Results
Effect of metformin on blood biochemical analysis
After 2 weeks of administration, FBG were significantly decreased in metformin group compared with diabetic control group, and the FBG levels were stable within the following 5 weeks (Fig. 1). In the OGTT test, KKAy mice treated with metformin showed decrease of blood glucose levels at 30 and 60 min compared with the control KKAy mice (Fig. 2A). After 5 weeks of metformin treatment, reduction of fasting insulin was previously observed in metformin group mice, when compared with control group mice (Fig. 2C). These results demonstrated that metformin improved glucose tolerance and insulin resistance in KKAy mice, which was confirmed by decrease of HOMA-IR (Fig. 2D). At the same time, the serum TG (Fig. 3B) and LDL-C (Fig. 3C) concentrations were significantly decreased in KKAy mice treated with metformin, compared with diabetic control mice (p < 0.05).