title: Bone microarchitecture is impaired in adolescent amenorrheic athletes compared with eumenorrheic athletes and nonathletic controls.
abstract: BACKGROUND
  Bone mineral density (BMD) is lower in young amenorrheic athletes (AA) compared to eumenorrheic athletes (EA) and nonathletic controls and may contribute to fracture risk during a critical time of bone accrual. Abnormal bone microarchitecture is an independent determinant of fracture risk and has not been assessed in young athletes and nonathletes.
  
  
  OBJECTIVE
  We hypothesized that bone microarchitecture is impaired in AA compared to EA and nonathletes despite weight-bearing exercise.
  
  
  METHODS
  We conducted this cross-sectional study at the Clinical Research Center of Massachusetts General Hospital.
  
  
  METHODS
  We assessed BMD and bone microarchitecture in 50 subjects [16 AA, 18 EA, and 16 nonathletes (15-21 yr old)] using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography.
  
  
  RESULTS
  Groups did not differ for chronological age, bone age, body mass index, or vitamin D levels. Lumbar BMD Z-scores were lower in AA vs. EA and nonathletes; hip and femoral neck BMD Z-scores were highest in EA. At the weight-bearing tibia, athletes had greater total area, trabecular area, and cortical perimeter than nonathletes, whereas cortical area and thickness trended lower in AA. Trabecular number was lower and trabecular separation higher in AA vs. EA and nonathletes. At the non-weight-bearing radius, trabecular density was lower in AA vs. EA and nonathletes. Later menarchal age was an important determinant of impaired microarchitecture. After controlling for covariates, subject grouping accounted for 18-24% of the variability in tibial trabecular number and separation.
  
  
  CONCLUSIONS
  In addition to low BMD, AA have impaired bone microarchitecture compared with EA and nonathletes. These are the first data to show abnormal bone microarchitecture in AA.
authors.affiliation: Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Ackerman
authors.forename: Taraneh
authors.initials: T
authors.lastname: Nazem
authors.forename: Dorota
authors.initials: D
authors.lastname: Chapko
authors.forename: Melissa
authors.initials: M
authors.lastname: Russell
authors.forename: Nara
authors.initials: N
authors.lastname: Mendes
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Taylor
authors.forename: Mary L
authors.initials: ML
authors.lastname: Bouxsein
authors.forename: Madhusmita
authors.initials: M
authors.lastname: Misra
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology; D000568:Amenorrhea / Q000000981:diagnostic imaging / Q000473:pathology*; D056352:Athletes; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007118:Immunoassay; D008598:Menstruation / Q000502:physiology*; D012044:Regression Analysis; D013977:Tibia / Q000033:anatomy & histology; D014057:Tomography, X-Ray Computed; D014807:Vitamin D / Q000097:blood; D055815:Young Adult
chemical_list: D014807:Vitamin D