Osteoporosis Flashcards
What is osteoporosis?
a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk
What are the negative impacts of osteoporosis?
QoL impact of a fracture is high
significant contributor to mortality risk
What is fragility fracture/osteoporosis-related fracture?
occurs as a result of falling from a standing height or when force is applied to the bone judged to be insignificant to fracture a normal bone
Which sort of fractures are categorized as major osteoporotic fractures?
hip, vertebra, humerus and distal forearm
-hands, feet, and craniofacial bones are not
What is the most common bone disorder seen in clinical practice?
osteoporosis
What are the two types of bone?
cortical:
-80% of the weight of the adult skeleton
-dense, forms outer shell
cancellous (trabecular):
-20% of the weight of the adult skeleton
-porous, forms interior structures
What are the three types of bone cells?
osteoblasts
-builds bone through synthesis of collagen
-groups of osteoblast units create hydroxyapatite
osteoclasts
-reabsorbs bone
-necessary for homeostasis of acid-base, calcium & phosphate
osteocytes
-regulate rate of bone mineralization
Briefly describe the pathophysiology of osteoporosis.
once remodeling balance is -ve, BMD declines
advancing age causes many bone changes:
-oxidative stress
-osteoblast senescence
-autophagy declines
sex steroids play a role
osteocyte death accelerates with age
osteocyte death leads to:
-increased surface remodeling
-replacement with weaker mineralized connective tissue
-disruption in repair signaling
-decrease in bone vascularity
low Ca–>PTH release–>mobilization of Ca & PO4 from bone
=vit D activation: increased Ca, PO4, Mg absorption, decreased PTH, increased bone resorption
high Ca–>calcitonin release
=decreased absorption of Ca and PO4, Ca excretion, prevents bone resorption
What are the roles of calcium and vitamin D?
calcium: required for mineralization of bone
vitamin D: helps regulate calcium
When does bone mass peak?
3rd decade of life
What are the risk factors for osteoporosis?
race
age
sex
weight
small stature
calcium intake during growth
menopause
family history
secondary causes (drugs, conditions, lifestyle, history)
What are some medical conditions associated with osteoporosis?
oophorectomy
hypogonadism or premature menopause
hyperparathyroidism
hyperthyroidism
Cushings
multiple myeloma
malabsorption syndromes
chronic inflammatory diseases
other (COPD, T1DM, renal)
What are some drugs associated with osteoporosis?
androgen deprivation therapy
anticoagulants
SSRIs, SNRIs, lithium
antineoplastics
antiretrovirals
calcineurin inhibitors
antiepileptics
SGLT2i, TZDs
loop diuretics
glucocorticoids (>3mo/yr, 7.5mg/d)
Depo Provera
excess thyroid supp
excess vit A and retinoids
PPIs
What are some lifestyle factors associated with osteoporosis?
nutrition
caffeine
alcohol
smoking
exercise
sunshine
What are some risk factors for falls and fractures?
age-related
environmental hazards
drug falls (anti-HTN, psychotropics)
What is the presentation of osteoporosis?
no symptomatic manifestations until fracture occurs
unexplained pain & height loss may indicate vertebral fracture
vertebral fracture=most common
-many are silent
-then distal forearm and hip
What is diagnostic of osteoporosis?
vertebral compression fracture, hip fracture or > 1 fragility fracture over 50 years of age
-single fragility fracture warrants screening and monitoring
Differentiate osteoporosis and osteopenia.
osteoporosis: BMD T-score < -2.5 SD normal peak
osteopenia:BMD T-score -1 to -2.5 SD normal peak
Who should be screened for osteoporosis?
men and women over 50yrs
-screened + low risk: reassess in 5yrs
-moderate risk + no tx: reassess in 1-3yrs
What are the steps in assessing for osteoporosis and fracture risk?
- detailed history
- physical examination
- biochemical tests
- BMD in selected individuals
- use of risk assessment tools (CAROC, FRAX)
- vertebral imaging in selected individuals
What are some considerations when collecting a history for osteoporosis assessment?
identify risk factors for low BMD, falls, and fractures
ask about:
-acute/chronic back pain
-contributing disease
-meds
What are some things we are looking for during a physical examination for osteoporosis?
weight loss
-low body weight (<60kg)
->10% weight loss since age 25
height loss
-historical height loss (>6cm)
-measure height loss (>2cm)
Get-Up-and-Go-Test
What are the recommended biochemical tests for osteoporosis assessment?
calcium
phosphate
eGFR
TSH
25-OH-D
ALP
What is the most widely used and accurate tool for BMD testing?
dual-energy X-ray absorptiometry (DXA)
Describe DXA.
“total hip”, “femoral neck” and “lumbar spine”
should not be the sole indication for treatment
measured as SDs the persons BMD is above/below control
When does diagnosis with DXA become unreliable?
if < 50 yrs
-T score=adults > 50
-Z score=adults < 50
What are the limitations of DXA?
BMD does not measure bone loss since peak bone density achieved
measures bone quantity not quality
What are the indications for BMD testing?
postmenopausal women
age 50-64 with previous osteoporotic-related fracture or > 2 risk factors
age > 65 with 1 risk factor
age > 70
What are the two risk assessment tools available for osteoporosis?
CAROC
FRAX
True or false: treatment decisions can be made from the risk assessment tools
true
Describe the CAROC tool.
validated for postmenopausal women and men > 50yrs
easier to understand than T-score
basal risk category obtained from age, sex, and T-score at femoral neck
What are the three zones with the CAROC tool?
low=<10%
moderate=10-20%
high=>20%
fragility fracture (not vertebra or hip) after age 40 or recent prolonged steroid use shifts risk category higher
fragility fracture or vertebra or hip or > 1 fragility fracture=high risk
Describe the FRAX tool.
incorporates more risk factors than CAROC
computes 10yr probability of hip fracture AND major fracture
can be used without BMD
What is the preferred risk assessment tool according to the new osteoporosis guidelines?
FRAX
What are the caveats with the risk assessment tools?
for treatment naive patients only
cannot be used to monitor response to therapy
should not be applied to individuals younger than 50
does not reflect risk reduction with therapy
may underestimate risk with certain risk factors
When should we repeat BMD?
10yr fracture risk > 15% or on pharmacotherapy:
-3yrs
10yr fracture risk 10-15%:
-5yrs
10yr fracture risk <10%:
-5-10yrs
3yrs after stopping a bisphosphonate
What are the treatment goals for osteoporosis?
prevent fractures
prevent disability and loss of independence
preserve or improve BMD
reduce modifiable risk factors
What are the lifestyle modifications to prevent fractures?
exercise
fall prevention
other
-smoking cessation and reduce alcohol
reduce caffeine
calcium
vitamin D
What are the benefits of exercise on bone?
stimulates osteoblast activity
improves QOL, strength, pain, balance, physical function
clinical benefits:
-decreased fall risk
-decreased fracture risk
-better maintenance of BMD
Which forms of exercise should be prioritized in osteoporosis?
balance, functional, and resistance training > twice weekly
-increase difficulty, pace, frequency, volume over time
What is balance exercise?
exercises that challenge aspects of balance
-shifting weight
-reduce base of support
-balance while moving
What is functional exercise?
exercises that improve ability to perform everyday tasks
What is resistance training?
exercises where major muscle groups work against resistance
What are some strategies to prevent falls?
patient education
home safety assessments
hip protectors
bars, canes, walkers
remove tripping hazards
improve balance and strength
avoid drugs associated with increased fall risk
What are some “other” lifestyle modifications to make for osteoporosis?
smoking cessation
-1 pack yr history=~10% BMD reduction
-negates protective effects of HRT for women
-BMD may return to non-smoker lvl within 10yrs
reduce alcohol intake
avoid excess caffeine
->4 cups/day may lower BMD 4%
-no fracture risk increase found
What are the RDAs for calcium?
men:
-51-70yrs: 1000mg/d
->70yrs: 1200mg/d
women:
->50yrs: 1200mg/d
What are the recommendations for calcium supplementation for a patient who has adequate dietary intake?
supplement not recommended to prevent fractures
-balanced diet: supp will have no to little effect on fractures
What are the available salts of calcium?
calcium carbonate: 40% elemental
calcium citrate: 20% elemental
calcium lactate: 13% elemental
calcium gluconate: 9% elemental
How is calcium best taken?
calc carb best taken with food (acidity to dissolve)
calcium citrate if on PPI or want to take it without food
consuming <550mg elemental calcium at one time maximizes absorption
What are the drug interactions of calcium?
PPIs (decrease absorption)
decreased absorption of ciprofloxacin, iron, protease inhibitors, tetracycline, thyroid meds
What are the adverse effects of calcium when exceeding 2000mg/d?
nephrolithiasis
CV disease
dyspepsia
constipation
dietary sources preferred over supps as excess supp can have adverse effects
What is the quick estimation method for calcium intake?
automatically give 300mg for Ca in all dietary sources
give extra 300mg for foods high in Ca
What is the RDA for vitamin D?
men and women:
-<70yrs: 600IU vitamin D/d
->70yrs: 800IU vitamin D/d
HC recommends a supp. of 400IU/d to meet RDA
What are the dietary sources of vitamin D?
few food sources:
-fatty fish (salmon, trout)
-fortified foods (milk)
-eggs
sun exposure