Osteopenia & osteoporosis porfoma Flashcards
What is osteoporosis?
- Condition characterised by low bone density
- Results in increased bone fragility & susceptibility to fracture.
- T-score less than -2.5
What is osteopenia?
- Reduced bone density than average for your age, but not low enough to be classed as osteoporosis.
- T-score between -1 to -2.5
Epidemiology of osteoporosis?
- Fractures affect 1 in 3 women & 1 in 5 men aged over 50 years old
- More than 120,000 people receive hospital treatment for fragility fractures every year due to osteoporosis.
- Common to fracture: spine, neck of femur & wrist - 20% are hip fractures.
- proximal humerus & pelvic fractures fairly common too
Pathophysiology of osteopenia & osteoporosis
- Osteoblasts become less effective = lay new bone at slower rate.
- And don’t live as long either.
- Osteoclasts = continue at same rate.
- Osteoclasts start to outwork the osteoblasts = out of balance.
NOTE: view diagram on notes
Risk factors for osteopenia & osteoporosis
SHATTERED FAMILY:
- Steroid use
- Hyperthyrodism
- alcohol & tobacco
- thin (low BMI)
- Testosterone- low
- early menopause
- renal/liver failure
- Erosive/ inflammatory bone disease
- Diet- low Ca & vit D
- family history
Non modifiable:
1. Age:
- Peak bone mass reached at around 30 years.
- It stays fairly stable until out 40s & 50s.
- Menopause brings women closer to fracture threshold.
- Men have higher starting bone density so further from fracture threshold.
2. Sex- females
3. - Previous fragility fracture
4. Endocrine e.g. early menopause
5. Parental history of hip fracture
Modifiable:
1. Low BMI - we need some body fat to metabolise oestrogen. - Oestrogen has a protective effect because it influences RANK:OPG ratio to increase osteoblast activity.
2. Lifestyle - smoking, alcohol intake both reduce osteoblast activity.
Drugs:
1. Glucocorticoids - reduce the body’s ability to absorb Ca & increase bone resporbtion.
2. Heparin
3. PPIs - leads to decreased intestinal absorbtion of Ca = less Ca for bone mineralisation.
4. Epileptic drugs - increase the levels of chems in the liver than destroy vitamin D.
Co-existing co-morbidities
1. Diabetes mellitus
2. RA
3. SLE
4. Epilepsy- due to drugs taken
5. HIV
Bone density factors- determined by genetics, not just age:
- Skeletal geometry- shape of joints e.g. neck of femur can be different.
- Body weight
- Sex hormones - menopause - different people have different hormone levels & start menopause sooner than others.
- Racial factors - seldom seen in African descent. Asian descent = higher risk.
- Diet- protein needed as bricks & vit D is the cement.
- Exercise - loads skeleton & causes weight bearing.
Presentation of osteopenia & osteoporosis
Often asymptomatic
Those who had fractures, may present w/ focal pain, deformity & immobility.
- Colles fracture of wrist, fractured neck of femur & vertebral body fracture.
- Loss of bone in vertebrae is often anterior.
- So they loose height & become curved (kyphosis) = difficult to eat & breathe. More likely to get chest infections, have spinal cord encroachment & Bad balance
NOTE: view notes for image of fractures
Investigations for osteopenia & osteoporosis: blood tests
- FBC
- LFTs & U&Es
- Serum calcium (albumin adjusted)
- Alkaline phosphatase
- 25-hydroxyvitamin D
- PTH
- Endocrine - sex hormones, diabetes, cortisol
- Urine calcium excretion
Investigations for osteopenia & osteoporosis: imaging
DEXA
- Duel-energy X-ray absorptiometry
- score uses standard deviations.
Higher than -1 = normal= low risk of fractures
-1 to -2.5= osteopenia= above average risk of fractures
Lower than - 2.5= Osteoporosis= high risk of fractures
- T score is where patient is compared w/ normal person who is 20. This is the one commonly used.
- Z score is where a patient is compared w/ normal person who is same age, sex & ethnicity.
X-rays for fractures
MRIs
Management for osteopenia & osteoporosis: conservative
Aim:
- To reduce the risk of fractures
- Aim: Prevent individual w/ osteopenia from progressing into osteoporosis
^ same for pharmacological
Lifestyle changes - increase weight-bearing exercise e.g. climbing stairs, stop smoking, reduce alcohol consumption.
Get outside more.
Underweight people to gain weight.
Diet changes - eat foods that are rich in Calcium & Vitamin D e.g. spinach, fish, broccoli, beans, cheese, milk, yoghurt, cereal. More protein.
- High calcium diet e.g. milk, cheese, yogurt
- High in protein rich foods e.g. meat & fish
- High in omega-3 e.g. oily fish
- High in vitamin K e.g. green leafy vegtables
- Low in salty foods e.g. table salt, processed food
- High in fruit and veg (lots of potassium)
Falls clinics to try &reduce risk of falling.
- Look for medical reason for falls & get OT & Physio involved.
FRAX score - method to calculate risk of fracture to help guide management- formula uses factors such as:
- age
- weight
- gender
- smoking history
- alcohol use
- fracture history
Management for osteopenia & osteoporosis: Pharmacological
- Bisphosphonates e.g. Alendronic acid, ibandronate, risedronate, zoledronic acid.
- 1st line treatment for osteoporosis.
- works by inhibiting osteoclast activity, preventing the reabsorption of the bone.
- Contraindicted if eGRF is less than 35 mL/min i.e. chronic kidney disease or renal failure.
NOTE: bind to hydroxyapatite when acid is released, causes apoptosis of osteoclasts
- when taken sit up straight for 30 mins as can cause acid reflux- MIAN SIDE EFFECT!
- once a week orally or once a week intravenously
- Calcium supplementation w/ Vitamin D - always give w/ bisphosphonates.
- Denosumab
- monoclonal antibody that targets RANKL
- once every 6 months injection.
- Stops osteoclast differentiation & up-regulation. - Teriparatide
- PTH analogue.
- Expensive but useful in patients intolerant to other treatments.
- Intermittent PTH exposure causes an ↑ in osteoblast activation (above that of osteoclasts) & so results in net BMD increases. - HRT - hormone replacement therapy e.g. oestrogen.
- Check drugs patient is taking e.g. steroids and change if needed.
Prognosis for osteopenia & osteoporosis
- Good prognosis if appropriate measures are taken to prevent the reduction in bone density & strength.
- Good only if the appropriate diet & exercise recommendations are followed.
- Can progress into osteoporosis if an individual w/ osteopenia has a poor diet & lack/no exercise.
