Bone Health and Osteoporosis Part 1 Flashcards
what is our bones composed of?
- 50% mineral crystals (calcium phosphate)
- 50% protein (collagen)
- trabecular (quicker turnover) and cortical
what is trabecular bone?
spongey and its at the ends of our bones
- regenerates quicker than cortical
what is cortical bone?
compact and it is the outside layer of our bones
is bone alive?
yes
other than structure and protecting our organs, what is the bones function?
- secretes a lot of substances into the blood that can affect many other things
- it is continually broken down and reformed
what is bone modeling?
our bone growing at the ends (how we get taller)
- pediatric bone accrual
what is bone remodeling?
- adult bone turnover
- as we get older are bone can chip or become damaged so it rebuilds new bone over time
how does the bone remodeling cycle work?
- starts with osteoclast (bone break down cells)
- osteoclasts start to eat away at bone to create a pit
- osteoblasts get recruited to area to lay down new bone
- in order for this to happen, nutrients and building blocks are needed
- nutrients and osteoblasts work together to fill in certain area and build strong bone together
- inadequate nutrition = compromise process
what is the difference between osteoBlasts and osteroClasts?
Blasts: bone forming/Building cells (sit on surface of bone)
Clasts: bone resorbing cells
what does the balance between resorption and formation over time dictate?
bine mass or bone mineral density
osteoporosis
more brittle bones over time
- caused by too much resorption not enough formation (uncoupled)
what female hormone is really important for maintaining bone mass
estrogen. this is why bone mass starts decreasing at menopause, estrogen levels deplete
why do females develop osteoporosis at a higher rate than males?
bone loss earlier on at a faster rate due to menopause
what are the two main considerations regarding bone health over the lifespan?
- maximize achievement of high peak bone mass when young
- as we get older, prevent loss
- do so with diet and exercise
how does Osteoporosis Canada define osteoporosis?
“pediatric disease with geriatric consequences”
what is osteoporosis?
a skeletal disorder characterized by:
- compromised bone strength
- how much our bones can withstand
pressure (density and
microarchitecture)
- predisposition to an increased risk of fracture
- fragility fractures (minor trauma: fall
from a standing position)
- bones are thin due to mineral loss and are vulnerable to fracture
what type of bone does osteoporosis affect more?
- trabecular bone more (spongy)
- regions with high trabecular bone = fracture sites (ex. wrist, femoral neck, vertebral bodies)
how is osteoporosis diagnosed?
using DXA scans –> assess risk by comparison to healthy young adults
- T-score less than or = to -2.5 at any site
what do bones look like under a DXA scan for someone with osteoporosis?
bone will appear less bright white and more dull white
- harder and more mineralized if bright white
what are the 2 main clinical sites for osteoporosis diagnosis
- lumbar spine
- femoral neck (hip)
what ratio of men and women get osteoporosis?
1 in 5 men
1 in 3 women
risk factors for osteoporosis?
- starting peak bone mass (BMD)
- rate at which it is lost
- diet (key vitamins and minerals are vitamin D and calcium)
- exercise
- age
- sex
- genetics
- smoking and alcohol
what are symptoms of osteoporosis?
- bone pain (could mean micro-fractures)
- height loss (compression fracture in vertebrae) (a hunch back as well; dowager’s hump / kyphosis)
- night cramps in legs and feet
- fatigue
- non-traumatic/fragility fractures
what is colles’ wrist fracture in osteoporosis?
the distal radius fracture (outside forearm bone closest to inside elbow) - break a fall with outstretched hands
what are the hip fractures in osteoporosis?
- at femoral neck
- intertrochanteric line
- proximal shaft
- all three are in areas of trabecular bone
what type of fractures are increased once age 65 is hit?
mostly hip fractures, then vertebrae fractures
what type of fractures are associated with greater mortality following fractures?
hip and spine
what to do to treat and prevent osteoporosis?
- calcium
- vitamin D
- protein
- exercise
- medication
when do you realize you have osteoporosis?
when its too late and you’re getting fractures and in bone pain
what percentage of calcium in our body is stored within our bones?
98%
what are the calcium recommended dietary allowance (RDA) for children, adolescents, young adults and older adults?
Children: 1000mg/d (ensure enough for bone growth) (insufficient can result in growth stunt)
Adolescents: 1300mg/d (ensure enough for bone growth)
Young adults: 1000mg/d (maintain bone mass and prevent loss)
Older adults: 1200mg/d (prevent bone loss/osteoporosis)
how much mg of calcium is in a cup of milk?
300mg
why do we need to shake some beverages before drinking them?
calcium grinds fall to the bottom, so if we shake the bottle it will re-dispense into the full bottle
what vitamin is essential for the absorption of calcium?
vitamin D
RDA for Vitamin D
- under 70yo = 600 IU / day
- over and at 70yo= 800 IU /day
where can we find vitamin D?
- sun exposure
- fatty fish, egg yolks, fortified milk, margarine, juices
why is there a risk for deficiency of vitamin D in Canada?
- our latitude on the earth
- not enough sunny months
- not strong enough UV
what does osteoporosis Canada recommend to all Canadian adults regarding vitamin D?
vitamin D supplements
adequate supply of amino acids is essential for?
bone. collagen is 50% of our bone composition and collagen is a protein
is collagen a protein?
yes.
what is the most readily available dietary sources of calcium?
dairy/milk products; they are also high in protein and other micronutrients
are canadians getting enough protein?
yes. 16% of our diet. we are consuming above the RDA with respect to protein
is the RDA protein amount sufficient to keep disease like osteoporosis in older adults?
no, however, because canadians consume more than the RDA on average, this could ward it off
are canadians getting enough vitamin d and calcium?
no, the 2015 research showed that non-supplement users are getting less than in 2004. Supplement users stayed the same for calcium and got better for vitamin d
vitamin d inadequacy in 2015 in canadians?
non-supplement users: 97%
supplement users: 14%
calcium inadequacy in 2015 in canadians?
non-supplement users: 68%
supplement users: 32%
