osteoporosis Flashcards
define osteoporosis
significant reduction in bone density and structural deterioration
define osteopenia
less severe form of osteoporosis
difference between a Z score and a T score
T score - DIAGNOSTIC
the number of standard deviation points away from the score of the average healthy adult
Z score
the number of standard deviation points below a healthy adult matched by age, sex and ethnicity
what is a DEXA scan, how does it work and which bones are assessed
- xray
- measures bone density by how much radiation is absorbed by bones
- can be measured using any bones
- femoral neck most important
who would you refer for a dexa scan
- patients on long term corticosteroids
- > 50yrs with risk factors
- all females >65
- all male >75
what are the assessment criterias used in ospteoporosis and what do they measure
Q-fracture
FRAX
10yr risk of major osteoporotic fracture and hip fracture
management
first line:
- address risk factors - smoking and exersize and diet
- bisphosphonates
- AdCal - calcium carbonate + VitD
second line:
- denosumab - monoclonal antibody
also:
HRT
recombinant PTH
oestrogen receptor modulator - raloxifene
mechanism of bisphosphonates
- interferes with osteoclasts attaching to bone
side effects of bisphosphonates
- reflux and oesophageal erosions
- atypical fractures
- osteonecrosis of jaw
- osteonecrosis of external auditory canal
most common side effect of bisphosphonates
reflux and oesophageal erosions
how to tell patients to take bisphosphonates
taken on a full stomach with full glass of water and patient needs to sit upright to reduce oesophageal erosions
examples of bisphosphonates
alendronate
risedronate
zoledronic acid
risk factors for osteoporosis
- glucocorticoid use
- rheumatic arthritis
- alcohol excess
- history of parental hip fracture
- low BMI
- current smoking
SHATTERED
-Steroids
-Hyperthyroid/Hyperparathyroid
-Alcohol+smoking
-Thin (decreased BMI)
-Testerone (decreased)
-Early menopause (decreased oestrogen)
-Renal / liver failure
-Erosive + inflammatory disease
-DMT1 or malabsorption
medications that may worsen - other than corticosteroids
- SSRIs
- antiepileptic medications
- PPIs
- long term heparin therapy
- aromatase
- carbamazole
tests given to all patients
- FBC - myelomas ect
- U+E
- LFT - inhibit vitaminD metabolism
- bone profile
- CRP
- TFT
lab results
often normal Ca, phosphate and PTH
whats the mechanism of action of denosumab
inhibits RANKL
- rankl activates and develops osteoclasts used in patients with ckd
- unlinke bisphosphonate, isnt excreted by the kidneys
carbazepine
inc risk of osteoporosis
What proportion of women and men over age 50 will have a fracture due to osteoporosis? (2)
50% of women
1 in 5 men
T - score interpretation
> -1 Normal
-1 to -2.5 Osteopenia (precursor)
< -2.5 Osteoporosis
< -2.5 plus fracture is severe osteoporosis
what is post-meopausal osteoporosis
Loss of restraint effects of oestrogen on the bone turnover
what does DEXA stand for
dual energy x-ray absorptiometry
It’s also called a bone densitometry scan
What is a decrease in bone mineralisation known as?
osteomlacia
two types of treatments for osteoporosis
1) Anti-resorptive
- decrease osteoclast activity and bone turnover
- Bisphosphonate = 1st line
- HRT
- Denosumab
2) Anabolic
- Increase osteoblast activity and bone formation
- Teriparatide
