Schlüsselwörter - Osteologie Kongress 2012

V 7.2 later Menarche is Associated with Reduced Bone
Strength as Assessed by FEA at Distal Tibia in Healthy 20-
Year Old and in Premenopausal Women
T. Chevalley1 , T. Chevalley1 , J.-P. Bonjour1 , B. Van Rietbergen2 , S. Ferrari1 ,
R. Rizzoli1 1Division of Bone Diseases, Geneva; 2Department of Biomedical Engineering, Eindhoven
In postmenopausal women, later menarche is a risk factor for fragility fractures,
as observed at several skeletal sites including spine, proximal femur and
forearm. We previously showed that the negative influence of later menarcheal
age (MENA) on areal and volumetric bone mineral density (BMD) in
the femoral neck and distal tibial remained unattenuated a few years before
menopause and was independent of premenopausal bone loss. We investigated
in the present study, whether the negative effects of later MENA on both
bone mineral mass and microstructure would result in reduced bone strength.
Therefore, we assessed in 320 healthy women the relation between MENA and
bone strength variables of distal tibia. These biomechanical properties including
stiffness (kN/mm), failure load (N) and apparent modulus (MPa) were
evaluated by micro-finite element analysis (µFEA) obtained using microstructural
measurements of distal tibia by high resolution peripheral quantitative
computerized tomography (HR-pQCT). 124 young adult women (YAD)
with mean age 20.4±0.6 (SD) yrs who were followed-up from age 7.9±0.5 yr,
with a prospective recording of MENA and 196 premenopausal women (PRE-
MENO) with mean age 45.9±3.7 yrs were simultaneously investigated. Both
groups were dichotomized by the median of MENA in LATER (mean age 14.3
yrs) and EARLIER (mean age 12.0 yrs). The average of MENA was not significantly
different in YAD (13.0±1.2) vs. PREMENO (13.2±1.6). At distal tibia
of YAD and PREMENO, LATER MENA was associated with a trend to lower
stiffness (P=0.078), lower failure load (P=0.098), and with a lower apparent
modulus (P=0.002). By two-way variance analysis, the effects of MENA (LAT-
ER vs EARLIER, P=0.002) and age (PREMENO vs. YAD, P 60 years living in the region Vaud will be offered OP
screening with new equipment installed in a bus. The main goal is to evaluate
the fracture risk with the combination of clinical risk factors (CRF) and informations
extracted by a single DXA: bone mineral density (BMD), vertebral
fracture assessment (VFA), and micro-architecture (MA) evaluation. MA is yet
evaluable in daily practice by the Trabecular Bone Score (TBS) measure. TBS
is a novel grey-level texture measurement reflecting bone MA based on the use
of experimental variograms of 2D projection images. TBS is very simple to obtain,
by reanalyzing a lumbar DXA-scan. TBS has proven to have diagnosis
and prognosis value, partially independent of CRF and BMD. A 55-years follow-up
is planned.
Method: The Osteo-Mobile Vaud cohort (1500 women, > 60 years, living in
the region Vaud) started in July 2010. CRF for OP, lumbar spine and hip BMD,
VFA by DXA and MA evaluation by TBS are recorded. Preliminary results are
reported.
Results: In July 31th, we evaluated 510 women: mean age 67 years, BMI 26
kg/m². 72 women had one or more fragility fractures, 39 had vertebral fracture
(VFx) grade 2/3. TBS decreases with age (-0.005 / year, p