Osteoporosis Flashcards
most common skeletal disorder
osteoporosis
What is osteoporosis
a disease characterized by low bone density and weakening of bone tissue associated with an increase in fragilty and vulnerability to fracture
most common fracture sites with osteoporosis
hip, spine, wrist
osteoporosis most common in what gender
female - postmenopausal
What race/s have most risk for osteoporosis
caucasian, asian > hispanic> African american
osteoclast function
bone resoption
osteoblast function
bone formation
rank is on what
osteoclast
rank L is on what
osteoblast
OPG function
inhibition Rank L (regulates bone resorption)
6 stages of bone remodeling
initiation, activation, resorption, reversal, formation, quiescence
Initiation stage what occurs
PTH and low calcium in blood signal bone remodeling to begin
What occurs in activation phase
RankL binds to Rank shifting osteoclast precursors to mature osteoclasts
Resorption phase what occurs
a cavity in bone is created
what occurs in reversal phase
resorption stops, OPG binds to rankL
what occurs in formation phase
osteoblasts deposit in cavity
What is quiescence
rest
Populations at risk of low vitamin D intake
malnourished/obese, long term care facility, northern latitudes
Vitamin D 2
ergocalciferol
vitamin D3
cholecalciferol
active vitamin D
calcitriol
when to give active vitamin D
kidney disease may impair activation
Major Risk factors for osteoporosis
low bone mineral density female elderly caucasian/asain history of fractures family history of fracture low body mass past or present glucocorticoid use (5+ mg Prednisone for > 3 months) cigarette smoking excessive alcohol use (3+ /day)
secondary causes of osteoporosis
disease states
medications
disease states that cause osteoporosis
genetic diseases hormonal deficiency (premature menopause < 45 y/o) Endocrine disorders GI disorders Autoimmune diseases CNS disorders Alcholism COPD
Medications that cause osteoporosis
aluminum anticoagulants anticonvulsants aromatase inhibitors barbituates chemotherapy cyclosporine and tacrolimus depo-medroxyprogesterone glucocorticoids GnRH antagonists and agonists lithium methotrexate PPI SSRI tamoxifen (premenopausal use) TZDs excess thyroid hormones parenteral nutrition
fall risk factors
loose throw rugs low lighting obstacles in path slippery conditions lack of assistive devices
Clinical presentation of osteoporosis
no warning signs
pain/immobility
kyphosis
height loss > 2 cm
FRAX score tells what
10 year probability of hip fracture, major fracture (vertebral, forearm, proximal humerus)
limitations of FRAX
men 50+ and postmenopausal females only
for those not currently receiving Rx osteoporosis treatment
does not consider cumulative effect
Risk factors included in FRAX
age gender prior osteoporotic fracture femoral neck BMD low body mass oral glucocorticoids RA type 1 DM hyperthyroidism hypogonadism premature menopause malnutrition chronic liver disease parental history of hip fracture smoking alcohol intake
What should vitamin D levels be?
30 ng/ml
Use of a peripheral bone mineral density
screening
perpiheral bone mineral density site area
forearm, heel, finger
best candidates for peripheral bone mineral density
postmenopausal women without major risk factors
benefits of peripheral bone mineral density
less expensive than DXA
easy to use, portable, fast
project general fracture risk
Central DXA site use
diagnosis of osteoporosis and osteopenia
Central DXA areas
lumbar spine and hip
Central DXA results
bone density value, T score and Z score
DXA scans for who
women 65+, men 70+
postmenopausal women, women in menopause, and men 50-69 with risk factors
adults with fractures after 50
adults with conditions or medications associated with low bone mass or bone loss
Use of actual bone density
therapy response
T-score use
diagnosis of osteoporosis
What is T score
pt BMD compared to BMD of healthy, young, sex match white reference population
What is Z score
pt BMD compared to BMD of age matched, sex matched reference population
Z score is used for what populations
children, premenopausal women, men <50 y/o
Osteopenia T score
-1.1 to -2.5
Osteoporosis T score
<-2.5
Goals of therapy for osteopenia or no h/o of fracture
improve bone mass
prevent fracture
Goals of therapy for osteoporosis with fracture
eliminate/decrease pain
maintain funcitonal status
improve QOL
prevent future falls or fractures
NON pharm therapy for osteoporosis
nutrition - increase calcium and vitamin D
Exercise - weight bearing and resistance training
Smoking cessation
Limit alcohol consumption
sun exposure
Non pharm therapy for fall prevention
throw rugs assistive devices in bathrooms good lighting clear walking paths avoid slippery condiitons proper eye wear avoid medications affecting balance
Who gets pharm treatment for osteoporosis
postmenopausal females or males 50+ with:
- hip or vertebral fracture
- central BMD T score 3% or
2. 10 year probability of major osteoporotic fracture > 20%
Calcium better from diet or supplement
diet
MAx dose of calcium that can be absorbed per dose
600 mg elemental
