4 - Osteoporosis

Question 1

Describe osteoporosis. Define bone strength and fragility fracture

Answer 1

• Generalized skeletal disease characterized by compromised bone strength predisposing a person to increased risk of fracture
• Bone strength = bone mineral content (often measured by BMD) + bone quality (reflecting microarchitectural structure)
• Fragility fracture – occurs spontaneously or from minor trauma (falling from a standing height or less)

Question 2

Goals of therapy for osteoporosis

Answer 2

1. Reduce future risk of fractures
   - - Major = hip and vertebral fractures
   - - Hairline fractures don’t really affect people enough to go to the Dr. but could be seen on an X-ray
   - - Clinical vertebral = causes pain and seen on an X-ray
   - - Major osteoporotic = spine, forearm, shoulder, hip
2. Prevent negative outcomes as a result of fractures (disability, loss of independence, chronic pain, hospitalizations, death)

Question 3

Describe the clinical assessment for osteoporosis

Answer 3

1. Identify risk factors prompting assessment for osteoporosis (BMD testing)
2. Physical exam – measure height annually (> 6 cm loss since peak height or > 2 cm w/in past year)
3. Fall risk assessment

Question 4

What are some risk factors for older adults (50 years and older) prompting assessment for osteoporosis?

Answer 4

• Fragility fracture after age 40
• Prolonged use of glucocorticoids
• Parental hip fracture
• Vertebral fracture or osteopenia identified on radiography

Question 5

What are some risk factors for younger adults (< 50 y/o) prompting assessment for osteoporosis?

Answer 5

• Fragility fracture
• Prolonged use of glucocorticoids (prednisone 7.5 mg/day or more for 3 months or more in past year)
• Hypogonadism or premature menopause (age < 45 y/o)
• Malabsorption syndrome
• Primary hyperparathyroidism

Question 6

Drugs associated w/ osteoporosis

Answer 6

• Immunosuppressants
• PPIs
• EtOH
• Antacid (aluminum)
• Canagliflozin
• Heparin > 30 d
• Lithium
• SSRIs
• Thiazolidinediones
• Vitamin A

Question 7

Fall risk factors

Answer 7

• Muscle weakness
• Previous falls
• Impaired visual acuity
• Poor balance/ gait
• Disability
• Advanced age
• Postural hypotension
• Fear of falling
• Medications (diuretics, CNS depressants)
• Environmental factors
• Chronic conditions (arthritis, stroke, incontinence, DM, PD, dementia)

Question 8

When to treat osteoporosis

Answer 8

Depends on:

• Px risk of fracture (low < 10% = pharmacotherapy no likely benefit; moderate 10-20% = pharmacotherapy considered; high > 20% or hx of fragility fracture = pharmacotherapy recommended)
• Efficacy, safety, cost considerations of therapy
• Px goals

Question 9

Pharmacotherapy options for osteoporosis

Answer 9

• Bisphosphonates (alendronate, risedronate) – 1st line for established osteoporosis & corticosteroid-induced osteoporosis
• Denosumab SQ q6months – 1st line for established osteoporosis
• Raloxifene – decreases vertebral #s in menopausal women
• Estrogen +/- progesterone – consider for osteoporosis prevention in early post-menopause if sx of estrogen deficiency
• Teriparatide – consider for high-risk osteoporosis & corticosteroid-induced osteoporosis w/ prior fragility & low BMD
• Calcitonin – not recommended; useful for pain from acute vertebral compression
• Efficacy similar for bisphosphonates, denosumab, & estrogen (effective for vertebral, hip, & non-vertebral fractures)

Question 10

Adverse effects of bisphosphonates

Answer 10

• “Common” = GI (abdominal pain, dyspepsia, reflux, diarrhea)
• “Rare” = ONJ
• Pt should be able to swallow the capsule & stay upright for at least 30 min; should be taken 30 min before breakfast

Question 11

Adverse effects of denosumab

Answer 11

Rash, MSK pain, decreased calcium

Question 12

Adverse effects of raloxifene

Answer 12

• 5-15% flushing
• Leg cramps
• Flu-like sx

Question 13

Adverse effects of teriparatide

Answer 13

Nausea, dizziness, leg cramps

Question 14

Describe ONJ

Answer 14

• Area of exposed alveolar bone (mandible or maxilla) that doesn’t heal after 8 weeks
• Risk is higher in high-dose bisphosphonates for bone metastases, glucocorticoid use, diabetes, poor dental hygiene

Question 15

Describe atypical fractures

Answer 15

• Appear to develop as femur stress fractures
• May present as new thigh pain
• Most commonly associated w/ increased duration of use, especially > 5 years

Question 16

Monitoring for osteoporosis

Answer 16

• Recommendation was every 1-3 years, but no evidence for that claim
• Goal is to prevent fractures; studying BMD frequently is costly & yearly is unnecessary
• BMD not correlated to response of therapy/ risk, so don’t reassess BMD for at least 5 years

Question 17

Duration of therapy for osteoporosis

Answer 17

• For alendronate & zoledronic acid, continuing therapy for 5 years vs. 10 years increases risk of vertebral fractures; no difference in non-vertebral (5.3% at 5 years vs. 2.4% at 10 years for alendronate)
• Should discuss duration of therapy w/ px at baseline & at 5 years
• Drug holidays allowed as bisphosphonates stay in the bone for extended periods of time; reassess risk in 1 year

Question 18

Tips for good bone care/ hygiene

Answer 18

• Lifestyle (regular exercise, weight-bearing)
• Vitamin D
• Calcium
• Fall prevention (minimize hazards for falling in the home; assess drugs; improve strength & balance)
• Smoking cessation
• Dietary measures (encourage adequate protein, calcium & vit D intake, avoid excess alcohol & caffeine)

Question 19

Supplementation for osteoporosis. What are the harms?

Answer 19

• Calcium 1200 mg/day and vitamin D 800 IU/day
• Decreases risk of non-vertebral (5/1000 decrease/year) & high-risk hip fractures (9/1000 decrease/year)
• Harm:
• • Vitamin D –> negligible up to ~4000 IU/day
• • Calcium –> GI sx (nausea, constipation, bloating), hypercalcemia
• Dietary Ca preferred (300 mg each = 1 cup milk, ¾ cup yogurt)

Question 20

Is exercise recommended for osteoporosis? If so, what kind?

Answer 20

• Weight-bearing and stability
• Reduced rate/risk of falls (RRR ~ 30%)
• Small increase in BMD (up to 1%) over ~ 12 months
• Individualize for adherence and safety