The Role of Ghrelin, Neuropeptide Y and Leptin Peptides in Weight Gain after Deep Brain Stimulation for Parkinson’s Disease

Background: The exact mechanism of weight gain (WG) after deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients with idiopathic Parkinson’s disease remains unknown. Objectives: To investigate a possible involvement of ghrelin, neuropeptide Y (NPY) and leptin in WG after DBS. Methods: Twenty-three Parkinson patients were submitted for body composition measurements and blood sampling 3 days before, and 3 and 6 months after STN DBS. Peripheral concentrations of ghrelin, NPY, and leptin were determined, as well as the L-dopa equivalent daily dose. Patients were clinically evaluated using the Unified Parkinson’s Disease Rating Scale. Results: Three months after surgery, a significant WG was observed (3.09 ± 5.00 kg; p = 0.007) with no further increase at 6 months. Three months postoperatively, NPY circulating levels increased significantly (p = 0.05), while the increase of ghrelin levels reached statistical significance at 6 months (p = 0.001). WG was significantly associated with changes of ghrelin and leptin levels at 3 and 6 months, respectively. Conclusions: STN DBS seems to temporarily dysregulate the hypothalamic secretion of NPY and ghrelin. The variation of weight may be attributed to an increased production of ghrelin and leptin. A possible neuroprotective role of DBS, exerted through the increase of ghrelin levels, should be further studied.