5.1 Clincal - Osteoporosis Flashcards
Give the definition of Osteoporosis? (characterized by what, associated with what, results in what?)
Characterized by low bone mass.
Associated with reduced bone strength.
Results in increased risk of fractures.
Regarding diagnosis of osteoporosis what is the only attribute of bones that we can currently measure? (AKA what does DXA measure).
Bone Mineral Density (BMD).
DXA measures bone mineral content and bone area, then calculates areal BMD.
In the image what is occurring in osteoporotic bones. Give the description that is hidden by the boxes.
Fewer and thinner trabeculae.
Thin cortical bone.
Regarding the spongy centers of these bones, what is the difference (what is occurring in the osteoporotic bone)?
Bone on left is healthy. Has lots of hard fibers connected to each other.
Bone on right = osteoporosis. Spongy center has fewer, thinner fibers that are no longer connected. Surrounding shell of compact bone is thinner. Makes bone weak, that is why it fractured.
Another photo of osteoporotic bone. Appreciate how the two cotices and trabeculae are different. Click for description.
Cortices are thinner and more porous.
Trabeculae are fewer, thinner, disconnected and further apart.
What is the difference between osteomalacia/rickets and osteoporosis?
Osteomalacia/ rickets = increased unmineralized osteoid with softening of bones deficiencies.
Osteoporosis = disrupted microarchitecture and low bone mass with thin and weak bone spicles, normal mineralization. (no deficiencies, affects previously made bones).
Regarding bone resorption and bone formation, what is occurring in osteoporosis?
Resorption of bone exceeds formation, low bone mass (osteopenia).
May result in osteoporosis.
What are the 3 types of osteoporosis?
Primary (type 1) = postmenopausal.
Primary (type 2) = senile.
Secondary = underlying disease.
Regarding osteoclasts and osteoblasts, what is occurring in menopausal vs. senile type osteoporosis?
Menopause = increased osteoclast activity.
Senile = decreased osteoblast activity.
Who is at the highest risk for osteoporosis? Why do we even care about osteoporosis it’s not like it kills people….?
White/ Asian women.
Post-menopaus.
Old.
Smokers.
Drinkers.
Non-exercisers.
Osteoporosis leads to fractures, leads to falls, leads to surgerys and injuries, leads to a ton of health care costs and problems for those who suffered the fall!
What is the role of RANK-L in bone function? (lead me through the process). What could be a possible pharm technique regarding RANK-L to decrease osteoporosis?
RANK-L (ligand) binds the RANK receptor on osteoclast precursor cells and activates them to turn into osteoclasts and go to work => breakdown of bone.
Use a mab to bind the ligand.
What is the role of WNT in bone structure? (2 major roles)
Osteoblast maturity.
WNT also increases OPG which blocks RANK-L => less osteoclast activity.
When menopause comes around, what happens to OPG, and how?
Estrogen increases OPG levels.
Less estrogen => less OPG => more RANK-L => more osteoclast activity.
What is sclerostin, what is its role in osteoporosis and pharm regarding osteoporosis?
Sclerostin is secreted by mature osteocytes, leads to inhibition of bone formation.
Sclerostin inhibitors would lead to higher bone mass.
Summary card. Enjoy!
How can you diagnose osteoporosis if you are worried about it with a patient?
Labs can help exclude secondary causes.
CBC, calcium, phosporous, kidney and liver, serum 25(OH) D level, TSH. Can help to determing susceptibility due to any deficiencies in these important bone molecules.
You can also montior Rx using the box below.
DEXA scan is the most important for bone density.
Interpret T-Scores.
Give me the levels for normal, Low bone mass (osteopenia), osteoporosis, severe osteoporosis.
Normal: -1.0 or above.
Low bone mass (osteopenia): below -1.0 and above -2.5.
Osteoporosis: -2.5 or below.
Severe osteoporosis: -2.5 or below and personal history of fragility fracture.
