Session Information
Date: Sunday, November 8, 2015
Title: Osteoporosis and Metabolic Bone Disease - Clinical Aspects and Pathogenesis Poster
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose: The relationship between BMD T-score and fracture risk
has not been established in patients on therapy. We previously reported that
denosumab (DMAb) treatment over 8 years enabled a substantial proportion of women
with osteoporosis to achieve non-osteoporotic BMD T-scores (Ferrari, ASBMR
2014). Further improvement in T-score would only be meaningful if it were associated
with fracture reductions; thus, we investigated the relationship between total
hip BMD T-score and the incidence of nonvertebral fracture through 8 years of DMAb
therapy.
Methods: For these analyses, women received DMAb for 3 years during
the FREEDOM trial (N=3902). A large subset of these women enrolled in the
Extension and received DMAb for up to an additional 5 years, for a total of up
to 8 years of continued treatment (N=2343). A
repeated-measures model was first used to estimate each subject’s BMD T-scores
during the entire follow-up, specifically at each unique nonvertebral fracture
time among all subjects at risk at the time of each fracture. Cox’s
proportional-hazards model was then fitted with time to nonvertebral fracture
as the response and total hip BMD T-score time course as a time-dependent covariate.
Results: The incidence of nonvertebral fracture was lower with higher
total hip BMD T-score throughout a wide and clinically relevant T-score
interval (Figure). For example, total hip BMD T-scores of –2.5 and –1.5 were
associated with 1-year nonvertebral fracture incidences of about 3.0% and 2.0%,
respectively. The relationship flattened at a T-score somewhere between –2.0
and –1.0, similar to what is known to occur in untreated subjects. This inverse
relationship between total hip BMD T-score and nonvertebral fracture incidence
was maintained regardless of age or prior fracture (data not shown).
Conclusion: Higher total hip BMD T-scores during DMAb treatment
were associated with a lower incidence of nonvertebral fracture, which is
similar to the relationship previously established in treatment-naïve patients.
Improvements of similar magnitude in BMD would result in different reductions
in fracture risk depending on the baseline BMD value. Our findings highlight
the importance of BMD measurement in patients on osteoporosis treatment as a predictor
of fracture risk and support the concept that a specific T-score should be
further evaluated as a practical goal for therapy.
To cite this abstract in AMA style:
Ferrari S, Libanati C, Lin C, Adami S, Brown J, Cosman F, Czerwinski E, de Gregório L, Malouf J, Reginster JY, Daizadeh N, Wang A, Wagman R, Lewiecki E. Relationship Between Total Hip BMD T-Score and Incidence of Nonvertebral Fracture with up to 8 Years of Denosumab Treatment [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/relationship-between-total-hip-bmd-t-score-and-incidence-of-nonvertebral-fracture-with-up-to-8-years-of-denosumab-treatment/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/relationship-between-total-hip-bmd-t-score-and-incidence-of-nonvertebral-fracture-with-up-to-8-years-of-denosumab-treatment/