Plasma orexin and ghrelin response to the oral glucose tolerance test in obese women

INTRODUCTION: The aim of the present study was to examine the response of plasma orexin and ghrelin to the oral glucose tolerance test (OGTT) in obese women without additional disease. MATERIAL AND METHODS: The study group comprised 15 obese women aged 30.4+/-9.7 years of mean BMI 34.7+/-3.8 kg/m(2). The measurements were performed after an overnight fast and 30, 60 and 120 minutes after the oral administration of 75 grams of glucose. Serum concentrations of ghrelin and orexin A were measured by an enzyme-linked immunosorbent assay (ELISA) kit. Serum concentrations of insulin were measured by radioimmunoassay (RIA). Plasma glucose was determined by an enzymatic procedure. Body composition was determined by impedance analysis using Bodystat. RESULTS: We observed no significant differences between serum concentrations of ghrelin and orexin during OGTT. No correlations were found between serum ghrelin and orexin concentrations and serum insulin and glucose concentrations in any of the measurements. CONCLUSION: Oral glucose administration did not change serum concentrations of ghrelin and orexin A in obese women without additional disease.