Osteoporosis Flashcards
Osteoporosis
-disease characterized by low bone mass (density) & michroarchitectural deterioration leading to bone fragility & increased risk of dx
Prevalence of Osteoporosis
-most common bone disorder
-risk of hip fx doubles q5-6y incre in age from ages 65-85yo
-affecting 10M Americans; 8M are women
-1 in 2 women aged 50yo+ will sustain osteoporosis-related dx in their life
-prior low-trauma fx (fragility fx) is also a dx of osteoporosis regardless of DEXA; excludes fingers, toes, face, skull, or pathological or traumatic fxs
Postmeno Osteoporosis
-peak bone mass in most women reached at age 20yo
-genetic factors account for 50-85% of variance in bone BMD; lifestyle factors like nutrition & exercise contribute less
-accelerated bone loss at spine (largely comprised of trabecular bone) a/w menopause
-by age 80yo, women have lost about 30% of their peak bone mass
WHO definition of BMD
Normal: T-score >/= -1.0
Low Bone mass (osteopenia): T-score >/= -1.0 & -2.5
Osteoporosis: T-score </= -2.5
-based on white postmeno women
-T-scores only to be used for postmeno women
-Z-scores report BMD for similar age, sex, race premeno women
Osteoporosis: Ethnic Differences
-BMD differences exist btwn ethnicities
-black women have higher BMD than white & hispanic (independent of body wt)
-Asian descent have lower BMD than whites, but body wt may attenuate these differences
-white & hispanic women have highest rates of osteoporosis-related fx, black women having lowest rates
Osteoporosis management
-identify postmeno at risk for fx using DEXA & FRAX (online validated fx risk prediction tool)
-review fam hx of osteo/fxs
-dietary & lifestyle changes (smoking cessation, fall reduction, dietary ca+ intake)
-lab work up for secondary causes of osteo
-patients w osteo (by DEXA) or hx of low-trauma fx or high risk fx based on FRAX, rec for FDA-approved pharmacotherapy
RF captured in FRAX
-age
-sex
-weight & height (BMI)
-prior fragility dx
-parental hx of hip fx
-secondary causes of osteoporosis (DM type 1, vitamin D deficiency, malabsorption disorders, chronic inflammatory diseases, certain meds that affect bone loss)
-low femoral neck BMD (optional; FRAX valid wo BMD)
-RA
-current smoking
-etoh use >3units/day
Bone Health H&P
-assess lifestyle behaviors (exercise v sedentary)
-review medical, surgical, medications
-review ca+, vit D intake
-assess annually or when physical/mental status changes occur:
>height
>if >1.4in height loss from adult peak or 0.8 in prospective loss, refer for lateral spine imaging or vertebral dx assessment
>wt
>chronic back pain or kyphosis
>RF for bone loss
BMD testing recs
-all women >65yo
-postmeno aged <65yo if FRAX score for 10yr risk of major dx is >8.4% (avg fx risk for healthy 65yo)
-women postmeno or meno transition at high risk for fx based on clinical RF (low body wt <21 BMI, prior fx, high-risk med use, disease or condition a/w bone less)
-postmeno w hx of fragility fx
-anyone being considered for pharmacotherapy
-anyone treated, to monitor tx effect
-anyone receiving therapy in whom evidence of bone loss would lead to tx
Screening Techniques
-choose the lowest of 3 BMD scores: total hip, femoral neck, AP lumbar (must have at least 2 vertebrae)
-trabecular bone score: provides 2D grayscale image of spine microarchitecture, independently predicted fx risk, computer software available on select DEXA
Role of Bone Turnover Markers
-should not be used in clinical practice
-if needed, use of serum CTX (C-terminal of type 1 collagen via a fasting morning blood sample) may help monitor med compliance or evaluate appropriate bone turnover response during permitted “drug holidays”
Confirming Vertebral Fx
-measure pts >50yo on wall-mounted stadiometer yearly, check for postural changes, evaluate for back pain
-suspect vertebral fx in pt w height loss regardless of back pain; >1.5in from peak, or >0.8in from last height
-radiologic confirmation
-20% vertebral height loss (4mm heigh loss from baseline)
Identify Secondary Causes
-hyperthyroidism, hypercalciuria, certain drugs (AIs), calcium/vitamin D deficiency, RA, celiac disease, malabsorption diseases like Crohn’s, ulcerative colitis
-secondary work up includes lab & urine tests such as CBC, CMP, LFTs, phosphorus, TSH, parathyroid hormone, 24-hr urine calcium/creatinine collection: also serum protein electrophoresis, celiac panel, 24-hr urine cortisol, other specialized tests
Lifestyle Modifications
-maintain healthy weight
-obtain adequate vit D (600-800IU/d) & ca+ (1200mg/d); treat vit D def w higher dose
-participate in wt-bearing, resistance/wt-training, & balance/posture exercise
-avoid excessive etoh consumption (7-10 standard drinks/wk)
-do not smoke
-institute measure for falls prevention
-evaluate meds for AEs that block ca+ absorption (PPIs) or incr risk of falls (somnolence, dizziness)
Drug Therapy Indications
-hx of vertebral, hip, fragility, or low-trauma fx
-BMD values c/w osteoporosis
-10yr FRAX risk of major osteoporotic fx >20% or hip fx >3%
-in women on high-risk meds such as AIs or chronic glucocorticoids to prevent bone loss caused by those meds
