The effect of experimentally induced energy imbalance on fasting serum obestatin

Background: Obestatin is a recently discovered adipocytokin. Its role has been studied in the fields of obesity, diabetes mellitus, and psychogenic eating disorders. Objectives: Assessing the effect of energy imbalance on the serum obestatin level and its relation to BMI, blood glucose, insulin level, HOMA -IR and lipid profile. Design: 54 adult male Wister albino rats were utilized. They were divided into three equal groups according to their diet regimens; Group1: average caloric diet (ACD) was fed a standard chow diet (3.84 Kcal/gm); Group2: restricted caloric diet (RCD) was fed a reduced caloric diet (2.30 Kcal/gm), and Group3: High calorie diet (HCD) was fed a high fat diet (4.89 Kcal/gm). The animals were sacrificed (6 animals from each group) 10 days apart (after 10, 20, & 30 days). Results: Fasting obestatin level did not show significant changes in the ACD group at different studied time points. While, significant increases in its levels were demonstrated in the RCD group after 20 and 30 days. Inversely, it was significantly decreased after 20 and 30 days in the HCD group. Moreover, obestatin was negatively correlated with BMIs, blood glucose, serum insulin and HOMA-IR in the RCD as well as HCD groups after 20 and 30 days. Conclusion: Obestatin is involved in the regulation of energy balance .So, disturbance in serum obestatin could be used as an indicator of energy imbalance. This gives a new insight about the anticipation of obestatin agonist/s and antagonist/s as new drugs for treatment of obesity and cachexia.