Exenatide treatment causes suppression of serum fasting ghrelin levels in patients with type 2 diabetes mellitus

Aim: In the present study, we investigated the long-term effects of exenatide treatment on serum fasting ghrelin levels in patients with type 2 diabetes mellitus. Methods: Type 2 diabetic patients, who were using metformin with and without the other antihyperglycemic drugs on a stable dose for at least 3 months, were enrolled in the study. BMI>35 kg/m² and HbA1c>7.0% were the additional inclusion criteria. Oral antihyperglycemic drugs, other than metformin, were stopped, and metformin treatment was continued at 2000 mg per day. Exenatide treatment was initiated at 5 µg per dose subcutaneously (sc) twice daily, and after one month, the dose of exenatide was increased to 10 µg twice daily. Changes in anthropometric variables, glycemic control, lipid parameters and total ghrelin levels were evaluated at baseline and following 12 weeks of treatment. Results: Thirty-eight patients (male/female = 7/31) entered the study. The mean age of patients was 50.5 ± 8.8 years with a mean diabetes duration of 8.5 ± 4.9 years. The mean BMI was 41.6 ± 6.3 kg/m2 and the mean HbA1c of patients was 8.9 ± 1.4%. The mean change in the weight of patients was -5.6 kg and the percentage change in weight was -5.2 ± 3.7% following 12 weeks of treatment. BMI, fasting plasma glucose and HbA1c levels of patients were decreased significantly (P < 0.001 and P < 0.001; respectively), while there was no change in lipid parameters. Serum fasting ghrelin levels were significantly suppressed following 12 weeks of exenatide treatment compared with baseline values (328.4 ± 166.8 vs 245.3 ± 164.8 pg/mL) (P = 0.024). Conclusion: These results suggest that the effects of exenatide on weight loss may be related with the suppression of serum fasting ghrelin levels, which is an orexigenic peptide.