Effects of Teriparatide (PTH) on Bone in Men and Women With Osteoporosis
Status:
Recruiting
Trial end date:
2022-01-01
Target enrollment:
Participant gender:
Summary
Teriparatide (PTH) 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 may decrease after 20 months of therapy. However, bone biopsies of
the pelvis done on people taking teriparatide show 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 radius and
tibia in men and women with osteoporosis who receives 24 months of teriparatide therapy.
The investigators believe that this new approach of measuring bone strength will help us
better understand the mechanisms of therapeutic efficacy of teriparatide. In addition,
measuring indices of bone strength such as the material composition (bone mineral content or
BMD) and structural properties of bone (size and shape, and microarchitecture) may provide
more data about the mechanisms of how teriparatide treatment can decrease fracture risk. In
the end, this data will benefit and improve patient care by allowing us to show patients and
their providers that whether BMD increases, decreases or stay the same, there are changes in
their bone geometric structure with teriparatide therapy that increases bone strength.