title: Hip structural analysis in adolescent and young adult oligoamenorrheic and eumenorrheic athletes and nonathletes.
abstract: BACKGROUND
  Stress fractures are common in endurance athletes. Whereas studies have described distal tibia bone structure in athletes, there are few data regarding hip geometric parameters. Hip structural analysis (HSA) using dual-energy x-ray absorptiometry is a validated technique to assess hip bone structure.
  
  
  OBJECTIVE
  The purpose of this study was to compare hip geometry in young oligoamenorrheic athletes (AAs), eumenorrheic athletes (EAs), and nonathletes using HSA. We hypothesized that AAs would have impaired bone structure compared with that of EAs.
  
  
  METHODS
  This was a cross-sectional study.
  
  
  METHODS
  The setting was a clinical research center.
  
  
  METHODS
  We enrolled 55 AAs, 24 EAs, and 23 nonathletes of normal weight who were 14 to 22 years old. Athletes ran ≥20 miles/wk or were engaged in weight-bearing sports for ≥4 hours/wk.
  
  
  METHODS
  Dual-energy x-ray absorptiometry was used for HSA and hip areal bone mineral density (aBMD).
  
  
  RESULTS
  Hip aBMD Z-scores were lower in AAs and in nonathletes than in EAs (P = .002). A larger proportion of AAs than EAs and nonathletes had hip Z-scores <-1 (30.9, 4.2, 17.4%, P = .01). At the narrow neck, trochanteric region, and femoral shaft, subperiosteal width, cross-sectional moment of inertia, and section modulus were higher in EAs than in nonathletes; values in AAs did not differ from those of nonathletes. Cross-sectional area was lower in AAs and in nonathletes than in EAs. Groups did not differ for cortical thickness or buckling ratio. Group differences were lost after adjustment for lean mass but not aBMD.
  
  
  CONCLUSIONS
  In an eugonadal state, athletic activity confers benefits for hip structure independent of aBMD. This advantage is lost in AAs, who do not differ from nonathletes for most parameters and fare worse than EAs for cross-sectional area.
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Ackerman
authors.forename: Lisa
authors.initials: L
authors.lastname: Pierce
authors.forename: Gabriela
authors.initials: G
authors.lastname: Guereca
authors.forename: Meghan
authors.initials: M
authors.lastname: Slattery
authors.forename: Hang
authors.initials: H
authors.lastname: Lee
authors.forename: Mark
authors.initials: M
authors.lastname: Goldstein
authors.forename: Madhusmita
authors.initials: M
authors.lastname: Misra
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000365:Age Determination by Skeleton; D000568:Amenorrhea / Q000000981:diagnostic imaging / Q000473:pathology*; D056352:Athletes; D015519:Bone Density / Q000502:physiology; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006615:Hip / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology; D055815:Young Adult