Osteoporosis Flashcards
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
- Constitutional (non-modifiable)
Female, post menopause, ageing, late menarche, FHx, caucasian, short, previous low-trauma fracture - 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 - Lifestyle and nutrition
Smoking
Alcohol
Physical inactivity
Immobilisation
Low calcium
Vitamin D deficiency
Prevention
- Stop smoking
- Reduce alcohol
- Maintain adequate food intake and ideal body weight
- Increase weight bearing physical activity
- Adequate calcium and vitamin D
- Consider estrogen/progestin therapy
- 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
- Calcium carbonate 1.5g PO with food or
- 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
Hypercalciuria
Gonadal suppression
When steroids essential, reducing osteoporsis risk
- Use lowest dose
- Measure BMD prior to starting therapy and monitor regularly
- Minimise other risk factors
- Vitamin D supplementation
- Calcium supplement if dietary intake inadequate
- Bisphosphonates (alendronate) when: osteopenia/osteoporosis and will have >5mg prednisone for at least 3 months
Treatment of osteoporosis to prevent further fractures: general principles
- Restore mobility, fall prevention strategies
- Treat underlying conditions
- Establish severity->BMD
- Stratify fracture risk and choose appropriate therapy
- Modify underlying risks for fractures
- Monitor response to treatment
- Consider weight bearing exercise under guidance
Fall prevention
- Correct vit D
- Improve vision
- Review medication
- Assess household risks
- Aids for daily living
- Exercise
- Minimise immobilisation
- Hip protectors
- Tai chi
Investigating fractures->cause other than osteoP
- Suggestion of systemic
- Unusual persistent pain
- Unusual fracture pattern
- Recurrent fractures
- Minimal trauma fractures in men
- 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
Bisphosphonate
Alendronate
Risedronate
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
