title: Physical activity in the post-pubertal period is associated with maintenance of pre-pubertal high bone density-- a 5-year follow-up.
abstract: OBJECTIVE
  To evaluate the association between physical activity (PA) and skeletal growth in girls during adolescence.
  
  
  METHODS
  A 5-year, observational, population-based study (Reykjavik, Iceland).
  
  
  METHODS
  Seventy-eight Caucasian girls, mean age 13.4+/-1.0 (mean+/-SD) years at baseline.
  
  
  METHODS
  Bone mineral density (BMD, g/cm2) and bone width (cm) were measured in the forearm by single-photon absorptiometry at baseline and with dual-energy X-ray absorptiometry after 3 and 5 years, when lumbar spine, femoral neck (FN) and total body were also evaluated. Half of the physically active girls were compared with the other half of less active girls.
  
  
  RESULTS
  BMD in physically active girls was higher in the forearm at both baseline (P=0.001) and after 5 years (P=0.04) in comparison with less active girls. BMD was higher for the total body (P=0.0001), spine L2-L4 (P=0.02) and FN (P=0.002) in the active girls at age 18. The accrual of forearm BMD and bone width from age 13 to 18 was no different when comparing the two groups.
  
  
  CONCLUSIONS
  Pre-pubertal PA is associated with high BMD at age 13 and continued PA is associated with maintenance of high BMD until age 18.
authors.affiliation: Department of Orthopaedics, Malmo University Hospital, Malmo, Sweden. ornolfur.valdimarsson@skane.se
authors.forename: O
authors.initials: O
authors.lastname: Valdimarsson
authors.forename: G
authors.initials: G
authors.lastname: Sigurdsson
authors.forename: L
authors.initials: L
authors.lastname: Steingrímsdóttir
authors.forename: M K
authors.initials: MK
authors.lastname: Karlsson
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior; D006801:Humans; D009043:Motor Activity; D010012:Osteogenesis; D011627:Puberty; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D