title: Acylated ghrelin and leptin in adolescent athletes with amenorrhea, eumenorrheic athletes and controls: a cross-sectional study.
abstract: OBJECTIVE
  Neuroendocrine factors may predict which athletes develop amenorrhea and which athletes remain eugonadal. Specifically, ghrelin and leptin have been implicated in regulation of GnRH secretion, with ghrelin having inhibitory and leptin, facilitatory effects. We hypothesized that adolescent athletes with amenorrhea (AA) would have higher ghrelin and lower leptin levels than eumenorrheic athletes (EA) and would predict levels of gonadal steroids.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  We enrolled 58 girls, 21 AA, 19 EA and 18 nonathletic controls 12-18 years old. Fasting blood was drawn for active ghrelin, leptin, E(2) and testosterone. Athletes were > 85% of ideal body weight for age based on body mass index (BMI).
  
  
  RESULTS
  AA girls had lower BMI than EA and controls (P = 0.003). Log ghrelin was higher in AA than in EA and controls (P < 0.0001), and remained higher after controlling for BMI Z-scores. Leptin was lower in AA than in the other groups (P < 0.0001), however, the differences did not persist after controlling for BMI Z-scores. Testosterone was lower in AA than in EA and controls (P = 0.002) and log E(2) trended lower in AA (P = 0.07). We observed inverse associations of log active ghrelin with testosterone (P = 0.01), and positive associations of leptin with testosterone and log E(2) (P = 0.02 and 0.009).
  
  
  CONCLUSIONS
  Higher ghrelin levels, even after controlling for BMI, and lower leptin in AA compared with EA and controls, and their inverse and positive associations, respectively, with gonadal steroids suggest endocrine perturbations that may explain why hypogonadism occurs in some but not all athletes.
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Karla
authors.initials: K
authors.lastname: Christo
authors.forename: Jennalee
authors.initials: J
authors.lastname: Cord
authors.forename: Nara
authors.initials: N
authors.lastname: Mendes
authors.forename: Karen K
authors.initials: KK
authors.lastname: Miller
authors.forename: Mark A
authors.initials: MA
authors.lastname: Goldstein
authors.forename: Anne
authors.initials: A
authors.lastname: Klibanski
authors.forename: Madhusmita
authors.initials: M
authors.lastname: Misra
mesh_terms: D000215:Acylation; D000293:Adolescent; D000568:Amenorrhea / Q000097:blood*; D001823:Body Composition / Q000502:physiology; D016022:Case-Control Studies; D002648:Child; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood; D005260:Female; D054439:Ghrelin / Q000097:blood* / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000097:blood; D006062:Gonadotropins / Q000097:blood; D006801:Humans; D020738:Leptin / Q000097:blood* / Q000378:metabolism; D046468:Sexual Development / Q000502:physiology; D013177:Sports / Q000502:physiology
chemical_list: D054439:Ghrelin; D012739:Gonadal Steroid Hormones; D006062:Gonadotropins; D020738:Leptin; D004958:Estradiol