osteoporosis and disorders of bone metabolism Flashcards
what are the cells responsible for the bone composition ?
osteocytes
osteoclasts
osteoblasts
what receptor is responsible for the regulation of bone remodeling balance ?
RANKL
what does RANKL do ?
makes sure the osteoblast activity is equal to the osteoclast activity
what does the remodeling balance look like in growth ?
formation > resorption
what does the remodeling balance look like in aging ?
formation < resorption
what is osteoporosis ?
brittle bone disease where bone mineral density of more than 2.5 standard deviation below that of normal adult mean value
what is osteopenia ?
level just before osteoporosis
where the bone mineral density of more than 1 standard deviation below that of normal adult mean value
what are the types of osteoporosis ?
primary
secondary
what are the causes of secondary osteoprosis ?
hyperthyroidism adrenal disease Rheumatoid Arthiritis Malignancy Immobilization Prolonged corticosteroid therapy
what do brittle bone disease increase the risk of ?
fractures
where are the common sites of fractures ?
neck of femur
vertebral fracture
wrist ( Colle’s fracture )
what are the modifiable risk factors of osteoprosis ?
Vitamin D deficiency smoking chronic alcohol use low physical activity corticosteroids and PPI
which entity of people are at higher risk of developing osteoporosis ?
females after menopause
why is vitamin D deficiency a risk factor for osteoprosis ?
decreased vit D levels results in increased PTH causing increased bone resorption
what can we give patients who are at higher risk ?
calcium ( 1000-1500mg/day) vitamin D ( 400-800 IU/day) alongside Biphosphonates RANKL inhibitor ( denosumab) Parathormone analogue Strontium ranelate Selective estrogen receptor modulator
what are the side effects of biphosphonates ?
osteonecrosis of the jaw
oesophaghitis
atypical femur
what is the pharamacological name of RANKL inhibitors ?
Denousmab
what is the mechanism of denosumab ?
inhibitionn nnof RANKL receptors thus inhibition bone resorption
what are the side effects of denosumab ?
wekaness , muscle pain
constipation n
rash
decrease calcium levels
what is the pharma name for parathormone analogue ?
teriparatide
what are the side effects of teriparatide ?
nausea, limb pain, headache
may be related to an increase risk of osteosarcoma
what are the side effects of strontium ranelate ?
nausea, diarrhea
increased risk of DVT
increased cardiovascular risk
what is the pharma name of selective estrogen receptor modulator ?
raloxifen
when is raloxifen indicated ?
in postmenopausal women
what are the side effects of Raloxifen ?
increased risk of DVT
increased cardiovascular risk
what does a DEXA scan interpretation tell us ?
T score :
is used to compare to a young healthy adult of the same gender
used to identify osteoporosis
Z score :
compared to a healthy person of the same age and gender
mainly used to identify secondary osteoporosis
what is Pagets disease ?
localized disorder of the bone metabolism with osteoblastic and osteosclerotic areas ( localized osteosclerosis)
what are the symptoms of pagets disease ?
nerve compression n
bone deformities
fractures
high output cardiac failure
what are the common sites for metastatic bone disease ?
breasts lung prostate kidney thyroid
in which areas of bone metastasis may the calcium be normal ?
breasts and prostate
what investigations can we perform for Pagets ?
ALP high
normal bone profile
normal liver profile
what can raise ALP ?
liver affection pregnancy during growth vitamin D deficiency hyperparathyroid
where would we need to do an X-ray ?
pelvis
long bones
what are the risk factors for osteonecrosis ?
fracture smoking, alcohol steroids sickle cell anemia radiation decompression sickness
