title: Acute effects of different glycemic index diets on serum motilin, orexin and neuropeptide Y concentrations in healthy individuals.
abstract: OBJECTIVE
  To determine whether different glycemic index (GI) diets have different effects on the acute secretion of motilin, orexin and neuropeptide Y (NPY), regulators of food intake, energy homeostasis and glucose metabolism.
  
  
  METHODS
  Fifty healthy volunteers were randomly assigned to two groups and were fed an isocaloric breakfast (464 kcal) containing high GI (HGI; GI=90) or low GI (LGI; GI=47) components. Serum motilin, orexin, and NPY concentrations were measured before (0 h) and 2h after the meal.
  
  
  RESULTS
  The concentrations of motilin, orexin-A, NPY, C-peptide, and blood glucose at 0 h were similar in both groups of subjects. However, 2 h after breakfast, the serum motilin, NPY, C-peptide, and blood glucose concentrations were increased and orexin-A concentrations were decreased in both groups. The percentage changes from 0 to 2 h [(2-h value-0-h value)/baseline×100)] in motilin (27.72±2.46% vs. 20.95±2.06%, p=0.04) and orexin-A (9.15±2.06% vs. 3.49±1.67%, p=0.038) concentrations were significantly higher in the LGI group than in the HGI group. By contrast, the percentage changes in NPY (53.7±9.73% vs. 28.1±5.2%, p=0.026) and blood glucose (12.3±3.78% vs. 1.77±2.52%, p=0.025) concentrations were significantly greater in the HGI group than in the LGI group. Although C-peptide concentrations increased significantly after breakfast in both groups, the magnitude of the increase was similar (132.69±25.15% vs. 139.98±27.29%, p=0.845). Motilin and NPY concentrations were moderately positive correlated (r=0.410, p=0.042), while orexin-A and NPY concentrations were negatively correlated (r=-0.429, p=0.033) at 2h in the LGI group.
  
  
  CONCLUSIONS
  A breakfast with a LGI reduced the secretion of orexin-A but significantly stimulated motilin secretion, without marked effects on the secretion of NPY. Therefore, consumption of a LGI diet may help to regulate food intake and energy expenditure in healthy individuals based on the changes in these hormones.
authors.affiliation: Institute and Department of Endocrinology and Metabolism, Shanghai Ninth People's Hospital Affiliated to Shanghai JiaoTong University School of Medicine, Shanghai, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.forename: Fang-zhen
authors.initials: FZ
authors.lastname: Xia
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Hua-ling
authors.initials: HL
authors.lastname: Zhai
authors.forename: Mei-fang
authors.initials: MF
authors.lastname: Zhang
authors.forename: Hui-xin
authors.initials: HX
authors.lastname: Zhang
authors.forename: Yan-xiang
authors.initials: YX
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Gu
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Ma
authors.forename: Ying-li
authors.initials: YL
authors.lastname: Lu
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D004032:Diet; D004435:Eating / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D038321:Glycemic Index / Q000502:physiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D050417:Insulin-Secreting Cells / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009037:Motilin / Q000097:blood*; D009478:Neuropeptide Y / Q000097:blood*; D009479:Neuropeptides / Q000097:blood*; D000068797:Orexins; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin; D047908:Intracellular Signaling Peptides and Proteins; D009037:Motilin; D009478:Neuropeptide Y; D009479:Neuropeptides; D000068797:Orexins; C000596229:HCRT protein, human