Course:PostgradFamilyPractice/ExamPrep/99 Priority Topics/Osteoporosis

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Osteoporosis - Key Features

1. Assess osteoporosis risk of all adult patients as part of their periodic health examination.

2. Use bone mineral density testing judiciously (e.g., don’t test everybody, follow a guideline).

3. Counsel all patients about primary prevention of osteoporosis (i.e., dietary calcium, physical activity, smoking cessation), especially those at higher risk (e.g., young female athletes, patients with eating disorders).

4. In menopausal or peri-menopausal women, provide advice about fracture prevention that includes improving their physical fitness, reducing alcohol, smoking cessation, risks of physical abuse, and environmental factors that may contribute to falls (e.g., don’t stop at suggesting calcium and vitamin D).

5. In patients with osteoporosis, avoid prescribing medications that may increase the risk of falls.

6. Provide advice and counseling about fracture prevention to older men, as they too are at risk for osteoporosis.

7. Treat patients with established osteoporosis regardless of their gender (e.g., use bisphosphonates in men).

A condition characterized by decreased bone mass and microarchitectural deterioration of bone tissue causing increased bone fragility and susceptibility to fracture.

Etiology
- Primary Osteoporosis - Due to post-menopausal decline in estrogen and/or increased age
- Secondary Osteoporosis

- GI - malabsorption (previous gastric surgery, IBD, celiac ds), poor nutrition, chronic liver and renal disease
- Bone - multiple myeloma, lymphoma, leukemia, immobilization
- Endocrine - Cushing’s, hyperthyroidism, hyperparathyroidism, DM, acromegaly, estrogen deficiency (hypogonadism, premature ovarian failure)
- Inflammatory: rheumatoid arthritis, SLE
- Drugs – corticosteroids(#2 reason to cause OP), phenytoin, heparin, androgen deprivation Rx
- Psych – Anorexia nervosa, alcohol abuse


Screening
- *Canadian clinical practice guideline focuses on prevention of fragility # and their consequences, rather than treating low BMD
- All patients over 50 years of age should be screened for osteoporosis and fracture risk factors AND fall risk at their periodic health examination
- Assess 10 yr fracture risk with FRAX or CAROC
- Hx – prior fragility #, parental hip #, glucocorticoid use, smoking, high EtOH intake, rheumatoid arthritis, falls in past year, gait and balance
- PE – weight, height (historical loss >6cm or prospective loss >2cm), rib to pelvis distance < 2 fingers breadth, occiput to wall distance > 5cm, fall risk – Get-Up-and-Go Test
- Based on Hx and Px, look at indications for a Bone Mineral Density (BMD). Wide-spread BMD screening for those under 65 is not recommended.

Indications for measuring BMD
- All patients aged 65 yrs
- If age 50-64 yrs and

- Fragility fracture after age 40
- Prolonged use of corticosteroids*
- Use of other high risk meds **
- Parenteral hip fracture
- Vertebral fracture or osteopenia seen on Xray
- Current smoking
- High EtOH intake
- Low body weight (< 60 kg) or major weight loss (> 10% of body weight)
- Rheumatoid Arthritis
- Other disorders strongly asst’d with OP

- If age < 50 yrs and

- Fragility Fracture
- Prolonged use of corticosteroids*
- Use of other high risk meds**
- Hypogonadism or premature menopause
- Malabsorption syndrome
- Primary hyperparathyroidism
- Other disorder strongly associated with rapid bone loss and/or fracture


* corticosteroid >7.5mg prednisone ODx3months
** aromatase inhibitor, androgen deprivation therapy

Clinical Features
- Commonly asymptomatic
- May have pain, especially back
- Height loss or thoracic kyphosis
- Fractures – hip, vertebrae, humerus and wrist are most common

Investigations
- Usually have normal Ca, PO4, ALP
- Check CBC, Cr, TSH, vit D, SPEP/UPEP, 24 hr urinary Ca excretion, PTH.
- Lateral thoracic and lumbar spine X-rays if clinical suggestion of vertebral #

Bone Mineral Density: - Dual-energy X-ray densitometry (DEXA) is gold standard
- Measure density at lumbar spine and femur, then compared to gender and ethnicity-matched controls

BMD 1.0 - 2.5 SD below mean = Osteopenia
BMD > 2.5 below mean = Osteoporosis


Management
- Council all patients about primary prevention of osteoporosis

- Weight bearing endurance exercise (20-60 min 4-7 x/wk), balance & strengthening (2-4x/wk) exercises
- Smoking cessation
- Caffeine and EtOH reduction
- Dietary or supplemental calcium (1200mg/d) and vitamin D (400-2000 IU/day)

- Institute a fall prevention program for those at risk

- Address mobility and sensory impairments, dizziness, urinary frequency, hazards in the home
- Consider hip protectors if high risk and residing in long term care

- Prevent prescribing meds that increase fall risk

- Oral hypoglycemic agents, diuretics, anti-cholinergic, anti-hypertensive, psychotropic meds etc

- Correct a reversible cause if there is one
- Discontinue osteoporosis-inducing medication if possible

Treatment
Pharmacotherapy reduces risk of vertebral fracture by 30-70%
Canadian guidelines recommend treatment based on FRAX or CAROC 10 yr fracture risk:

- High Risk (>20%) or >50yrs with fragility fracture of hip/vertebra or >1 fragility fracture = pharmacological treatment
- Mod Risk (10-20%) – decision to treat with pharmacotherapy based on patient preference and additional risk factors (additional vertebral #, prev wrist # if >65 and T-score < -2.5, T-score lumbar spine <<femoral neck, rapid bone loss, men on androgen-deprivation therapy for prostate CA, women on aromatase inhib therapy for breast CA, long term/repeated systemic steroid use, >2 falls in past year, other d/o strongly associated with osteoporosis, rapid bone loss/#’s)
- Low Risk (<10%) – lifestyle measures are sufficient

For menopausal women,

- Bisphosponates (alendronate or risendronate) - prevents hip, nonvertebral and vertebral fractures
- Selective estrogen-receptor modulator SERM (raloxifene) - prevents hip fractures
- HRT – if woman has vasomotor Sx – prevents hip, nonvertebral and vertebral fractures
- If intolerant of first line therapies – calcitonin or etidronate – prevents vertebral fractures
- PTH or calcitonin – if has had previous fracture

For men,

- Bisphosphonates
- Testosterone not recommended

Study Guide

Osteoporosis

Resources

Papaioannou et al. 2010 Clinical practice guidelines for the diagnosis and management of osteoporosis in Canada: summary. CMAJ November 23, 2010 vol. 182 no. 17 www.cmaj.ca/content/early/2010/10/12/cmaj.100771.full.pdf+html
Toronto Notes 2010
BC Guidelines – Osteoporosis: Diagnosis, Treatment and Fracture Prevention. 2011 www.bcguidelines.ca/guideline_osteoporosis.html