Osteoporosis Flashcards
What are the risk factors of osteoporosis?
Older age Female Menopause Family history Rheumatoid arthritis Poor nutrition - low calcium d and vitamin d Sedentary - seated too long Smoking Alcohol Caffeine
What can improve bone mass and bone density?
Physical activity.
Mechanical loading
How is osteoporosis diagnosed?
Diagnosed by Dual Energy X-ray Absorptiometry (DEXA) scan
Measured bone mineral density
DEXA t score is the number of SD above or below a young healthy adult
Normal: > -1.0 SD
Osteopenia: -1.0 to -2.5 SD
Osteoporosis: _< -2.5 SD
Severe osteoporosis: _<2.5 with 1 or more fragility fractures
Where are the common sites for fractures?
Wrist, vertebrae, hip
What is the FRAX tool?
Algorithm that calculates 10 year probability of a major osteoporotic fracture
What is the first line treatment for osteoporosis?
Bisphosphanates - targets osteoclasts
How do bisphosphanates work?
Inhibits bone resorption by promoting the apoptosis of osteoclasts
How does denosumab work? Yeah
An antibody that binds to RANKL preventing it from bonding to RANK on osteoclasts —> reduced osteoclast activity.
How does saracatinib work?
Small molecule inhibitor of src kinase - inhibition of osteoclasts activity —> inhibits bone resorption
How does odanacatib work?
Small molecule inhibitor of Cathepsin K. Cathepsin K is a protease that osteoclasts need to degrade bone
How does Romosozumab work?
Monoclonal antibody that finds the WNT inhibitor sclerostin. Leads to activation of wnt pathway.
Promotes osteoblastogenesis and bone formation t
Dow does BHQ-880 work?
Monoclonal antibody that binds to the Wnt inhibitor DKK1.
Activation of wnt signalling
Promotes osteoblastogenesis and bone formation
How does MK-5442 work?
Antagonist of calcium sensing receptor.
CaSr suppresses PTH release from the parathyroid gland
Short burst of PTH release promotes bone formation
Antagonist therefore promotes PTH release therefore causes bone formation
