Τίτλος:
Low BMD is less predictive than reported falls for future limb fractures
in women across Europe: results from the European Prospective
Osteoporosis Study
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
We have previously shown that center- and sex-specific fall rates
explained one-third of between-center variation in upper limb fractures
across Europe. In this current analysis, our aim was to determine bow
much of the between-center variation in fractures could be attributed to
repeated falling, bone mineral density (BMD), and other risk factors in
individuals, and to compare the relative contributions of centerspecific
BMD vs. center-specific fall rates. A clinical history of fracture was
assessed prospectively in 2451 men and 2919 women aged 5080 from 20
centers participating in the European Prospective Osteoporosis Study
(EPOS) using standardized questionnaires (mean follow-up = 3 years).
Bone mineral density (BMD, femoral neck, trochanter, and/or spine) was
measured in 2103 men and 2565 women at these centers. Cox regression was
used to model the risk of incident fracture as a function of the
person-specific covariates: age, BMD, personal fracture history (PFH),
family hip fracture history (FAMHIP), time spent walking/cycling, number
of ‘all falls’ and falls not causing fracture fracture-free’) during
follow-up, alcohol consumption, and body mass index. Center effects were
modeled by inclusion of multiplicative gamma-distributed random effects,
termed center-shared frailty (CSF), with mean 1 and finite variance
theta (theta) acting on the hazard rate. The relative contributions of
center-specific fall risk and center-specific BMD on the incidence of
limb fractures were evaluated as components of CSF.
In women, the risk of any incident nonspine fracture (n = 190) increased
with age, PFH, FAMHIP, >= 1 h/day walking/cycling, and number of ‘all
falls’ during follow-up (all P < 0.074). ‘Fracture-free’ falls (P =
0.726) and femoral neck BMD did not have a significant effect at the
individual level, but there was a significant center-shared frailty
effect (theta = 0.271, P - 0.001) that was reduced by 4% after
adjusting for mean center BMD and reduced by 19% when adjusted for mean
center fall rate. Femoral trochanter BMD was a significant determinant
of lower limb fractures (n = 53, P = 0.014) and the center-shared
frailty effect was significant for upper limb fractures (theta = 0.27 1,
P = 0.011). This upper limb fracture center effect was unchanged after
adjusting for mean center BMD but was reduced by 36% after adjusting
for center mean fall rates.
In men, risk of any nonspine fracture (n = 75) increased with PFH, fall
during follow-up (P < 0.026), and with a decrease in trochanteric BMD
[RR 1.38 (1.08, 1.79) per 1 SD decrease]. There was no center effect
evident (theta = 0.081, P = 0.096).
We conclude that BMD alone cannot be validly used to discriminate
between the risk of upper limb fractures across populations without
taking account of population-specific variations in fall risk and other
factors. These variations might reflect shared environmental or possibly
genetic factors that contribute quite substantially to the risk of upper
limb fractures in women. (c) 2004 Elsevier Inc. All rights reserved.
Συγγραφείς:
Kaptoge, S
Benevolenskaya, LI
Bhalla, AK
Cannata, JB and
Boonen, S
Falch, JA
Felsenberg, D
Finn, JD
Nuti, R and
Hoszowski, K
Lorenc, R
Miazgowski, T
Jajic, I
Lyritis, G
and Masaryk, P
Naves-Diaz, M
Poor, G
Reid, DM and
Scheidt-Nave, C
Stepan, JJ
Todd, CJ
Weber, K
Woolf, AD
and Roy, DK
Lunt, M
Pye, SR
O'Neill, TW
Silman, AJ and
Reeve, J
Εκδότης:
EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC
Λέξεις-κλειδιά:
falls; prospective study; epidemiology; osteoporosis; incident limb
fractures; bone mineral density
DOI:
10.1016/j.bone.2004.11.012
