Patho: Exam 2 Osteoporosis/Pagets Disease/Hyperparathyroidism Flashcards
What is Osteoporosis:
Poris bone and reduced bone mass
What is the cause of Osteoporosis?
There are multiple causes ( Senile- primary type 2, Postmenopausea- primary type 1, Secondary)
What are some causes of secondary Osteoporosis?
Endocrine- Cushing disease, Neoplastic- Multiple myloma eating away at the bone, GI- any malabsorption of calcium, Drugs- steroids decrease calcium absorption and misc.
Stats
in the Unitied states 15% of people by the age of 80 have a hip fracture, 25% by age 90 have hip fracture.
Pathology of Osteoporosis
Decreased thickness of cortex
Reduction in number and size of trabeculae of cancellous bone
Type 1(postmenopausae): disrupted connections between trabeculae- increased osteoclast activity.
Type 2(senile): reduced trabecular thickness- loss of osteoblast activity
What does DEXA scan stand for?
Dual Energy X ray absorptiomety
Normal bone density:
Normal: Bone Mineral Density no lower than 1 SD below mean for young adult women: T>-1
Osteopenia
(Low bone mass): BMD 1.0-2.5 SD below the mean for young adults (T=-1 to -2.5)
Osteoporosis
BMD more than 2.5 SD below young adult mean (T<-2.5)
What is T versus Z score
T score- refers to the average bone density of a 30 y/o female
Z score- age and gender match.
Who needs to get a dexa scan?
Women >65, Men >70
If you break a bone after the age of 50
Women of menopausal age with risk factors
Man age 50-69 with risk factors
Other: An xray showing bone loss Back pain with possible break in spine Height loss > .5 in or more in one year Total heigh loss of greater than 1.5 in. from original
What is the most common location they look at on DEXA?
Dual Energy X ray absorptiomety
What can osteoperosis in the spine lead to?
Kyphosis or a dowager’s hump.
what is a Dowagers hump?
the type of kyposis seen in osteoporosis due to shorter vertebral does in the spine
What are some known factors that lead to osteoperosis?
oHereditary factors oPhysical activity oMuscle strength oDiet oHormonal state oAge related loss: 0.5% -0.7%/year
Primary Type 2- Age related loss AKA senile Osteoporosis
Primary Type 2- Age related loss AKA senile Osteoporosis
What is the problem in senile Osteoporosis
Reduced poligeration of the Osteoblast –they become sluggish
Proteins bound to matrix (Growth factors) lose biologic activity (Beta Catenin_)
Net result: decreased compasity to make bone
Both Trabecular and cortical bone is decreased
What are the Other causes of senile Osteoporosis?
Reduced physical activity- Mechanical forces stimulate bone remodeling
What evidence supports physical activity reduction leading to low bone density?
o Immobilized extremity
o Astronauts in zero gravity
oAthletes have higher bone density
Genetic factors leading to Osteoporosis
o Associated genes: RANK ligand, OPG, RANK
o Other implicated genes: Vit D receptors, LPR5, Estrogen receptor gene.
How can ones Nutritional state lead to Osteoporosis?
decreased vit d or Ca
What are the Ca+ intake recommendations?
o Adults under 50- 1,000 mg/day
o Adults over 50-1,200 mg/day
What are the Vit D intake recommendations?
o Adults under 50- 400-800 IU
o Adults over 50- 800-`1000IU
•What type of vit D should you order?
o Calcidiol- 25 hydroxyvitamin D not 125, because 125 has a short ½ life and wont give you a good reading
There are two types of measurement on lab what are they?
Nmol/L or ng/ml
What are the deficent, inadequate, adequate and bad levels of Vit D
o 50 nmol/L (> 30 ng/ml)= adequate
o >125nmol/L (>50 ng/ml)=bad- tooMUCH!
what is a side effect of taking to much Calcium?
The Ca+ suppliments are like candy, so people where taking in so much Ca+ but the side effect of SPIKED ca+ ( random increases) will lead to depositis of ca+ athrosclerosis in the vessels – new recommendations is just to get Ca in the diet.
Vitamin D can be obtained by the sun, how?
You need to spend 20 min in direct sunlight in the peak sun light everyday.
What are the two types of vit d and what is the difference between them?
D3: Cholecalciferol- what you actually make ( needs to go to the liver to become a hormone)
D2: Ergocalciferol
D3 has a longer half life.
For every 1000 units per day, after 1 mo, how much will it raise your vit D?
10 ng/ml.
What happeneds to Vit D levels as you age?
As one ages there is a decrease in renal 1 alpha-hydroxylase and less conversion of vitamin D to its active form
What are normal Vit D levels?
75 nmol/L or higher
30 ng/ml or higher but less than 50ng/ml
Primary Type I Osteoporosis- Hormonal Women:
Loss of 35% of cortical bone and 50% of their trabecular bone within 30-40 years after menopause: recognizable within 10 years after the onset of menopause.