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Flashcards in Osteoporosis Deck (21)
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What is a T score

number of standard deviations their BMD at any major skeletal site deviates from the young adult mean for their sex

Osteoporosis if -2.5, osteopenia= -1 -> -2.5 on DXA


Clinical risk factors

1. Constitutional (non-modifiable)
Female, post menopause, ageing, late menarche, FHx, caucasian, short, previous low-trauma fracture
2. Diseases and drugs
a. Endocrine: -ve sex hormone, cushing, +thyroid, hyperPTH
b. Malabsorption: celiac, resection, bariatric
c. Chronic medical
d. Low body weight, weight loss
e. RA, CT
f. GlucoC, thyroid hormone, heparin, antiepileptic, anti-androgen, aromatase inhibitor
g. +risk of falls: balance, vision, muscle weakness, sedating/antiHTN
3. Lifestyle and nutrition
Physical inactivity
Low calcium
Vitamin D deficiency



1. Stop smoking
2. Reduce alcohol
3. Maintain adequate food intake and ideal body weight
4. Increase weight bearing physical activity
5. Adequate calcium and vitamin D
6. Consider estrogen/progestin therapy
7. Consider steroids and need for long term


Benefit of physcial actviity

Maintains strength, mass, flexibility, balance
Reduction in frequency and severity of falls
In premenopausal can +BMD, in post menopausal can reduce bone loss.
Non weight bearing does not increase BMD


Total daily calcium intake

at least 1000 mg in women 50 years or younger and men 70 years or younger
1300 mg in women older than 50 years and men older than 70 years.


Calcium suppplementation

Only if dietary intake is insufficient
1. Calcium carbonate 1.5g PO with food or
2. Calcium citrate 2.38g PO, daily
a. Calcium supplements taken in the evening may have the advantage of suppressing the nocturnal increase in bone resorption mediated by parathyroid hormone.
b. Calcium supplements can reduce the absorption of some other drugs (eg thyroxine, tetracyclines, quinolones, bisphosphonates) and should be separated from these drugs by at least 2 hours.
c. Long-term glucocorticoid administration impairs calcium absorption.


When to consider estrogen/progestin therapy

Younger post menopausal give estrogen/progestin therapy regardless of BMD.


Steroids causing osteoporosis mechanism

Reduced osteoblast function
Reduced intestinal calcium absorption
Gonadal suppression


When steroids essential, reducing osteoporsis risk

1. Use lowest dose
2. Measure BMD prior to starting therapy and monitor regularly
3. Minimise other risk factors
4. Vitamin D supplementation
5. Calcium supplement if dietary intake inadequate
6. Bisphosphonates (alendronate) when: osteopenia/osteoporosis and will have >5mg prednisone for at least 3 months


Treatment of osteoporosis to prevent further fractures: general principles

1. Restore mobility, fall prevention strategies
2. Treat underlying conditions
3. Establish severity->BMD
4. Stratify fracture risk and choose appropriate therapy
5. Modify underlying risks for fractures
6. Monitor response to treatment
7. Consider weight bearing exercise under guidance


Fall prevention

1. Correct vit D
2. Improve vision
3. Review medication
4. Assess household risks
5. Aids for daily living
6. Exercise
7. Minimise immobilisation
8. Hip protectors
9. Tai chi


Investigating fractures->cause other than osteoP

1. Suggestion of systemic
2. Unusual persistent pain
3. Unusual fracture pattern
4. Recurrent fractures
5. Minimal trauma fractures in men
6. BMD Z score lower than -2

If fracture with minimal force and BMD normal-> ++force than reported, underlying process : malignancy/stress fracture


Most common cause of osteoporosis in men

Sedentary lifestyle



Zoledronic acid


Side effects of bisphosphonates

Upper GI->esophagitis, gastitis, pain, ulceration
Nausea, dyspepsia, constipation, diarrhea, MSK pain, hypocalcemia, low phosphate
Unusual femur fractures reported
Osteonecrosis of the jaw


Pharmacotherapy options

Denosumab->reduction in osteoclast activity
Strontium ranelate


Monitoring osteoporosis treatment

BMD of lumbar spine and hip-> 2 years after therapy begins, 1-2 years after therapy changes significantly


Reasons for spinal BMD decrease by more than 3%/further fractures

1. Missed concurrent illness
2. Major risk factor
3. Poor therapy concordance


Fracture risk and T score

Every SD doubles fracture risk


Investigations to consider

Tests to consider
quantitative ultrasound (QUS) of the heel
x-ray (wrist, heel, spine, and hip)
quantitative CT
biochemical markers of bone resorption and bone formation
serum alkaline phosphatase->elevated in osteomalacia
serum calcium->low in osteomalacia, high in hyperPTH
serum albumin
serum creatinine->evidence of CKD
serum phosphate->low in osteomalacia
serum 25-hydroxy vitamin D
serum parathyroid hormone->hyperPTH
thyroid function tests->hyperthyroid
urinary free cortisol->cushings
serum testosterone (men)->young males w/ osteoporosis
urine protein electrophoresis->MM
serum protein electrophoresis


Taking a bisphosphonate

Bisphosphonates should be taken on an empty stomach, with a large quantity of water, and the
patient should remain in the upright position for at least 30 minutes. No food 2 hours either side.