The Role of the Central and the Peripheral Neuropeptides in Weight Gain and Metabolic Changes Related to Olanzapine.

Objective: This study aimed to examine the role of central and peripheral neuropeptides in olanzapine-induced weight gain and metabolic changes.

Materials And Methods: Thirty patients who would receive olanzapine treatment were evaluated at the beginning of the treatment at the 2 and 8 weeks. Weight, waist circumference, the central neuropeptides pro-opiomelanocortin (POMC) and neuropeptide Y (NPY), and the peripheral adipokine leptin and the peripheral peptide cholecystokinin (CCK) levels were measured in each control. In addition, biochemical parameters such as fasting blood glucose (FBG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total and direct bilirubin, very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol, and triglyceride (TG) were measured.

Results: There were statistically significant differences weight and waist circumference levels compared to the initial levels. As observed in previous studies in the literature, changes in biochemical parameters including AST, ALT, total and direct bilirubin, LDL, TG, total cholesterol, and HDL levels were statistically significant. Levels of the neuropeptides POMC and NPY tended to increase at early stages and decrease at later stages of the treatment, while CCK and leptin levels kept increasing throughout the treatment period. The changes in POMC and CCK levels were statistically significant.

Conclusion: The results suggest that POMC and CCK may play a role in olanzapine-related weight gain.