Osteoporosis
UBC Internal Medicine Program
Dr. Mark Fok
Dr. Maria Ashley
Definition

Osteoporosis and osteopenia are skeletal
disorders characterized by low bone mass
and microarchitectural fragility.
Bone remodelling
Incidence
1.4 million Canadians affected
 1 in 4 women over age 50 and 1 in 8
men over age 50
 Estimated cost of $1.9 billion to treat
osteoporosis and fractures in Canada
 70% of hip fractures are osteoporosis
related

 www.osteoporosis.ca
What else do you want to know?

Major Risk Factors for Osteoporosis
 Age >65
 Vertebral compression #
 Family hx of osteoporotic #
 >5 months glucocorticoid tx
 Malabsorbtion syndrome
 1 hyperparathyroidism
 Osteopenia on XR
 Hypogonadism
 Early menopause (before 45)
 Minor
Risk Factors
◦ Rheumatoid arthritis
◦ Hyperthyroidism
◦ Prolonged anticonvulsants
◦ Prolonged heparin use
◦ Body weight <57kg
◦ Low calcium intake
◦ Excess caffeine (>4 cups/day)
◦ Excess alcohol (>2 drinks/day)
◦ Smoker
Risk for Fracture


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Low Bone Mineral Density
Prior fragility fracture
Long term (>3 months) glucocorticoids
Increasing age
Family history of osteoporotic fracture
Signs and Symptoms of Osteoporosis



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Self reported height loss >3cm
Weight <51kg
Kyphosis - Self reported hump back
Grip strength <40lb
Tooth count <20
Diagnosis of Osteoporosis

Assessment bone microarchitecture –
bone biopsy

Clinical – fracture in the right context

Gold standard…
Bone Mineral Density Assessment

Dual-Energy Xray Absorptiometry (DXA)
◦ Strong correlation between mechanical bone
strength DXA measurement of BMD
◦ Strong relationship between fracture risk and
BMD measurement
Lotz JC et al. J Biomech Eng 1991
Marshall D et al. BMJ 1996
DXA



Xray tube
generates photon
beams at two
energy levels
Difference in
attenuation  BMD
determination
For comparison,
must use same
machine
Interpreting a DXA Scan ?
Interpreting the DXA

T-score:
◦ Standard deviation between a pt’s BMD and
that of a young adult reference population

Z-score:
◦ Standard deviation between a pt’s BMD and
that of an age matched population
Interpreting the DXA – WHO criteria
Normal
- 1 < T score
Low Bone Mass
(osteopenia)
Osteoporosis
- 2. 5 < T score < - 1
Severe osteoporosis
T score < - 2.5 + fragility
fracture
T score < - 2.5
DXA scan hip / L-spine
Treatment of Osteoporosis

Non-drug options

Drug options
Weight bearing exercises

Exercises that utilize your own body
weight include activities like these, but
also include simple activities like walking.
Calcium rich foods
Over the counter vitamins

1200-1500 mg
elemental calcium
per day

800 IU vitamin D
per day
Drugs – “Bisphosphonates”

Alendronate

Risedronate

Etidronate
Dosing

Once weekly dosing (70 mg q week) as
effective as daily dosing of alendronate
with similar side effect profile
Rizzoli et al. J Bone Miner Res 2002
Risedronate

Similar efficacy

Comparable to
Alendronate
Rosen et al. J Bone Miner. Res. 2005
“Selective Estrogen
Receptor Modulators”

Raloxifene

Tamoxifen
 Bind with high affinity to Estrogen Receptor and
possess tissue selective agonist / antagonist
properties  bone specific “estrogen like” action
Bone Forming (Anabolic)
Medications

Parathyroid Hormone –Teriparatide
(brand name - Forteo®).

Teriparatide, a type of parathyroid
hormone, is approved for the treatment of
osteoporosis in postmenopausal women
and in men who have very low BMD or
are at high risk for a fracture.
Estrogen therapy



Fallen out of favor
for treatment of
osteoporosis since
WHI study
Increased risk of
CHD, VT, breast CA
Should not be used
first line, except for
in women using it
for other
indications
Quick quiz 1.Are you over 65? 2.Has either of your parents
broken a bone after a minor bump or fall? 3.Have you
broken a bone after a minor bump or fall? 4.Have you taken
glucocorticoid pills (cortisone, prednisone, etc.) for more than
three months? 5.Have you lost more than 4 cm (about 1 1/2
inches) in height since age 25 (or 6 cm if you are over 60)?
6.Do you have a tendency to fall? 7.Do you have primary
hyperparathyroidism? 8.Do you have a medical condition
(such as celiac disease or Crohn's disease) that inhibits
absorption of nutrients? 9.Has a recent x-ray suggested you
have low bone density (osteopenia)?
For Women:10.Did you undergo menopause before age 45?
11.Have your periods stopped for several months or more
(other than for pregnancy or menopause)?
For Men:12.Have you ever suffered from impotence, lack of
libido or other symptoms related to low levels of
testosterone?
If you're over 50 and have answered yes to any of these
questions, Osteoporosis Canada recommends that you talk to
your doctor about having a bone mineral density (BMD) test.
Thank you