The effect of orlistat and weight loss diet on plasma ghrelin and obestatin.

Background: The objective of this study was to evaluate the effect of weight loss with hypocaloric diet and orlistat treatment in addition to hypocaloric diet on gut-derived hormones ghrelin and obestatin.

Materials And Methods: A total of 52, euglycemic and euthyroid, obese female patients were involved in the study. The patients were assigned to two groups: Group 1 ( = 26) received hypocaloric diet alone and Group 2 ( = 26) received orlistat in addition to hypocaloric diet for 12 weeks. Anthropometric measurements, serum lipid, insulin levels, and obestatin and ghrelin values were assessed at the beginning of the study and after 12 weeks of therapy.

Results: Baseline clinical characteristics and laboratory parameters including serum ghrelin and obestatin concentrations and ghrelin/obestatin ratio were similar between the two groups. After 12 weeks, mean change in BMI, fat mass, and fat-free mass (FFM) were -1.97 ± 1.56 kg/m ( = 0.003), -2.63% ±2.11% ( = 0.003), and -1.06 ± 0.82 kg ( = 0.003), respectively, in Group 1. In Group 2, mean change in BMI was -2.11 ± 1.24 kg/m ( = 0.001), fat mass was -3.09% ±2.28% ( = 0.002), and FFM was -1.26 ± 0.54 kg ( = 0.001). However, fasting glucose, lipid, and insulin levels did not change in Group 1. Furthermore, except serum high-density lipoprotein cholesterol and triglyceride levels, no significant change was observed in Group 2. Although serum ghrelin and obestatin concentrations increased significantly in both groups (Group 1: pGhrelin: 0.047, pobestatin: 0.001 and Group 2: pGhrelin: 0.028, pobestatin: 0.006), ghrelin/obestatin ratio did not change significantly. When the changes in anthropometric assessments and laboratory parameters were compared, no significant difference was observed between the two groups. Furthermore, no correlation was observed between ghrelin or obestatin and any other hormonal and metabolic parameters.

Conclusion: Weight loss with diet and diet plus orlistat is both associated with increased ghrelin and obestatin concentrations.