapy for 3 months. Venous plasma glycemia was determined before and at the end of the fasting test, 60 and 120 minutes after a standard breakfast test.
The area under the glycemic curve was calculated using the trapezoidal method during the standard breakfast test. Out of all possible formulas reflecting a blood glucose increase in relative values during the test, there were two most acceptable formulas that were chosen for further calculations: 1) the contribution of postprandial glycemia exceeding fasting glycemia to postprandial glycemia exceeding 6.1 mmol/l (OS1/2); 2) that of postprandial glycemia exceeding the glycemia of 6.1 mmol/l to postprandial glycemia in the standard breakfast test (OS2/S).
Results. Follow 3-month therapy, glycated hemoglobin (HBA1c) decreased from 8.7±1.8 to 7.0±1.0% (p < 0.0001), fasting plasma glucose reduced from 9.8±2.7 to 8.3+-1.7 mmol/l (p < 0.01); it decreased from 14.8±3.9 to 13.2+-3.3 mmol/l (p < 0.01) and from 13.3±3.6 to 11.1+-3.0 mmol/l (p < 0.02) 1 and 2 hours after the load test, respectively. There was a significant reduction in the total area under the glycemic curve (S) - from 1583.5±405.8 to 1375.7+-320.1 mmol/lmin. However, there were no significant changes. There was a significant increase in the relative value OS1/2 from 51.7±17.7 to 62.8±20.0% and a significant reduction in OS2/S. Analysis of the area in relative values (OS1/2 and OS2/S) obviates the ambiguousness of the results obtained when analyzing the area in absolute values.
Conclusion. Glibenclamide treatment causes a statistically significant reduction in fasting and postprandial plasma glucose levels, glycated hemoglobin, and relative area values during the standard breakfast test.

HbA1c, type 2 diabetes, postprandial glycemia, HbA1c, standard breakfast test