title: Apelin, orexin-A and leptin plasma levels in morbid obesity and effect of gastric banding.
abstract: Maintenance of human energy homeostasis is regulated by a complex network. Peptides secreted from the gastrointestinal tract (GI) are signaling to the brain and other organs initiating or terminating food intake and energy expenditure. In the present study we investigated basal plasma levels of apelin, orexin-A, and leptin in morbid obese patients. In addition, we measured in a subgroup of these patients in the same individual orexin-A and leptin plasma levels one year after gastric banding surgery.
  
  
  METHODS
  Basal plasma values were determined in obese patients (BMI=48+/-1 kg/m2n=32) after an overnight fast and compared to healthy, normal weighted (BMI=22+/-2 kg/m2n=12) controls. In addition, blood samples were collected in a subgroup of patients (BMI=48+/-1 kg/m2n=8) the day before surgery and 1 year after the operation. Apelin, orexin-A, and leptin levels were analysed using ELISAs.
  
  
  RESULTS
  One year after the operation obese patients significantly lost weight (from 48+/-2 kg/m2 to 39+/-2 kg/m2; p<0,001). Apelin, orexin-A and leptin levels in obese patients were significantly higher compared to control individuals (736+/-50 pg/ml vs. 174+/-14 pg/ml, p<0.0001; 75.3+/-24.1 pg/ml vs. 0.8+/-0.4 pg/ml, p<0.0001; 79.0+/-2.4 ng/ml vs. 5.8+/-0.8 ng/ml, p<0.0001, respectively). Apelin and leptin plasma concentrations also correlated significantly with BMI (r=0.769, p<0.0001; r=0.778; p<0.0001, respectively), while orexin-A correlation was rather weak (r=0.335, p<0.03). No difference between pre- and post-operative orexin-A levels was observed, while leptin plasma levels significantly decreased from 45.1+/-5.4 ng/ml to 27.3+/-6.0 ng/ml (p=0.015).
  
  
  CONCLUSIONS
  Apelin, orexin-A, and leptin plasma levels correlated positively with the BMI. One year after gastric banding with significant loss in BMI basal plasma levels of leptin decreased, while orexin-A remained unchanged.
authors.affiliation: Department of Biotechnology/Molecular Medicine, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, 70211 Kuopio, Finland.
authors.forename: M V
authors.initials: MV
authors.lastname: Heinonen
authors.forename: A K
authors.initials: AK
authors.lastname: Purhonen
authors.forename: P
authors.initials: P
authors.lastname: Miettinen
authors.forename: M
authors.initials: M
authors.lastname: Pääkkönen
authors.forename: E
authors.initials: E
authors.lastname: Pirinen
authors.forename: E
authors.initials: E
authors.lastname: Alhava
authors.forename: K
authors.initials: K
authors.lastname: Akerman
authors.forename: K H
authors.initials: KH
authors.lastname: Herzig
mesh_terms: D000328:Adult; D000073861:Apelin; D015992:Body Mass Index; D002352:Carrier Proteins / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000378:metabolism; D015391:Gastroplasty; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins / Q000097:blood*; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009479:Neuropeptides / Q000097:blood*; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery*; D000068797:Orexins; D013997:Time Factors; D015431:Weight Loss
chemical_list: C115436:APLN protein, human; D000073861:Apelin; D002352:Carrier Proteins; C000596229:HCRT protein, human; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; D020738:Leptin; D009479:Neuropeptides; D000068797:Orexins