title: Age-related changes in bone strength from HR-pQCT derived microarchitectural parameters with an emphasis on the role of cortical porosity.
abstract: The high resolution peripheral computed tomography (HR-pQCT) technique has seen recent developments with regard to the assessment of cortical porosity. In this study, we investigated the role of cortical porosity on bone strength in a large cohort of women. The distal radius and distal tibia were scanned by HR-pQCT. We assessed bone strength by estimating the failure load by microfinite element analysis (μFEA), with isotropic and homogeneous material properties. We built a multivariate model to predict it, using a few microarchitecture variables including cortical porosity. Among 857 Caucasian women analyzed with μFEA, we found that cortical and trabecular properties, along with the failure load, impaired slightly with advancing age in premenopausal women, the correlations with age being modest, with |rage| ranging from 0.14 to 0.38. After the onset of the menopause, those relationships with age were stronger for most parameters at both sites, with |rage| ranging from 0.10 to 0.64, notably for cortical porosity and failure load, which were markedly deteriorated with increasing age. Our multivariate model using microarchitecture parameters revealed that cortical porosity played a significant role in bone strength prediction, with semipartial r(2)=0.22 only at the tibia in postmenopausal women. In conclusion, in our large cohort of women, we observed a small decline of bone strength at the tibia before the onset of menopause. We also found an age-related increase of cortical porosity at both scanned sites in premenopausal women. In postmenopausal women, the relatively high increase of cortical porosity accounted for the decline in bone strength only at the tibia.
authors.affiliation: INSERM Research Unit 1033, Université de Lyon, Lyon, France; Scanco Medical AG, Bruttisellen, Switzerland. Electronic address: nvilayphiou@scanco.ch.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vilayphiou
authors.affiliation: INSERM Research Unit 1033, Université de Lyon, Lyon, France. Electronic address: stephanie.boutroy@inserm.fr.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Boutroy
authors.affiliation: INSERM Research Unit 1033, Université de Lyon, Lyon, France. Electronic address: elisabeth.rendu@inserm.fr.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Sornay-Rendu
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands. Electronic address: B.v.Rietbergen@tue.nl.
authors.forename: Bert
authors.initials: B
authors.lastname: Van Rietbergen
authors.affiliation: INSERM Research Unit 1033, Université de Lyon, Lyon, France. Electronic address: roland.chapurlat@inserm.fr.
authors.forename: Roland
authors.initials: R
authors.lastname: Chapurlat
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D016062:Porosity; D017698:Postmenopause; D017697:Premenopause; D011884:Radius / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D012044:Regression Analysis; D013977:Tibia / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D014057:Tomography, X-Ray Computed
keywords: Cortical porosity; Finite element analysis; High resolution peripheral quantitative computed tomography; Microarchitecture; Osteoporosis