The Effects of Exenatide and Metformin on Endothelial Function in Newly Diagnosed Type 2 Diabetes Mellitus Patients: A Case-Control Study

INTRODUCTION

Exenatide is a new antidiabetic glucagon-like peptide-1 receptor agonist. In addition to its hypoglycemic effect, exenatide may have a potential protective benefit on vascular endothelial function. This study attempted to compare the effects of exenatide and traditional antidiabetic drug metformin treatment on endothelial function in overweight patients with type 2 diabetes.

METHODS

Ninety overweight patients with newly diagnosed type 2 diabetes were recruited; 45 patients received exenatide (Exe) treatment and 45 patients received metformin (Met) treatment for 12 weeks. The control groups included 37 overweight and 24 non-overweight individuals. The parameters of glucose and lipid metabolism and endothelial function were measured before and after treatment. Vascular endothelial dysfunction was measured by reactive hyperemia index.

RESULTS

Newly diagnosed patients with type 2 diabetes had more serious vascular endothelial dysfunction than both overweight and normal-weight control groups. The levels of body mass index, glucose, HbA1c, homeostasis model assessment insulin resistance, and homeostasis model assessment β-cell function were improved significantly by both exenatide and metformin treatment. Both exenatide and metformin treatment can improve vascular endothelial function (Exe group: 1.67 ± 0.52 vs 1.98 ± 0.67, P < 0.05; Met group: 1.68 ± 0.29 vs 1.82 ± 0.24, P < 0.05). Exenatide treatment was no less effective than metformin in improving endothelial function (0.31 ± 0.70 vs 0.13 ± 0.24, P > 0.05).

CONCLUSIONS

Newly diagnosed patients with type 2 diabetes may have vascular endothelial dysfunction. Both exenatide and metformin treatment can improve vascular endothelial dysfunction, and exenatide was no less effective than metformin treatment.

Factors That Influence Pancreatic Beta Cell Function and Insulin Resistance in Newly Diagnosed Type 2 Diabetes Patients: A Sub-Analysis of the MARCH Trial

INTRODUCTION

The Metformin and Acarbose in Chinese as the initial Hypoglycemic treatment (MARCH) trial has demonstrated a similar efficacy in HbA1c reduction between acarbose and metformin treatments in newly diagnosed type 2 diabetes mellitus (T2DM) patients. The current sub-analysis of the MARCH trail aims to evaluate the baseline characteristics that may influence the improvement of pancreatic β-cell function and insulin resistance after acarbose therapy in Chinese patients with newly diagnosed T2DM.

METHODS

Of the 784 patients who entered the MARCH trail, 391 were assigned to the acarbose therapy group; 304 of these completed 48 weeks of follow-up of acarbose therapy. At 48 weeks, on the basis of the tertiles of change in homeostasis model assessment-beta cell function (∆HOMA-β) and homeostasis model assessment-insulin resistance (∆HOMA-IR), the subjects were divided into lowly, mediumly, and highly improved groups.

RESULTS

In the highly improved HOMA-β group, patients had higher systolic blood pressure (SBP), 2-h postprandial blood glucose (PBG), hemoglobin A1c (HbA1c), and lower high-density lipoprotein cholesterol (HDL-c), fasting serum insulin (FINS) concentration, and HOMA-IR in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between HbA1c, SBP, and highly improved ∆HOMA-β (p < 0.05), while an inverse correlation was evident between HDL-c and highly improved ∆HOMA-β (p < 0.05). The highly improved HOMA-IR group had a significantly higher body mass index (BMI), fasting blood glucose (FBG), FINS concentration, and HOMA-β in comparison to the lowly improved group (p < 0.05). A positive correlation was observed between FBG, waist circumference, and highly improved HOMA-IR (p < 0.05).

CONCLUSION

Newly diagnosed T2DM Chinese patients with lower baseline HDL-c and higher HbA1c and SBP values are more likely to achieve improvement in beta cell function whereas baseline fasting blood glucose and waist circumference were the significant factors associated with improvement in insulin resistance with acarbose therapy.

TRIAL REGISTRATION

The clinical trial registry number was ChiCTR-TRC-08000231.