BSI Lecture 49-50 Osteoporosis Flashcards
What is the normal serum osmolarity value?
290 mOsm/L
T/F? Osteoporosis is the most common bone disorder.
True
Osteoporosis is generalized in that it includes all of what?
Osteoporosis includes all of the bones of the skeleton.
What are the two main characterizations of osteoporosis?
a) Loss of bone resulting from bone demineralization.
b) Increased brittleness due to decreased collagen.
As defined by the WHO (World Health Organization), how many standard deviations below the peak bone mass is the BMD of someone with osteoporosis?
2.5
What does BMD stand for?
Bone mass density
What is BMD measured by?
DXA (dual energy x-ray absorptiometry)
What is a T-score of >-1.0 considered?
normal
What is a T-score of -1.0 to -2.5 considered?
Osteopenic
What is a T-score of
Osteoporotic
What is a T-score?
The number of standard deviations from the bone density that is normally expected in a healthy young adult of the same sex.
What is a Z-score?
Your bone density compared with what is normally expected in a healthy adult of the same age and sex.
There are many causes of osteoporosis, but what is the final common outcome?
A reduction in the bone mass below a critical level, which causes an increased susceptibility to fractures.
What is the main difference between primary and secondary osteoporosis?
Primary osteoporosis is caused by cumulative bone loss.
What is Type 1 osteoporosis?
Postmenopausal osteoporosis
T/F? Type 1 osteoporosis is considered the most common type of osteoporosis.
True
What is the cause of Type 1 osteoporosis?
A lack of oxygen
Is type 2 primary or secondary?
Primary
What is type 2 osteoporosis?
Senile osteoporosis
What does type 2 osteoporosis deal with?
A decrease in the enzyme 1-alpha-hydroxylase
What is the function of the enzyme 1-alpha-hydroxylase, and where is it located?
This is an enzyme located in the kidney that activates vitamin D.
What type of osteoporosis falls under secondary osteoporosis?
Type 3
What is type 3 most often caused from?
disease or drug therapy
How many women and men over the age of 50 will experience an osteoporosis-related fracture?
1 in 2 women and 1 in 4 men
By 2050, what is the estimated amount of hip fractures?
6.3 million
How many people die within the first year after a hip fracture?
20%
Why is osteoporosis considered a silent disease?
The first symptom is a fractured bone
What area of bone is the area most affected? What are some examples of these bones?
Areas of bone with mostly spongy bone–The neck and femur are some examples.
T/F? In severe cases, contraction of the muscle in daily activity can cause a fracture.
True
What are common consequences of osteoporosis?
Pain, fear, isolation, depression, height loss, kyphosis
What is kyphosis, and what is the most common side effect of the condition?
Hunchback, which can lead to a compression of internal organs.
What may kyphosis restrict?
Lung function
What are some digestive problems potentially caused as a result of kyphosis?
Loss of appetite, constipation, abdominal pain and distention, and weight loss which may lead to more frailty
What are the risk factors for osteoporosis?
- Low peak bone mass
- Low calcium and vitamin D intake
- Lack of exercise
- Environmental factors
- Aging
- Low levels of estrogen
What is the primary effect of osteoporosis?
Genetics
What is the variance of peak bone mass accounted for by genetic factors?
80%, while the other 20% is accounted for by nutrition, exercise, and hormonal status
What are the two main environmental factors?
Smoking and alcohol consumption of more than 3 drinks/day
How does aging contribute to osteoporosis?
Loss of bone due to demineralization, and brittleness due to decreased synthesis of collagen.
How do low levels of estrogens contribute to osteoporosis?
Loss of estrogen during menopause, which decreases osteoblast activity, and increased activity of osteoclasts.
What are the targets of treatment for osteoporosis?
Treatment of fractures, management of pain from fractures, and pharmacologic therapies.
How do bisphosphonates work to treat osteoporosis?
Bisphosphonates promote osteoclast apoptosis. In addition, they inhibit bone resorption by osteoclasts. they impair osteoclasts from forming a ruffled border by attaching to hydroxyapatite binding sites on bony surfaces.
How does calcitonin work on osteoporosis?
Calcitonin inhibits the activity of osteoclasts.
How does Denosumab work on osteoporosis?
It is an antibody that binds RANKL
How does Recombinant PTH, such as Teriparatide, work on osteoporosis?
It activates osteoblasts more than osteoclast, which leads to an overall increase in bone. It is identical to a portion of human PTH.
How do estrogen and selective estrogen receptor modulators work on osteoporosis?
They aim to inhibit bone resorption by inhibiting osteoclasts.
Glucocorticoid-induced apoptosis is:
secondary osteoporosis
How do glucocorticoids impact osteoporosis?
They work to suppress the immune system, and osteoporosis is a side effect.
What effect does menopause have on the RANKL/RANK/OPG system?
decreased estrogen increases RANKL and decreases OPG. Estrogen normally functions to protect bone.
