Teriparatide (PTH) and Bone Strength in Postmenopausal Women
Status:
Active, not recruiting
Trial end date:
2023-01-01
Target enrollment:
Participant gender:
Summary
This study will investigate the effects on bone quality of a medication (Teriparatide) used
to treat people with severe osteoporosis. Teriparatide is the only bone formation therapy
that has been approved for the treatment of postmenopausal osteoporosis in Canada.
Osteoporosis is currently diagnosed using a bone mineral density (BMD) scan, which measures
the amount of mineral (calcium etc) in bones (the higher the amount of mineral, the lower the
fracture risk). Although BMD is linked to bone strength and is used to measure fracture risk,
it does not give information on bone structure (called bone geometry) which can also tell us
a great deal about fracture risks. Clinical trials have shown that teriparatide increases BMD
at the lumbar spine and total hip, while BMD at the forearm decreases after 20 months of
therapy. Whether this decrease of BMD at the forearm suggests a higher risk of wrist fracture
or a change in bone structure is unclear. Bone biopsies of the pelvis done on people taking
teriparatide shows improvement of bone geometry (ie bone thickness and increased trabeculae
(small interconnecting rods of bone), suggesting that a change in bone geometry at the wrist
may be occurring as well. Currently, there is a new technology, high resolution pQCT
(HR-pQCT) that can assess bone geometry without a biopsy. Since bone strength is affected
both by BMD and bone structure (as well as other material properties), our group is
interested in examining changes in bone geometry at the forearm (a non-weight bearing site)
and ankle (a weight bearing site) in postmenopausal women with osteoporosis who receive 24
months of teriparatide therapy. The investigators believe that this new approach of measuring
bone strength will help us better understand whether teriparatide has different effects at
different bone sites.