Osteoporosis Flashcards
What is osteoporosis (OP)? What is it associated with?
- Chronic skeletal disorder of compromised bone
strength - Associated with low bone density (quantity) and bone deterioration (quality), leading to fragility fractures
What does bone strength depend on?
- Bone mass (measured as bone mass density = BMD)
- Bone microarchitecture
At what age does peak bone mass occur?
~ mid 30s
When does bone loss accelerate for women?
Menopause (due to loss of estrogen)
What is a spine compression/fragility fracture?
Loss of ≥ 25% of vertebral height w/ end plate disruption
What are 2 possible results of spine fragility fractures?
1) 6-9 inches height loss
2) Extreme spine curvature (kymphosis or dowager’s hump)
What are 8 consequences of fractures?
1) Increased incidence of additional fractures
2) Chronic pain
3) Immobility
4) Decreased QOL
5) Loss of independence
6) Institutionalization (rehab and long-term care)
7) Immense healthcare costs
8) Death (esp after hip or spine fracture)
Why has it been suggested that OP be referred to as bone attacks?
Bc ≤20% of women and ≤10% of men get tx to prevent further fragility fractures
How do fragility fractures occur?
- Spontaneously
- Coughing/sneezing
- Bending
- Hugging
- Minor traumas (for example, fall from: sitting, ≤ standing height, at ≤ walking speed, ≤ 3 stairs in height)
What are 3 common sites for fractures?
1) Hip
2) Spine
3) Wrist
(NOT feet, ankle, hands, cranio-facial)
How is BMD assessed?
Via Dual X-ray Absorptiometry at hip and spine
How does WHO classify OP?
Based on BMD (T-score ≤ -2.5)
What is T-score?
- How much a person’s peak bone mass deviates from normal young adult (usually 20-29 y/o)
- T-score units = standard deviation (-1 to 1 = normal)
What is Z-score?
Sex and age matched comparison of BMD
BMD does not determine fracture risk
BMD needs to be incorporated into risk calculator
Where is calcium stored in the body?
~99% stored in bones and teeth
1% stored in blood, muscle, other tissues
What regulates serum calcium levels?
- Calcitonin (increased calcitonin, decreased Ca)
- Parathyroid hormone, PTH (increased PTH, increased Ca)
What is the recommended amount of elemental Ca/day (for ≥ 50 y/o)?
1200 mg
Ca + Vitamin D supplements (can be dosed separately) insufficient to prevent fractures in pts with OP
Must be used in adjunct with OP meds
What are the best food sources of Ca?
- Milk products
- Fortified beverages
What is the recommended dose of Ca?
500 mg for max absorption
What are 2 Ca supplements?
1) Calcium carbonate
2) Calcium citrate: can be taken w/ or w/o meals
What are 2 issues with CaCO3?
- Must be taken with meal for best absorption (compared to calcium citrate, which can be taken with or w/o food)
- May be associated with GI issues
When is calcium citrate indicated?
- If pt is on PPI or H2 blocker
- If CaCO3 intolerable
What are 2 AEs of over-supplementation?
1) kidney stones
2) if supplementation taken w/o Vit D, increased MI risk (?)
What are 3 roles of Vitamin D in the body?
1) Helps body absorb and use Ca and P to build/maintain strong bones and teeth
2) Helps protect older adults against OP
3) Improves immune function
What are 3 food sources of Vit D?
1) Fatty fish
2) Egg yolks
3) Milk/fortified food and drinks (not standardized)
How is Vit D monitored in serum?
- 25(OH)D is monitored in serum bc it has a long half life
- It reflects total Vit D from food, supplements, and sun
What is the optimal 25(OH)D serum levels?
≥ 75 nmol/L
Why is there a high prevalence of Vit D deficiency in Canada?
- Sunscreen and clothing
- Northern latitude and seasons
- Age/skin pigmentation
- Most need supplements to meet recommended daily amounts*