osteoporosis Flashcards
can osteoporosis occur in young adults
yes
how is the relationship btw osteo and pa
important
which meds can lead to osteo
all anti inflammatory meds
what is osteo and why is it called like this
metabolic disease of b
osteo = b
porosis = porous (cavities in the b)
what is the osteo diagnosis
BMD measurement
what is the dual energy x-ray absorptiometry (3)
dexa
scans entire body and measures risk for fx in hip, spine and wrist
level of radiation is low and the test takes less than 5 min
provides 2D (cm^2) images of successive b layers
what is quantitative computed tomography (QCT) (4)
measures BMD in the hip and spine and produces a three dimensional image that allows true volume density QCT
can isolate an area for testing
the radiation is 10x higher than DEXA
the only method capable of distinguishing BMD level btw ext cortical b and int trabecular b (where b loss begins)
BMD measurement (2 types of scores)
BMD measurement is given as a T-score and a Z-score
t-score: the deviation from the mean b density of healthy young adults of the same gender and ethnicity
z-score: deviation from the mean b density of adults of the same age, gender and ethnicity
how does the WHO define osteo
T-score of -2.5 S.D and below is osteo
T-score btw -1 S.D & -2.5 S.D indicates some b loss (osteopenia) and a risk of osteo
if BMD of healthy young adults for the hip is 1000 +_ 100 (S.D) mg/cm^2
osteopenia = BMD of 900 to 750
osteoporosis = BMD of 750 and below
CHECK CALCULATIONS IN SLIDE
what is established osteo
preferred term for those with osteoporosis and having one or more fragility fx
what is a fragility fx
any fall from a standing height or less, that results in a fx
why is a fragility fx not just a normal fx
bc the body should be able to sustain a fall from this height w/o a fx unless there is an underlying cause that makes the b fragile
what are the most common areas for fx
wrists, hips and spine
every standard deviation below normal doubles the risk for fx
- 1 standard deviation = 2x risk of fx (osteopenia)
- 2 = 4x (osteopenia)
- 3 = 8x (osteoporosis)
how is a Z-score used
used to determine whether the loss of b density is secondary to another disease or condition: if it is lower than expected for age , then there must be something accelerating this loss beyond the normal process of aging
what types of drugs could cause a low z-score
corticosteroids, anticonvulsants, antirejections drugs, etc
what could cause a low z-score
drugs, alcohol, tobacco, eating disorders, etc
prevalence of osteoporosis
1/4 women over 50 yo is affected
1/8 men over 50 is affected
race and sex differences
more women than men bc lack of hormone from menopause and bc they have overall smaller b
what is the cost of osteo per year
4.6 billion
which is more common in hip fx; fall due to the femoral neck fx or fx is the result of the fall
fx is the result of the fall (80%)
facts about fx
over 60 yo: 18% fx of vertebrae
over 50 yo: 15% hip fx
women aged 65-69 who break a hip are ___ times more likely to die within a year than women of the same age who dont break a hip
3
percentages of women in WHO categories normal
25 yo: normal
50 yo: decrease
65 yo: decrease
80 yo: decrease
percentages of women in WHO categories osteopenia
25 yo: normal
50 yo: increase
65 yo: increase
80 yo: decrease (bc they become osteoporosis)
percentages of women in WHO categories osteoporosis
25 yo: normal
50 yo: normal
65 yo: increase
80 yo: increase
percentages of women in WHO categories established osteoporosis
25 yo: normal
50 yo: normal
65 yo: increase
80 yo: increase
bone metabolism
bone = living tissue
every 3-4 months = bone remodeling (old b is removed and replaced by new b)
what are osteoclasts?
bone eroding cells that dissolve the mineral and cause small cavities
what are osteoblasts
bone forming cells that fill in the cavities until it is restored
what is the diff btw decalcification and calcification
decalcification = bone resorption calcification = bone formation
what is the product of bone metabolism
new mineralized bones
aging effects; unbalance in b remodeling process
loss of 1% of total bone mass each year after the age of 20 (= peak)
loss of 2-3% of total bone mass each year in women after menopause (first 5 years)
what is the worst case scenario for unbalance in b remodeling process
3% for 5 years, so 15% for the whole body
aging effects; what is less efficiently absorbed
calcium
what are aging effect on b mineral density
see slide 18 for graph
how can we positively change/influence the BMD slope
better nutrition, physical activity and hormones in post menopausal women
hormones in control of b remodeling process (examples of hormones, role, …)
parathyroid hormones, estrogen, testosterone
role: to maintain the appropriate level of calcium in the b
the Ca controls the activity of b cells
(Ca levels –> HORMONES –> b cells –> BMD)
lack of hormones = bone atrophy
general response of the whole skeletal system (whole body)
mechanical loading in control of b remodeling process
required to maintain adequate b density
(loading; m contraction –> activation of b cells –> BMD)
absence of loading = b atrophy
this is why exercise is so important in middle-aged women and men
local response of the skeletal system
is mechanical loading alone or hormones enough to maintain your BMD (okay with 1 or need both??)
need both, one is not enough
what leads to compression fx and flattening of the vertebrae
the bony trabeculae are thinned out and the mechanical strength of the vertebra is reduced
where does the degeneration occur first
in spongy bone
for most fx = …
damages are limited to the front of the vertebral column = rarely associated with spinal cord damage
typical posture will do what over time in osteoporosis patients
rounding of shoulder, taking hormones can help
what are some risk factors beyond your control (direct effect on b remodeling process**) for osteo form osteo québec (9)
- family history of osteo (genetic predisposition)
- female
- small boned
- menopausal**
- caucasian or asian descent
- prolonged hormonal imbalances (thyroid gland)**
- removal of ovaries or premature menopause (before age 45)**
- prolonged use or heavy doses of certain medications**
- over the age of 50
what are some risk factors you can control for osteo form osteo québec (5)
- lack of pa = decrease in mechanical loading
- diet poor in Ca and vit D**
- smoking**
- caffeine (more than 3 cups a day)**
- excessive consumption of alcohol**
** : decrease of calcium in bones
when should someone consult a HCP
if you checked off more than 5 risk factors, see a HCP that can guide your course of prevention = physician + dietitian + kinesiologist
what are the 3 classifications of osteo
postmenopausal osteo (type I) senile osteo (type II) secondary osteo (can occur in young people)
postmenopausal osteoporosis characteristics (5)
- decrease in estrogen = decrease 10-15% BMD in the first 5 years
- most common
- only women
- mid sixties (= 15 years post menopause)
- vertebral and hip fx
senile osteoporosis characteristics (3)
- over 80 yo, normal for people this age
- 30% are men, 70% women
- forearm, pelvic and hip fx (#1)
secondary osteoporosis (6)
- can occur in young people
- associated with calcitonin imbalance, malabsorption conditions (celiac disease, cystic fibrosis, lactose intolerance), alcoholism, smoking and the use of certain medications (glucosteroids in arthritis)
what is celiac disease
inability to metabolize peptides in gluten (wheat, oats, barley) Lead to m. wasting
prevention of osteo
hormone replacement therapy (estrogen)
what are the pros and cons of hormone replacement therapy
pros:
inhibits or slows down b resorption
decreases effects of menopause (ex: hot flashes, night sweats)
cons:
Slightly increase risks of blood clots, stroke and coronary heart disease
necessary or not?
what is the best kinds of pa for prevention of osteo
weight-bearing activities:
-walking, running, dancing + games and sports such as badminton, tennis, basketball, soccer, etc
resistance exercise:
-weight training done w barbells or dumbbells or various apparatus (ex: nautilus)
-special consideration: high intensities and few reps to increase b pressure
effects of exercise on the bones
increase pressure on the b = increase in b mass (sites specific to the limbs used)
secial considerations to exercise (osteopenia and osteoporosis)
avoid flexion of the spine
adapt equipment for decreased risk of falling (falls can = fx)
aerobic dance exercise = low impact
resistance training = decreased load and increased reps
