title: Determinants of age-associated changes in os calcis ultrasonic indices in elderly women: potential involvement of geriatric hyposomatotropism in bone fragility.
abstract: OBJECTIVE
  ultrasound measures a clinically relevant property of bone strength in addition to and distinct from bone mass. The aim of the present study was to examine the effects of healthy ageing on ultrasound measurements of the calcaneus.
  
  
  METHODS
  cross-sectional study.
  
  
  METHODS
  a sample of 177 community-dwelling healthy women aged 70-87 years. Exclusion criteria were diseases or medications known to affect the musculoskeletal system or the somatotrophic axis.
  
  
  METHODS
  serum levels of 1,25-dihydroxyvitamin D3 and insulin-like growth factor-I (IGF-I) were measured by radioimmunoassay, serum 25-hydroxyvitamin D3 (25(OH)D3) was determined by competitive binding assay and serum parathyroid hormone was assessed immunochemically. Isometric and isokinetic quadriceps strength were evaluated using a Cybex II system. Calcaneal ultrasound indices--broadband ultrasound attenuation (BUA) and speed of sound (SOS)--were measured with an Achilles system.
  
  
  RESULTS
  we found a significant decrease with ageing in BUA and SOS (-0.5 and -1.3% per year, respectively), suggesting a continuing loss of bone quality. Quadriceps strength, serum IGF-I and 25(OH)D3 constituted the best predictors of BUA, while IGF-I was the only parameter found to be independently associated with SOS.
  
  
  CONCLUSIONS
  these findings suggest that, among other factors, the activity of the growth hormone-IGF-I axis is of importance for skeletal integrity. Age-related bone fragility may, in part, be related to geriatric hyposomatotropism.
authors.affiliation: Arthritis and Metabolic Bone Disease Research Unit, Katholieke Universiteit Leuven, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Boonen
authors.forename: P H
authors.initials: PH
authors.lastname: Nicholson
authors.forename: G
authors.initials: G
authors.lastname: Lowet
authors.forename: X G
authors.initials: XG
authors.lastname: Cheng
authors.forename: G
authors.initials: G
authors.lastname: Verbeke
authors.forename: E
authors.initials: E
authors.lastname: Lesaffre
authors.forename: J
authors.initials: J
authors.lastname: Aerssens
authors.forename: J
authors.initials: J
authors.lastname: Dequeker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D002111:Calcaneus / Q000000981:diagnostic imaging*; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007537:Isometric Contraction / Q000502:physiology; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging; D010281:Parathyroid Hormone / Q000097:blood; D014463:Ultrasonography; D014808:Vitamin D Deficiency / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D002117:Calcitriol; D002112:Calcifediol