Differences in the levels of the appetite peptides ghrelin, peptide tyrosine tyrosine, and glucagon-like peptide-1 between obesity classes and lean controls

Objective: This study was designed to compare basal concentrations of the gastrointestinal appetite modulators ghrelin, peptide tyrosine tyrosine (PYY), and glucagon-like peptide 1 (GLP-1) between obesity classes and obesity classes and controls. Methods: The study included 49 healthy controls with body mass index (BMI) between 18.5 and 29.9 kg/m(2) and 62 individuals with obesity with BMI >= 30 kg/m(2). Basal ghrelin, PYY, and GLP-1 concentrations of the samples were analyzed by an enzyme-linked immunosorbent assay commercial kit (SunRed Human). Other biochemical parameters were measured by a clinical chemistry autoanalyzer (Beckman Coulter AU 5800) in the biochemistry laboratory. Results: Compared with the control group, ghrelin, PYY, and GLP-1 levels were significantly lower in the obese group (P < .05). The PYY concentration was significantly different between obese groups (P < .05). The PYY and GLP-1 levels were significantly different between obesity class I and obesity class III. In addition, ghrelin levels were significantly different between obesity class II and obesity class III. Correlation analysis revealed a negative correlation between BMI and serum ghrelin, GLP-1, and PYY concentrations. Conclusion: Low basal ghrelin, GLP-1, and PYY hormones in the obese group compared with the control group indicate impaired appetite regulation in this population. The significant difference in PYY levels between obese groups was associated with increasing obesity grade.