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 

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 Low Bone Mineral Density Prior fragility fracture Long term (>3 months) glucocorticoids Increasing age Family history of osteoporotic fracture

Signs and Symptoms of Osteoporosis 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) < T score < - 1 OsteoporosisT score < Severe osteoporosisT score < fragility fracture

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 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