title: Patterns of physical activity and ultrasound attenuation by heel bone among Norfolk cohort of European Prospective Investigation of Cancer (EPIC Norfolk): population based study.
abstract: OBJECTIVE
  To study associations between patterns of physical activity and ultrasound attenuation by the heel bone in men and women.
  
  
  METHODS
  Cross sectional, population based study.
  
  
  METHODS
  Norfolk.
  
  
  METHODS
  2296 men and 2914 women aged 45-74 registered with general practices participating in European Prospective Investigation into Cancer (EPIC Norfolk).
  
  
  RESULTS
  Self reported time spent in high impact physical activity was strongly and positively associated with ultrasound attenuation by the heel bone, independently of age, weight, and other confounding factors. Men who reported participating in >/=2 hours/week of high impact activity had 8.44 dB/MHz (95% confidence interval 4.49 to 12.40) or 9.5%, higher ultrasound attenuation than men who reported no activity of this type. In women, the difference in ultrasound attenuation between those reporting any high impact activity and those reporting none was 2.41 dB/MHz (0.45 to 4.37) or 3.4% higher. In women this effect was similar in size to that of an age difference of four years. Moderate impact activity had no effect. However, climbing stairs was strongly independently associated with ultrasound attenuation in women (0.64 dB/MHz (0.19 to 1.09) for each additional five flights of stairs). There was a significant negative association in women between time spent watching television or video and heel bone ultrasound attenuation, which decreased by 0.08 dB/MHz (0.02 to 0.14) for each additional hour of viewing a week.
  
  
  CONCLUSIONS
  High impact physical activity is independently associated with ultrasound attenuation by the heel bone in men and women. As low ultrasound attenuation has been shown to predict increased risk of hip fracture, interventions to promote participation in high impact activities may help preserve bone density and reduce the risk of fracture. However, in older people such interventions may be inappropriate as they could increase the likelihood of falls.
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, Institute of Public Health, Cambridge CB2 2SR, UK.
authors.forename: R W
authors.initials: RW
authors.lastname: Jakes
authors.forename: K
authors.initials: K
authors.lastname: Khaw
authors.forename: N E
authors.initials: NE
authors.lastname: Day
authors.forename: S
authors.initials: S
authors.lastname: Bingham
authors.forename: A
authors.initials: A
authors.lastname: Welch
authors.forename: S
authors.initials: S
authors.lastname: Oakes
authors.forename: R
authors.initials: R
authors.lastname: Luben
authors.forename: N
authors.initials: N
authors.lastname: Dalzell
authors.forename: J
authors.initials: J
authors.lastname: Reeve
authors.forename: N J
authors.initials: NJ
authors.lastname: Wareham
mesh_terms: D000367:Age Factors; D000368:Aged; D015519:Bone Density; D002111:Calcaneus / Q000000981:diagnostic imaging* / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006620:Hip Fractures / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology*; D012307:Risk Factors; D014463:Ultrasonography