Correlation between Peptide Hormones and Weight and Glucose Homeostasis among Obese and Normal Weight Eastern Mediterranean Individuals
Objective: To examine the role of peptide hormones on weight and glucose homeostasis between obese and lean Eastern Mediterranean individuals. Method: Thirty obese (OB) adults (body mass index (BMI): 38.83±3.49; age, 41.05±10.72 years) and 23 normal weight (NW) age-and gender-matched (BMI: 22.02±1.91; age 40.13±10.08 years) counterparts were recruited in this cross-sectional analysis. Obesity markers (Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WtHR), percent body fat (%BF)), fasting blood concentration of peptide hormones (pancreatic polypeptide (PYY), glucagon-like peptide 1 (GLP-1), glucagon-like peptide 2 (GLP-2) cholecystokinin (CCK), , insulin, leptin, and ghrelin,), blood glucose, and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) were assessed. The association between the peptide hormones and weight status and glucose homeostasis were tested using Independent-Samples t-test, Mann- Whitney U test, Spearman and Pearson correlation, and logistic regression. Results: OB participants showed significantly higher levels of leptin (62.54±28.76 ng/ml vs 13.92 ±8.67 ng/ml; p<0.001), PYY (82.44±51.81 pg/ml vs 57.60±31.66 pg/ml; p=0.036), GLP-1 (32.74±15.73 pM vs 24.45 ± 9.64 pM; p=0.022), insulin (20.91±10.32 µU/ml vs 8.01±2.47 µU/ml; p<0.001) and HOMA-IR (5.43±2.63 vs 1.95±0.70; p<0.001). NW participants had significantly higher levels of ghrelin (431.7±202.3 pg/ml vs 231.7±130.1 pg/ml; p<0.001); no difference was seen in CCK. GLP-1 was positively correlated with all obesity markers (except for %BF) and glucose homeostasis indicators (except for glucose). Leptin was positively correlated with all markers (except for glucose). PYY was only positively correlated with obesity markers. As for ghrelin, it was inversely correlated with all of the markers except for glucose. In the regression analysis model, leptin was associated with obesity and impaired glucose homeostasis. Conclusion: Peptide hormones were significantly different among OB and NW Eastern Mediterranean individuals. A better understanding of the pathways of body weight and food intake regulating gut and adipose tissue derived hormones will help to find new strategies to treat obesity and its consequences since the effect of some hormones remains controversial.