Conclusion

Novel therapies based on the physiologic and pharmacologic glucoregulatory effects of incretin hormones, mimicking the effects of GLP-1 (e.g. incretin mimetics), or increasing endogenous incretin concentrations (e.g. DPP-IV inhibitors), provide new options for the treatment of type 2 diabetes. The unique ability of incretin mimetics to enhance glucose-dependent insulin secretion, slow gastric emptying, suppress glucagon secretion, decrease food intake, and even cause body weight loss (e.g. exenatide), provides new therapeutic choices for patients with type 2 diabetes. Furthermore, since these compounds have been shown to improve β-cell mass in animal studies and function in clinical studies, these compounds may potentially be able to alter the natural progression of diabetes, and associated complications.

Table 2. Summary of Randomized clinical trials with Exenatide

Authors

Number of Patients

Duration of Treatment

Treatment groups

Primary Endpoint

Summary of Results

Fineman et al.84

109

4 weeks

Exenatide 0.08 mcg/kg bid or tid vs. placebo

A1C

Significant reduction in A1C with exenatide treatment. Most common side effects were nausea and hypoglycaemia.

Poon et al.85

156

4 weeks

Exenatide 2.5, 5, 7.5 and 10 mcg bid vs. placebo

A1C

Significant, dose-dependent, reduction in A1C with exenatide treatment. Most common side effect was dose dependent nausea.

Buse et al.79

377

30 weeks

Exenatide 5 and 10 mcg SC (bid) vs. placebo in sulfonylurea treated patients

A1C

Significant dose dependent reduction in A1C and body weight with exenatide treatment. Nausea and hypoglycaemia were the most common side effect.

De Fronzo et al.80

336

30 weeks

Exenatide 5 and 10 mcg SC (bid) vs. placebo in metformin treated patients

A1C

Significant dose dependent reduction in A1C and body weight with exenatide treatment. Nausea was the most common side effect. No increase in risk of hypoglycaemia when exenatide added with metformin.

Kendall et al.81

733

30 weeks

Exenatide 5 and 10 mcg SC (bid) vs. placebo in metformin and sulfonylurea treated patients

A1C

Significant dose dependent reduction in A1C and body weight with exenatide treatment. Nausea and hypoglycaemia were the most common side effect.

Table 3. Summary of Randomized clinical trials with Liraglutide

Authors

Number of Patients

Duration of Treatment

Treatment groups

Primary Endpoint

Summary of Results

Degn et al.87

13

1 week

Liraglutide 6 mcg/kg SC vs. placebo

24 h plasma glucose

Significant reduction of mean plasma glucose.

Madsbad et al.91

193

12 weeks

Liraglutide 0.045, 0.225, 0.45, 0.6 and 0.75 mg qd vs. placebo

A1C

Significant reduction in A1C with no weight gain. Dose dependent nausea was the most frequent adverse event.

Harder et al.89

33

8 weeks

Liraglutide 0.6 mg SC qd vs. placebo

A1C, glucose, body composition

Significant reduction in A1C. No difference in body weight, body composition or 24-h energy expenditure. Nausea and diarrhea were the most common adverse events.