title: Quantitative ultrasound variables of the heel in Finnish men aged 18-20 yr: predictors, relationship to bone mineral content, and changes during military service.
abstract: BACKGROUND
  Determinants of BUA and SOS and their changes during military service-associated physical training were studied in 196 army recruits and 50 control men, aged 18-20 years.
  
  
  METHODS
  Heel ultrasound measurement, DXA, muscle strength test, Cooper's running test and genetic analyses were performed. Lifestyle factors were recorded. Sex steroids and bone turnover markers were determined. Heel ultrasound was repeated after six months.
  
  
  RESULTS
  Exercise was the most significant determinant of both BUA (p<0.0001) and SOS (p<0.0001). There were 10% and 1.3% differences in BUA (p=0.006) and SOS (p=0.0001), respectively, between men belonging to the lowest and highest quartiles of exercise index. Weight associated with BUA (p=0.005) and height with SOS (p=0.03). BUA and SOS correlated with BMC and BMD (p<0.0001) but explained only up to 21% of their variance. Over six months SOS increased more in recruits than in control men (p=0.0043), the increase being higher, the lower muscle strength at baseline (r =-0.27, p=0.0028).
  
  
  CONCLUSIONS
  Exercise is the most important determinant of ultrasonographic variables in men, aged 18-20 years. Physical loading during military training increases SOS.
authors.affiliation: Division of Endocrinology, Department of Medicine, Helsinki University Central Hospital, FI-00029 Helsinki, HUS, Finland. matti.valimaki@hus.fi
authors.forename: V-V
authors.initials: VV
authors.lastname: Välimäki
authors.forename: E
authors.initials: E
authors.lastname: Löyttyniemi
authors.forename: M J
authors.initials: MJ
authors.lastname: Välimäki
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000503:physiopathology; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology; D005269:Femur / Q000502:physiology; D005387:Finland / Q000453:epidemiology; D006365:Heel / Q000000981:diagnostic imaging* / Q000502:physiology; D006615:Hip; D006801:Humans; D008019:Life Style; D008159:Lumbar Vertebrae / Q000502:physiology; D008297:Male; D008889:Military Personnel; D053580:Muscle Strength / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology; D010806:Physical Education and Training; D011110:Polymorphism, Genetic; D014463:Ultrasonography
chemical_list: D015415:Biomarkers