Lecture 8: Osteoporosis Flashcards
What is osteoporosis?
- Low bone mass
- Microarchitectural disruption
- Skeletal fragility
Decreased bone quality or quantity.
When does osteoporosis affect women usually?
Starting around age 50
What are the 3 primary bone cells?
- Osteocytes
- Osteoblasts (B for builders)
- Osteoclasts (C for cut calcium)
What hormone is the primary mediator of calcium utilizing osteoclasts?
PTH
What exactly does estrogen do for bones?
Inhibition of osteoclasts
Where is trabeculae found?
- End of long bones
- Vertebrae
- Pelvis
- SKull
Also known as cancellous bone
When are the two general times to have osteoporosis?
- Postmenopausal (loss of bone mass)
- Adolescence (poor acquisition)
Primary cause of osteoporosis
Old age
RFs for Primary osteoporosis
- Caucasian/white
- Smoking
- Malnutrition (vit D/calcium)
- Decreased physical activity
RFs for secondary osteoporosis (drugs)
- Steroids
- VPA
- Heparin
- Depo-Provera
- Aromatase Inhibitors
- Cyclosporine
- Antacids
- Lithium
- Methotrexate
How much is chronic steroid use?
> 5mg Prednisone QD or equivalent for > 3 months
RFs for secondary osteoporosis (Diseases)
- Hyper PTH
- Hyperthyroidism
- Liver dz/alcoholics
- CKD
- Hypogonadism
- Cushings
- Malignancy
- Diabetes
- Immobility caused by dz
What could be a S/S of osteoporosis?
- Pathologic fx (compression vertebrae, hip, distal radius: colle’s)
- Loss of vertebral ht > 1.5 cm (upper L/T, shortening, kyphosis)
- Back pain w or w/o fx
Most back pain is NOT osteoporosis!
What are the USPSTF recommendations for osteoporosis screening?
- 65+ females
- High risk females under 65
Males is an I for insufficient, but everyone else says screen over 70.
Both are B
What T score corresponds to osteoporosis?
T < -2.5
Always use worst score to diagnose
What T score corresponds to osteopenia?
-2.4 < T < -1.0
What are DEXA T-scores compared to?
A 30 year old
What do DEXA Z-scores compare to?
Peer of equal age and gender
Not used for osteoporosis diagnosis
What does a significantly low Z-score suggest?
Concerning for secondary osteoporosis
Normal aging would have a minimal Z-score.
What is the other way to diagnose osteoporosis without a DEXA scan?
Fragility fx
If occurs with mild trauma
What can XR show for someone that is osteoporotic?
Can show demineralization, primarily in the axial skeleton
What is a FRAX score?
10-year likelihood of osteoporotic or hip fx.
When should you consider tx based off a FRAX score?
- Osteoporotic fx risk >= 20%
- Hip fx risk >= 3%
What kind of exercise increases osteoblast activity?
Weight bearing
Walking 1hr/ week is amazing! 20% reduction in risk of hip fx
What are the lifestyle modifications for osteoporosis and osteopenia?
- Exercise
- Smoking cessation
- ETOH moderation
- Fall prevention
2/d/males, 1/d/females max
What mineral supplementation is indicated for osteoporosis/osteopenia?
- Vit D replacement (at least 800 IU, preferably D3)
- If labs < 20, high dose 50k IU for 3-6 months then daily supp
- Ca replacement via calcium citrate. Can also use calcium carbonate but must take w food and cant use PPi with it.
Generally, you can get up to a level of 100, and toxicity is 150.
Avoid the annual bolus of 500k
What is the concern with ordering a Vit D test?
Not a normal screening test.
What are the ways to order a Vit D test and get insurance to pay for it?
- CKD 3 or higher
- Cirrhosis
- Hypo/hypercalcemia
- Hypercalciuria
- Hypervitaminosis D
- Parathyroid disorders
- Malabsorptive states
- Obstructive jaundice
- Osteomalacia
How much calcium intake is sufficient daily?
1200mg
Aim for 50% from food, since dairy has 300mg per serving.
Which calcium formulation is not affected by food or PPI use?
Calcium citrate
When is calcium supplementation indicated?
Low serum calcium or diet is insufficient
When do we use bisphosphonates?
Osteoporosis/penia with + FRAX
What is the patient education associated with bisphosphonates?
- 8oz of water first thing in the morning (no other food or water for 30 mins)
- Do not recline for 30mins to prevent reflux
- D/C if reflux symptoms occur
What is the primary SE to discuss with bisphonates and teeth?
Osteonecrosis of the jaw
Who should not use bisphosphonates?
- eGFR < 35
- Significant GI disorders
- Can’t sit up for 30-60 mins post ingestion
- Use IV zoledronic acid for other CIs besides kidney dz
How long is a drug holiday usually for bisphosphonates?
1 year
What is the advantage of denosumab injections over bisphosphonates?
No drug holiday, no CKD CI
Usually expensive af though
What is the last resort drug for osteoporosis/osteopenia with + FRAX?
Estradiol
Olny for women
Who might SERMs be preferred in for osteoporosis/osteopenia + FRAX?
Those with breast cancer risk
Used for people that also need breast cancer risk reduction + osteo
When is a PTH analog used? (Romosozumab)
- Osteoporosis/penia + FRAX
- Corrected vit D and calcium beforehand
- Consider use during bisphosphonate drug holiday
When do you get a repeat DEXA scan after starting pharmacotherapy?
2 years
When is referral to endocrinology for osteoporosis indicated?
- Premenopausal or men < 50
- Hx of fragility fx + normal DEXA
- Failed tx
- Can’t take normal tx
- Needs advanced therapy
What is osteogenesis imperfecta?
Inherited CT Disorder causing brittle bones.
What are the primary manifestations of osteogenesis imperfecta?
- Eye sclera: Blue/gray eyes
- Hearing loss
- Weak joints
- Soft bones
- Dentinogenesis imperfecta: discolored teeth + softness
What does osteogenesis imperfecta affect in terms of connective tissue?
Collagen 1
What are the 4 main types of osteogenesis imperfecta?
- Type 1: Mild (early osteoporosis)
- Type 2: Lethal (Will die immediately pretty much)
- Type 3: Severe (Short, frequent fx, triangle face)
- Type 4: Moderate (blue/gray eyes)
NOT IN ORDER!!
What might imaging show for osteogenesis imperfecta?
- Bowing
- Low bone density
What do you consider first in a child presenting with multiple fx?
Abuse
What are the two main distinctive signs of osteogenesis imperfecta?
- Blue eyes
- Hearing loss
Generally, how do you tx osteogenesis imperfecta?
- Combo PT/exercise
- IV bisphosphonates
- Supplemental GH for ht
- All depend on type