RELATIONSHIP OF FASTING PLASMA GLUCOSE AND 2 HOURS AFTER BREAKFAST PLASMA GLUCOSE WITH THE RISING LEVELS OF GLYCOSYLATED HEMOGLOBIN IN PEOPLE WITH TYPE 2 DIABETES

Aim: To investigate the correlation of glycosylated hemoglobin (HbA1c) with fasting plasma glucose (FPG) and 2 hours after breakfast (2-hr ABF) plasma glucose with rising levels of HbA1c in patients with type 2 diabetes (T2DM).

Methods: The study was carried out on 664 patients reporting for routine follow up at a tertiary care hospital in the city of Dhaka, Bangladesh. The subjects were divided into 4 groups according to HbA1c levels: 1st group having HbA1c ≤6.5%, 2nd group having HbA1c of 6.6-7.5%, the 3rd group HbA1c 7.6-8.5% and the rest with HbA1c ≥8.6%. The Pearson correlation coefficient was used to investigate the relationship of HbA1c with FPG and 2-hr ABF plasma glucose.

Results: The correlation coefficient of HbA1c with FPG and 2-hr ABF plasma glucose in the 4 groups were (1) 0.055 and 0.179 at HbA1c level of ≤6.5%; (2) 0.236 and 0.291 at HbA1c between 6.6-7.5%; (3) 0.121 and 0.096 for HbA1c 7.6-8.5%; and (4) 0.510 and 0.397 for HbA1c level of ≥8.6%.

Conclusions: The correlation of HbA1c with 2-hr ABF plasma glucose is stronger than FPG at HbA1c level ≤7.5%; whereas the correlation of HbA1c with FPG is stronger than 2-hr ABF plasma glucose at HbA1c levels of ≥7.6%. The contribution of a given FPG and post-prandial glucose value to overall glycemia varies depending on the HbA1c results.