title: Fasting ghrelin is related to skeletal muscle mass in healthy adults.
abstract: OBJECTIVE
  The determinants of plasma ghrelin concentrations including the effects of aging, gender, and body composition, are unclear. Appetite and energy intake decrease with advancing age, and there is a corresponding decline in total body lean tissue, and an increase in fat mass.
  
  
  METHODS
  We measured fasting plasma ghrelin and insulin concentrations in 52 healthy subjects aged 22-82 years, and assessed body composition by dual energy X-ray absorptiometry. Energy intake was estimated from diet diaries.
  
  
  RESULTS
  Fasting ghrelin concentrations were not significantly correlated with age and energy intake (R = 0.07, P = 0.62; and R = -0.14, P = 0.34 respectively) on univariate regression analysis, and ghrelin concentrations were higher in females than males (2886.8 +/- 182.1 pg/ml vs 2082.5 +/- 121.2 pg/ml; P = 0.001). Ghrelin was inversely related to body mass index (R = -0.328, P = 0.018), fat-free body mass (R = -0.428, P = 0.002), and total skeletal muscle mass (R = -0.439, P = 0.001), but not related to body fat mass (R = 0.177, P = 0.208). On multiple regression analysis, total skeletal muscle mass (corrected for height) was the only significant negative predictor (P < 0.0001) of fasting ghrelin concentrations.
  
  
  CONCLUSIONS
  In conclusion, in healthy adults, plasma ghrelin concentrations are not significantly influenced by age or energy intake per se, but relate to skeletal muscle mass.
authors.affiliation: University of Adelaide Discipline of Medicine, Royal Adelaide Hospital, Adelaide, Australia. kamilia.tai@alumni.adelaide.edu.au
authors.forename: Kamilia
authors.initials: K
authors.lastname: Tai
authors.forename: Renuka
authors.initials: R
authors.lastname: Visvanathan
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Hammond
authors.forename: Judith M
authors.initials: JM
authors.lastname: Wishart
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
authors.forename: Ian M
authors.initials: IM
authors.lastname: Chapman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D002149:Energy Intake; D005215:Fasting; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D012044:Regression Analysis; D012727:Sex Characteristics
chemical_list: D054439:Ghrelin