oestoporosis Flashcards
what are the two components of bone matrix
calcium and collagen
what cells build bone
oestoblast
what cells breakdown bone
oestoclast
what cells sense changes in the bone
oestocyte
what is osteoporosis
a disease characterised by low bone mass and micro-architechtural deterioration of bone tissue leading to bone fragility and increased risk of fracture
what are the symptoms of osteoporosis
bone pain in back, hips, legs and feet difficulty walking/limited mobility easily fractured bones pain, disability and risk of premature death loss in height over time
osteoporosis most commonly affects ?
women - usually post menopausal
what is bone mineral density used to predict
osteoporotic fracture
what are the main factors that affect bone health
nutrition + environment physical activity genetics hormones smoking contributes to bone loss
what are the two main nutrients that are important for bone health
calcium and vitamin D
why is calcium important for bone health
main mineral in bones
gives bones their stiffness and strength
why is vitamin D important for bone health
promotes bone formation and mineralisation
also promotes uptake of calcium in the gut and reabsorption on the kidney
how does vitamin D deficiency affect bone health
impaired calcium mineralisation leading to rickets/osteomalacia
how can low sun exposure affect bone health
80-90% of vit D comes from sunlight
what populations are at risk of vitamin D deficiency
elderly/housebound
people who cover up all their skin in sun
countries at high latitudes
how can physical activity affect bone health
gravitational, muscles, ground reaction forces all impact bone health
bone adapts to these forces changing external shape and internal architecture
what factors contribute to an osteoporotic skeleton
weakened bone low BMD and mass poor trabecular and cortical architecture more bone resorption than formation low calcium and vit D
why do fractures occur
when applied load exceeds the strength of the bone
what are the three factors used in treatment of osteoporosis
drugs, diet and exercise
treatment of osteoporosis aims to reduce one factor and improve another, what are these factors
inhibit bone resorption
stimulate bone formation
what drugs are used to inhibit bone resorption
biphosphates - induce osteoclast death oestrogen receptor modulators - acts as oestrogen in bone and reduces osteoclast activity
what drugs are used to stimulate bone formation
parathyroid hormone - activates vit D which increases calcium absorption in the gut and increases bone formation
what are the negative effects of oestrogen replacement therapy
increased risk of breast cancer, CVD and stroke
what supplements would be suggested for those with osteoporosis
calcium 500-2000 mg / day
vit D 20ug microgram
exercise for those at high fracture risk
stair climbin, nordic walking,
no bending at waist, running any high impact
