Osteoporosis Flashcards
Typical demographic
Older females
Major risk factors for osteoporosis
steroid use
rheumatoid arthritis
alcohol excess
Family Hx
low body mass index
current smoking
Other (non major) risk factors
- sedentary lifestyle
- premature menopause
- Caucasians and Asians
- endocrine disorders
- multiple myeloma, lymphoma
- GI disorders: IBD, coeliac, gastrectomy, liver disease
- CKD
- osteogenesis imperfecta
- homocystinuria
Give examples of medications which may worsen osteoporosis
SSRIs
antiepileptics
proton pump inhibitors
glitazones
long term heparin therapy
aromatase inhibitors e.g. anastrozole
What investigations must be completed after a patient develops a fragility fracture?
Bloods: FBC, CRP, calcium, albumin, creatinine, phosphate, ALP and liver transaminases, TFTs
Bone densitometry ( DXA)
What is the T score used in DEXA scanning?
T score: based on bone mass of young reference population
T score of -1.0 means bone mass of one standard deviation below that of young reference population
What is Z score in DEXA scanning?
Z score is adjusted for age, gender and ethnic factors
Explain the cut offs for the T score and how someone maybe diagnosed with osteoporosis
> -1.0 = normal
-1.0 to -2.5 = osteopaenia
< -2.5 = osteoporosis
When is the risk of osteoporosis thought to rise significantly in patients taking steroids?
taking the equivalent of prednisolone 7.5mg a day for 3 or more months
If a patient is on steroids and is >65years with a history of previous fragility fracture, should they receive bone protection
Yes
If a patient on steroids is <65 with no history of fragility fracture, how do we decide if they require bone protection?
DEXA scan
T score:
>0 = Reassure
Between 0 and -1.5 = Repeat bone density scan in 1-3 years
< -1.5 = Offer bone protection
First line agent
Alendronate
If patients cannot take alendronate, what should be used instead?
Risedronate or etidronate
Other osteoporosis treatments
strontium ranelate
raloxifene
denosumab
Raloxifene mechanism of action
selective oestrogen receptor modulator (SERM)
Raloxifene side effects
may worsen menopausal symptoms
increased risk of thromboembolic events
may decrease risk of breast cancer
Adverse effects of strontium ranelate
increased risk of cardiovascular events and
thromboembolic events
may cause serious skin reactions such as Stevens Johnson syndrome
Mechanism of action of strontium
increases deposition of new bone by osteoblasts
(promotes pre-osteoblasts to become osteoblasts)
reduces the resorption of bone by inhibiting osteoclasts
Mechanism of denosumab
human monoclonal antibody that inhibits RANK ligand
in turn inhibits the maturation of osteoclasts
how is denosumab given
subcutaneous injection every 6 months
What is teriparatide and what is its mechanism of action
recombinant form of parathyroid hormone
HRT has been shown to reduce the incidence of vertebral fracture and non-vertebral fractures. TRUE/FALSE?
TRUE
- Due to increased rates of cardiovascular disease and breast cancer it is no longer recommended for primary or secondary prevention of osteoporosis
