title: Decreased circulating levels of active ghrelin are associated with increased oxidative stress in obese subjects.
abstract: OBJECTIVE
  To investigate the relationship between active ghrelin and oxidative stress in obese subjects.
  
  
  METHODS
  We measured the plasma levels of free 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha), a reliable and systemic marker of oxidative stress) and the active form of ghrelin in 17 obese and 17 normal subjects. The biologically active forms of ghrelin were measured using a commercially available radio-immunoassay kit and free 8-epi-PGF(2alpha) was measured using an enzyme immunoassay kit.
  
  
  RESULTS
  The circulating level of active ghrelin was significantly decreased (20.4 +/- 2.6 vs 40.9 +/- 3.9 fmol/ml, P < 0.01) while that of 8-epi-PGF(2alpha) was significantly increased (61.5 +/- 9.6 vs 17.3 +/- 3.4 pg/ml, P < 0.01) in obese subjects compared with normal subjects. The plasma levels of active ghrelin and 8-epi-PGF(2alpha) were significantly correlated in obese (r = -0.507, P < 0.05) and in all (r = -0.577, P < 0.01) subjects. Multivariate analysis showed that the plasma levels of active ghrelin and 8-epi-PGF(2alpha) were significantly and independently correlated in all subjects (F = 7.888, P < 0.01).
  
  
  CONCLUSIONS
  There is an inverse correlation between circulating levels of active ghrelin and oxidative stress in obesity. Low circulating levels of active ghrelin may enhance oxidative stress and the process of atherosclerosis in obese subjects.
authors.affiliation: Department of Internal Medicine, Division of Diabetology and Endocrinology, Mie University School of Medicine, Tsu, Mie, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Suematsu
authors.forename: Akira
authors.initials: A
authors.lastname: Katsuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sumida
authors.forename: Esteban C
authors.initials: EC
authors.lastname: Gabazza
authors.forename: Shuichi
authors.initials: S
authors.lastname: Murashima
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Nagako
authors.initials: N
authors.lastname: Kitagawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Akatsuka
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hori
authors.forename: Kaname
authors.initials: K
authors.lastname: Nakatani
authors.forename: Kenji
authors.initials: K
authors.lastname: Togashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yano
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Adachi
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D001823:Body Composition / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D005260:Female; D054439:Ghrelin; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D015999:Multivariate Analysis; D009765:Obesity / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology*; D036361:Peptide Hormones / Q000097:blood*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D054439:Ghrelin; D007328:Insulin; D036361:Peptide Hormones; D014280:Triglycerides; C075750:8-epi-prostaglandin F2alpha; D002784:Cholesterol; D015237:Dinoprost