Mar 28 Bone Health - Osteoporosis

Question 1

Bone composition (3 things)

Answer 1

– 50% mineral crystals (i.e. calcium
phosphate)
– 50% protein (collagen)
– Trabecular (quicker turnover aka breaks down and rebuilds more quickly) and cortical

Question 2

Bone is alive:

2 ways bones heal themselves:

Answer 2

Bone is constantly broken down and rebuilt — this is called the (re)modeling cycle.

Bone modeling happens mostly in childhood and teens to help bones grow.

Bone remodeling happens throughout life to keep bones strong and repair damage.

Question 3

In a constant state of turnover (resorption and formation): (4 things)

Answer 3

• Osteoblasts – bone forming/building cells
• Osteoclasts – bone resorbing cells
• Remodeling cycle starts with resorption
• Balance between resorption and formation = bone mass, Issue when these processes are “uncoupled”

Question 4

Bone Mass Across the Lifespan: (2 things)

Answer 4

Lifestyle practices when young affect peak bone mass development. Diet and exercise influence 20-40% of adult peak bone mass.

Question 5

Osteoporosis Canada says:

Answer 5

“pediatric disease with geriatric consequences”

Question 6

What is Osteoporosis?
(2 things)

Answer 6

Osteoporosis is a skeletal disorder characterised by:

Compromised bone strength
* Density and microarchitecture

Predisposition to an increased risk of fracture
* i.e. fragility fractures (following minor trauma)

Question 7

Low Bone Mass - Osteoporosis: (2 things)

Diagnosis:

Answer 7

In osteoporosis, bones are thinned due to mineral loss and are vulnerable to fracture.

• Affects trabecular bone more as regions with high trabecular bone = fracture sites E.g. Wrist, femoral neck, vertebral bodies

Diagnosis:
DEXA scans to assess risk by comparison to healthy young adults
* A T-score of -2.5 or lower (like -2.6, -3.0, etc.) indicates osteoporosis, which means bones are significantly weaker and more prone to fractures.

Question 8

Osteoporosis - DXA

2 main clinical sites for osteoporosis diagnosis.:

Answer 8

• Lumbar spine
• Femoral neck

Question 9

OVERALL risk of Osteoporosis depends on:(2 things)

Answer 9

OVERALL risk depends on:
(1) starting peak bone mass (BMD)
(2) rate at which it is lost

Question 10

Do men get Osteoporosis? (2 things)

Answer 10

Yes, but less often than women
* Men have greater bone mass to start (bigger bodies, more muscle, more testosterone) and don’t go through menopause (hormonal fluctuations)

Question 11

Risk Factors for Osteoporosis (4 things)

Answer 11

Diet and Exercise
* inadequate intakes of protein, key vitamins and minerals (vit D, calcium)
* lack of weight bearing/impact exercise to stimulate bone formation

Age and Sex:
* bone loss starts to occur ~35 yrs (rate of 0.3-0.5%/yr)
* greater risk to women because women have lower peak bone mass and go through hormonal changes

Genetics:
* important determinants of bone density, bone size, bone turnover rates (racial differences).

Smoking and Alcohol:
* affect ovarian function, hormone production, nutrient intakes.

Question 12

Common Symptoms of Osteoporosis (Name 5)

Answer 12

• Pain in bones and lower back
• Height loss (~1.5 inches every 10 yrs after menopause)
• Fatigue and Night cramps in legs and feet
• A forward bending of cervical/thoracic spine (dowager’s
  hump, kyphosis)
• Non-traumatic/fragility fractures (osteoporosis causes 90%
  of fractures after age 65).

Question 13

Common Fragility Fractures: Name 3

Answer 13

Vertebral body compression fractures:
* Loss of height, forward hump

Colles’ wrist fracture:
* Distal radius fracture – break a fall with outstretched hands

Hip fractures:
* At femoral neck, intertrochanteric line, proximal shaft

Question 14

Incidence of Osteoporotic Fracture by Age Group. Which fracture is most common

Answer 14

Hip, vertebrae, wrist

Question 15

Relative risk of mortality following fractures:

Answer 15

Hip and spine fractures = increased mortality

Question 16

PREVENTING AND TREATING OSTEOPOROSIS (Name 2)

Answer 16

1. Calcium, Vitamin D, and Protein
2. Exercise and Medication

Question 17

Diet - Calcium

RDA for calcium:

– Children (4-8 yrs):
– Youth/adolescents (9-18 yrs):
– Young adults (F 19-50, M 19-70 yrs):
– older adults (F 51+, M 71+ yrs):

Answer 17

RDA for calcium
– Children (4-8 yrs): 1000mg/d; ensure enough for bone growth
– Youth/adolescents (9-18 yrs): 1300 mg/d; ensure enough for bone growth
– Young adults (F 19-50, M 19-70 yrs): 1000 mg/d; maintain bone mass and prevent loss
– older adults (F 51+, M 71+ yrs): 1200 mg/d; prevent bones loss and Osteoporosis

Question 18

Diet - Vitamin D: (3 things)

RDA for Vitamin D:
<70y: IU/d or μg/d;
≥70y: IU/d or μg/d

Examples of Vit D: (2 things)

Answer 18

Vitamin D:
* Risk for deficiency in Canada…..
* OC recommends that all Canadian
adults take a vitamin D supplement
(specifically, D3 or cholecalciferol)
year-round.
* Essential for the absorption of calcium

RDA for Vitamin D:
<70y: 600 IU/d or 15 μg/d; ≥70y: 800 IU/d or 20 μg/d

Examples:
* Fatty fish, egg yolks, fortified
milk,
* liver, margarine, juices, sun exposure (UVA/UVB)

Question 19

Diet - Protein and Dairy Products:

Dairy/Milk products: (4 things)

Answer 19

Adequate supply of amino acids is essential for bone.

Dairy/Milk products:
* High in protein
* Most common dietary sources of calcium
* Mandatory fortification with vitamin D in Canada (milk only)
* Contain other micronutrients (Mg, Zn, P, K, B12,Vit A), more per unit energy than any other typical food

Question 20

Are Canadians getting enough Bone Supporting Nutrients?

Answer 20

Protein intake: Adequate.

Vitamin D: Not enough, especially for those not taking supplements.

Calcium: Many are falling short, especially supplement users whose intake has declined.