Leptin, Neuropeptide Y and Islet Amyloid Polypeptide Levels in Obese Children

Abstract

Purpose: The aim of this study was to compare serum leptin, neuropeptide Y (NPY), and islet amyloid polypeptide (amylin) levels in obese and normal weight children, and to investigate their correlations with anthropometric parameters and metabolic bio-marker levels. Methods: Body mass index (BMI), waist and hip circumference, blood pressure (systolic/diastolic), lipid profile, fasting glucose, and serum insulin, leptin, NPY, and amylin levels were measured in 56 children (24 obese children and 32 non-obese controls). Homeostatic model assessment-insulin resistance (HOMA-IR) values were calculated and the relationships between anthropometric variables, metabolic biomarkers, and diet-regulating factors (leptin, NPY, and amylin levels) were examined. Results: BMI, hip circumference, waist circumference, and systolic and diastolic pressure were significantly higher in the obese group than in the non-obese group (p＜0.0001). Total cholesterol, triglyceride, low-density lipoprotein -cholesterol, glucose, and insulin levels were also significantly higher in the obese group (p＜0.05). On the other hand, high-density lipoprotein-cholesterol levels were higher in the non-obese group , but this was not significant. Serum leptin, NPY, and amylin levels were significantly higher in the obese group (p＜0.05). Furthermore, in the obese group, leptin levels were found to be significantly correlated with BMI (r=0.379, p=0.043), and NPY levels (r=0.377, p=0.044), and amylin levels were found to be significantly correlated with insulin levels (r=0.400, p=0.048), and HOMA-IR (r=0.459, p=0.028). Conclusion: Metabolic risk factor alterations are present in obese children, and these children show abnormalities in the diet regulatory system caused by leptin, NPY, and amylin resistance. Of particular note, amylin was found to be positively correlated with insulin resistance. (Pediatr Gastroenterol Hepatol Nutr 2012; 15: 166∼174)