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PHAR 255 Exam 1 > Osteo > Flashcards

Osteo Flashcards

1
Q

Define osteoporosis

A

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

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2
Q

Osteoporosis QOL, Mortality Risk

A

QoL impact of a fracture very high
Significant contributor to mortality risk
About 1/3 of elderly population will require treatment

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3
Q

What is a fragility fracture?

A

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

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4
Q

Where are fragility fractures most seen?

A

Fractures of the hip, vertebra, humerus and distal forearm are categorized as major osteoporotic fractures, whereas fractures of the hands, feed and craniofacial bones are not

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5
Q

What are the two types of bone?

A

Cortical
80% of the weight of the adult skeleton
Dense, forms outer shell

Cancellous (trabecular)
20% of weight of the adult skeleton
Porous, forms interior structures

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6
Q

What are the types of bone cells?

A

Osteoblasts
Builds bone through synthesis of collagen matrix
Groups of osteoblast units (osteoids) create hydroxyapatite

Osteoclasts
Reabsorbs bone
Necessary for homeostasis of acid-base, calcium & phosphate

Osteocytes
Regulate rate of bone mineralization

A balance between osteoblast/ clast activity results in continuous remodelling

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7
Q

When does BMD start to decline?

A

Once remodeling balance is negative, BMD begins to decline

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8
Q

How does age affect bone?

A

Advancing age causes many bone changes:

Oxidative stress (free radicals, low grade inflammation, increase in bone resorption and apoptosis of bone)
Osteoblast senescence (halt production)
Autophagy declines (important method for providing quality control over bone cells – bone building becomes less robust)

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9
Q

What steroids play a role and hpw?

A

Sex steroids play an important role (deficiency leads to more clast than blast activity)

Estrogen (most important determinant for bone formation)
Androgens

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10
Q

Other role of hormones

A

Parathyroid  Calcitonin (Balance; PTH steals from bone and takes it to the blood)
Glucocorticoid hormones

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11
Q

Vitamin Roles

A

Role of calcium and vitamin D
Calcium required for mineralization of bone
Vitamin D helps regulate calcium

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12
Q

Pathophysiology of osteoporosis

A
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13
Q

What accelerates with age?

A

Osteocyte dearh

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14
Q

Describe bone loss as we age

A

Bone mass peaks in 3rd decade of life
After age 35  in cortical bone by ~0.5% per year

Additional 2-3% loss per year during menopause which gradually decreases over the next 8-10 years

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15
Q

Most common place of fracture

A

Vertebral

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16
Q

Risk factors?

A

Race - Caucasion and asian
Calcium Intake during growth
Age
Menopause - Decreased estorgen
Family History
Sex
Small Staure
Weight - Low body weight

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17
Q

Med COnditions leading to osteo

A

Oophorectomy
Hypogonadism (need androgens and estrogens – e.g. delayed puberty) or premature menopause (<45 y)
Hyperparathyroidism
Hyperthyroidism
Cushing’s syndrome – Excess cortisol
Multiple myeloma
Malabsorption syndromes – Decreased Ca2+ and Vit D e.g. Chrons, celiacs, bypass surgery
Chronic inflammatory diseases
e.g., rheumatoid arthritis, lupus
Other – T1DM, Renal Disease, People who receive transplant, COPD

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18
Q

Anticoags

A

Main one: Heparin – long term use 5-10% of bone mineral loss (>6 months); LMWH less risk; warfarin is uncertain

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19
Q

Antidepress

A

Antidepressants – SSRIs, SNRIs, lithium
 Decreased osteoblastic activity; situation where we would not stop if well controlled but acknowledge the risk

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20
Q

Anti-epileptics

A

Antiepileptics – phenytoin carbamazepine, valproic acid
 Increase breakdown of vitamin Dand falls

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21
Q

Anti-retorvirals:

A

Antiretrovirals – tenofovir, protease inhibitors
- Decrease osteoblastic activity and osteoblasts

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22
Q

Calineurin Inhibitors

A

Calcineurin inhibitors – tacrolimus, cyclosporine
 Increased osteoclastic activity

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23
Q

Diabetes Meds

A

Diabetes medications – Thiazolidinediones, SGLT2 inhibitors
 SGLT2-I – Canagliflozin decreased risk in bone mineral density; not associated with fracture risk

24
Q

Glucoocorticoid Tx

A

(>3 months cummul/yr; avg dose 5 mg/d prednisone or equivalent)
WE DO CARE HERE (HOW MUCH AND HOW LONG): may have someone on prophylactic medication such as bisphosphonates
Lots of mechanisms; take it into consideration

25
Q

Loop Diuretics

A

 Increase Ca2+ loss and cause negative balance of blood bone Ca2+ (Small effect)

26
Q

B.C.

A

Medroxyprogesterone acetate

BMD can decrease 5% with long term use; failure to achieve peak BMD when younger; fracture risk is unknown though; no evidence to limit duration
BMD loss is reversible upon D/C – keep up with exercise, Vit D, Ca2+

27
Q

PPI’s

A

Calcium needs acidity to absorb properly; however, extent is unknown on BMD

28
Q

Thyroid SUpplements

A

ncreases osteoclast activity compared to osteoblast activity

29
Q

Vitamin A

A

More fracture risk than compared to not; do not double multivitamin to get more of one thing as get more of all

30
Q

Lifestyle fx

A

Nutrition

Exercise

Alcohol

Smoking - inhibits estrogen

Caffeine - increase Ca2+ output

Sunshine

31
Q

Falls fracture risk

A

Age-related fractures
Previous fractures (more fractures = more risk)

Enviromental hazards (e.g. tripping)

Drug-falls
Psychotropics

Antihypertensives

32
Q

presnetation of Osteo

A

No symptomatic manifestations until fracture occurs (many people without symptoms might not think they have it)

Unexplained pain and height loss may indicate vertebral fracture

33
Q

Are fractures often knowwn? Most common?

A

Vertebral fracture is the most common, then hip and distal forearm
Many vertebral fractures are “silent”

34
Q

Diagnosis of osteo

A

Vertebral compression fracture, hip fracture, or >1 fragility fracture over 50 years of age is diagnostic

Single fragility fracture warrants immediate testing and monitoring

35
Q

In diagnosis, differentiate between?

A

May also differentiate between osteoporosis and osteopenia (Dexa-scan)

Osteoporosis: BMD T-score <-2.5 SD normal peak
Osteopenia: BMD T-score -1 to -2.5 SD normal peak

36
Q

Screening

A

Men and women >50 should begin routine assessment of risk factors for osteoporosis and fracture

If screened and low risk, reassess in 5 years
If moderate risk (and not treating), reassess in 1-3 years

37
Q

In a patient history, ask about…..

A

Medications: Corticosteroid usage

38
Q

Physical Exam Criteria

A
39
Q

Weight and height crteria in osteo

A

Weight
Low body weight (< 60 kg)
Major weight loss (> 10% of weight at age 25)

Height
Historical height loss (> 6 cm)
Measured height loss (> 2 cm)

40
Q

Recommended tests

A

Calcium, corrected for albumin
Phosphate
Creatinine (eGFR)
Alkaline phosphatase (bone turnover marker)
Thyroid stimulating hormone (TSH)
25-hydroxy vitamin D (25-OH-D) – Contentious
Should be measured after 3-4 months of adequate supplementation and should not be repeated if an optimal level ≥75 nmol/L is achieved.

Serum protein electrophoresis for patients with vertebral fractures

41
Q

Bone Mineral Testing Example. What does it measure?

A

Dual-energy X-ray Absorptiometry (DXA)

Most accurate and widely used tool

“total hip”, “femoral neck” and “lumbar spine (L1-L4)”

42
Q

Measurements of DXA

A

Measured as number of standard deviations (SD) the person’s BMD is above or below a control value

Should not be used as sole indication for treatment

Unreliable for diagnosis if <50
T-score = Used for adults ≥ 50
Z-score = Used for adults < 50

43
Q

DLmitations of DXA

A

BMD does not measure loss since peak bone density achieved (number at that time)

Measures bone quantity not quality (can be differences between the two)

44
Q

Indications for DXA

A

Postmenopausal women and men:

Age 50 – 64 with a previous osteoporotic-related fracture or > 2 clinical risk factors for fracture

Age > 65 with 1 clinical risk factor
See risk factors on next slide

Age > 70

45
Q

Risk factors (DXA Indication)for fracture

A

Previous fracture, after age 40 years
Glucocorticoids (> 3 mo in the last year, prednisone dose > 5mg /d)
Falls, >or = 2 in the last year
Body mass index < 20 kg/m2
Secondary osteoporosis (see next slide)
Current smoking
Alcohol > or =3 drinks /d

People get frisky before s* anyones c*

46
Q

Secondary causes of osteoporosis

A

Drugs:
Glucocorticoids, aromatase inhibitors, anticonvulsants, GnRH agonists and antagonists, Androgen-deprivation agents, Cancer chemotherapy, immunosuppressants
Endocrine disorders:
Hyperthyroidism, hyperthyroidism, hypercortisolism/Cushing’s, diabetes, prolonged premature hypogonism, acromegaly
GI and nutritional disorders:
gastric surgery, bariatric surgery, malabsorption syndrome, vit D/calcium def
Rheumatologic disorders
RA, SLE
Genetic disorders
Osteogenesis imperfecta
Other disorders strongly associated with rapid bone loss or fracture
COPD, transplant. Paget’s

47
Q

Risk Assesment Tools

A

Estimates 10-year absolute risk

CAROC: Canadian Association of Radiologists and Osteoporosis Canada
FRAX: Fracture Risk Assessment Tool developed by the World Health Organization

48
Q

Treatment of osteo is decoided from:

A

Treatment decisions can be made from FRAXa nd CAROC

49
Q

Caroc Validated For: What is risk calculated from?

A

Validated for postmenopausal women and men > 50

Easier to understand than T-score

Basal risk category is obtained from age, sex, and T-score at the femoral neck

50
Q

CAROC is straified into —— zones. IMPORTANT CRITERIA?

A

Stratified into three zones

Fragility fracture (not vertebra or hip) after age 40, or recent prolonged steroid use shifts risk category higher

Fragility fracture of vertebra or hip, or >1 fragility fracture = high risk

51
Q

CAROC Uses what to determine score?

A
52
Q

advanatge of FRAC?

A

Incorporates more factors than CAROC:

Sex
Age
BMI
Prior fracture
Parenteral hip fracture
Prolonged corticosteroid use
RA or other secondary causes
Current smoking or alcohol intake

53
Q

Preferred method for osteo guidelines?

A

Canadian specific FRAX is the preferred tool in the new guidelines

54
Q

Caveats of absolute risk tools

A

Calculate risk for treatment-naïve patients only (not on tx – no longer validated if on tx)

Cannot be used to monitor response to therapy

Models should not be applied to individuals younger than 50

May underestimate risk in the presence of specific factors: e.g., recency of fractures, recurrent falls, other comorbidities or very low BMD at the lumbar spine and total hip sites

55
Q

When should BMD density using risk calculation testing be repeated?

A

May repeat earlier if secondary causes of osteoporosis, new fracture or new clinical risk factors associated with rapid bone loss

Repeat BMD 3 years after stopping bisphosphonate

PHAR 255 Exam 1 (8 decks)

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