Metformin decreases glycated albumin to glycated haemoglobin ratio in patients with newly diagnosed type 2 diabetes.

Background: To know whether metformin improves postprandial hyperglycaemia, we examined the effect of metformin on the glycated albumin (GA) to glycated haemoglobin (HbA1c) ratio (GA/HbA1c ratio) in patients with newly diagnosed type 2 diabetes.

Methods: Metformin and lifestyle interventions were initiated in 18 patients with newly diagnosed type 2 diabetes. Metformin was titrated to 1500 mg/day or maximum-tolerated dose. HbA1c and GA were measured every four weeks up to 24 weeks.

Results: HbA1c decreased significantly from 9.0 ± 2.1% at baseline to 6.5 ± 0.9% at week 24, and GA decreased significantly from 24.3 ± 8.2% to 16.2 ± 3.1%. The GA/HbA1c ratio decreased significantly from 2.66 ± 0.37 at baseline to 2.47 ± 0.29 at week 24 (P<0.01), despite that the GA/HbA1c ratio reached a plateau value at week 16. The change in the GA/HbA1c ratio during 24 weeks (ΔGA/HbA1c ratio) was significantly correlated with both baseline HbA1c and GA. Moreover, the ΔGA/HbA1c ratio was significantly correlated with the change in GA during 24 weeks but not with the change in HbA1c.

Conclusions: Metformin decreased the GA/HbA1c ratio in patients with newly diagnosed type 2 diabetes. This suggests that metformin improves postprandial hyperglycaemia in patients with newly diagnosed type 2 diabetes.