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Flashcards in Osteoporosis Deck (31):
1

Osteoporosis

Reduction in the strength of bone that leads to increased risk of fractures

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World Health Organization (WHO) for Osteoporosis

A bone density that falls 2.5 standard deviations (SD) below the mean for young healthy adults of the same sex (T score of -2.5)
Postmenopausal women who fall b/w -1.0 and -2.5 also have low bone density and are at increased risk of developing osteoporosis
(>50% of fxs among postmenopausal women occur in this group)

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Epidemiology for Osteoporosis

Most common bone disease
Osteoporosis causes around 2 million fractures/yr in US
As many as 8 million women and 2 million men have osteoporosis and an additional 18 million have osteopenia (T score -2.5)
Morbidity and indirect mortality rates are very high
Primarily due to complications of the treatment of fractures

Fractures of distal radius increase in frequency before age 50 and plateau by age 60 w/ only a modest age-related increase thereafter

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Complications of Osteoporosis

Wrist Fractures

Hip fractures
Associated with a high incidence of DVT and PE (20-50%)
Mortality rate b/w 5-20% during the 1st year after surgery

Vertebral fractures are relatively asymptomatic
Associated w/ a long-term morbidity and a slight increase in mortality rates primarily due to pulmonary disease.
Multiple fractures lead to loss of height, kyphosis and secondary pain and discomfort in the back.
Thoracic fractures can be associated with restrictive lung disease

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Primary type of Osteoporosis

Type I: Postmenopausal (rapid bone loss w/in 6 years of menopause, mainly trabecular bone)
Type II: Senile (men and women >75yr of age), slow progression, both cortical and trabecular bone

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Secondary type of Osteoporosis

Sex hormone deficiency (hypogonadism, prolactinoma, orchiectomy for tx of prostate cancer)
Hormone excess (hyperthyroidism, hyperparathyroidism, corticosteroids)
Increased bone resorption/formation ratio: immobilization, space flight, long term heparin, cancers such as MM, lymphoma, breast cancer
Multifactorial (renal failure, anorexia, athletic amenorrhea, ETOH use d/o)

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Risk Factors of Osteoporosis Non Modifiable

Women (postmenopausal/low estrogen)
White race
Advanced age
Personal hx of fracture as an adult
History of fracture in a first degree relative
Dementia

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Risk Factors of Osteoporosis Potentially Modifiable

Low body weight
Current cigarette smoking
ETOH abuse
Low calcium intake
Vitamin D deficiency
Inadequate physical activity/immobility

9

Risk Factors of Osteoporosis Chronic Disease

Rheumatologic and autoimmune d/o
Endocrine: hypogonadal states, anorexia, DM, Cushings syndrome, hyperthyroidism
GI disorders: Celiac, gastric bypass, Crohn’s, malabsorption
Hematology/Oncology: Multiple Myeloma, lymphoma, leukemia
CNS: Epilepsy, Muscular Sclerosis (MS), Dementia, Parkinsons Dz, poor eyesight

10

Risk Factors of Osteoporosis Medications

Glucocorticoids (most common), anticonvulsants, immunosuppressants(cyclosporine), cytotoxic drugs, Aromatase inhibitors, long term Heparin, Lithium, hormonal therapies, long term PPIs, high dose inhaled steroids in elderly

11

Pathophysiology for Normal Growth

Skeleton increases in size by linear growth and by apposition of new bone tissue on the outer surface of the cortex called modeling (allows the long bones to adapt and shape to the stresses placed on them).

During puberty, there is increased sex hormone production that is required for skeletal maturation

In young adults resorbed bone is replaced by an equal amount of new bone (bone mass remains constant after peak bone mass is achieved in adulthood)- equal balance

12

Pathophysiology for Adults

Bone remodeling (2 primary functions)
Repair microdamage w/in the skeleton to maintain skeletal strength
To supply calcium from the skeleton to maintain normal serum calcium
**Regulated by: estrogen, androgens, vitamin D, Parathyroid hormone (PTH) as well as numerous growth factors


At age 30-45yr: Resorption exceeds formation
Exaggerated in women after menopause
Excessive bone loss can occur if there is an increase in osteoclastic activity and/or a decrease in osteoblastic activity

13

Signs and Symptoms for Osteoporosis

Usually asymptomatic unless the patient sustains a fracture
Gradual height loss
Increased kyphosis of thoracic spine (Dowager hump) with a secondary protuberant abdomen
Pain (bone pain or deformities may result from fractures)

14

Diagnosis for Osteoporosis

Made clinically in the setting of a fragility fracture regardless of T-score
In postmenopausal women and men>50 w/ no fragility fracture diagnosed by bone density testing

15

Labs for Osteoporosis

Primarily used to rule out secondary causes:
CBC (anemia, Multiple Myeloma)
Calcium
elevated hyperparathyroidism
low Vitamin D def or GI malabsorption
Phosphorus (elevated in renal failure)
Vitamin D level (goal is >30ng/mL)
Albumin (nutrition status)
Alkaline Phosphatase
Serum protein electrophoresis- MM
Creatinine (kidney function)
TSH (hyperthyroidism)
PTH
Elevated hyperparathyroidism
Low suggests malignancy

24-h urinary calcium excretion
300mg/24h indicates hypercalciuria

In men total testosterone and liver transaminases

16

Imaging for Osteoporosis

Dual-energy X-ray absorptiometry (DEXA)- gold standard test
Measures bone density w/ minimal radiation exposure

Looks primarily at the spine and hip, though portable scans evaluate the heel, forearm or fingers)

Results are reported using T scores and Z scores

T scores:
Compares the individual results to those of a healthy 30 year old of the same race and sex
T score of -2.5 is considered osteopenia (precursor to osteoporosis)

Z scores compare individual results to those of an age-matched healthy person of the same race and sex
not used to diagnose osteoporosis

17

Approved Testing Guidelines

For postmenopausal women and men >50 years old:
Measure height annually

DEXA scan:
All women >65yr
All men >70yr
Postmenopausal women 3months
Primary hyperparathyroidism
Monitoring response to an FDA approved medication for osteoporosis

18

Osteoporosis Treatment- Treat Underlying Fx

Hip fractures: typically require ORIF followed by rehabilitation and pain mgmt
Vertebral fractures: acute pain mgmt if symptomatic, vertebroplasty/kyphoplasty (supplies immediate pain relief), chronic pain mgmt (d/t muscles, ligaments and tendons)
Wrist fractures: may or may not require pinning, ORIF or manual reduction, acute pain mgmt

19

Osteoporosis Treatment- reduce underlying modifiable risk factors

d/c medications if possible
smoking cessation
alcohol abuse treatment
environmental safety in the home (eliminating throw rugs, move exposed wires/cords, improve lighting at night to eliminate fall risks)
treat impaired vision
Specialized supervision and care for patients with dementia, etc.

20

Improve Nutrition for Osteoporosis Treatment

Calcium supplementation: normal levels 8.5-10.5mg/dL
Men and Women age 19-50y1000mg/d
Men and Women age 51y and over 1200mg/d


Vitamin D: Target level is >30ng/mL
Synthesized in skin under the influence of heat and UV light
Given in doses of 800IU-2,000IU/day
Vitamin D dosing for treating deficiency is different than for replacement.
High doses must be used to replenish stores. For vitamin D deficient adults (levels <20) 50,000 IU of vitamin D2 or D3 can be given once weekly for six to eight weeks for replenishment.
Once a deficiency has been corrected, the patient is on maintenance doses

21

Weight Bearing Exercise for Osteoporosis Treatment

Prevents bone loss, but does not necessarily increase bone mass
Improves coordination, strength, and balance and therefore reduces the risk of falling
Needs to be consistent (at least 3 days/week)

22

Pharmacological Treatment for Osteoporosis

Bisphosphonates---1st line Tx
Estrogen
Selective estrogen receptor modulators (SERM’s)-----
1st line though not as effective as Bisphosphonate
Calcitonin-----Rarely used
PTH
Testosterone

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Bisphosphonates MOA

- inhibit osteoclast-induced bone resorption
- Increases bone density and reduce the incidence of both vertebral and nonvertebral fractures
- Prevents corticosteroid induced osteoporosis

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Examples of Bisphosphonates

Alendronate (Fosamax) 70mg po once/week (reduce v and nv fxs)
Risendronate (Actonel) 35mg po once/week (reduce v and nv fxs)
Ibandronate sodium (Boniva) 150mg po once/month (reduces v fxs only)
Parenteral agents: used if can’t tolerate oral agent
Zoledronic acid (once/year)
Pamidronate (q3-6 months)

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Side Effects of Bisphosphonates

Osteonecrosis of jaw, esophagitis, esophageal cancer

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Treatment length for Bisphosphonates

½ life is 10 years; therefore it is now recommended to d/c after 5 years of treatment

27

Estrogen

Reduces bone turnover, prevents bone loss and causes small increases in bone mass of the spine, hip and total body
Not recommended as first line tx of osteoporosis, best used as prevention
Potential for serious long term side effects (increased risk of CV events, breast cancer, strokes, endometrial hyperplasia/bleeding, DVT/PE) therefore no longer 1st line therapy

28

Selective estrogen receptor modulators (SERMS)

Used in prevention of osteoporosis in postmenopausal women
ex. Raloxifene (Evista) 60mg/d po
Reduces risk of vertebral fx’s only
Reduces risk of invasive breast cancer, does not cause endometrial hyperplasia, bleeding or uterine cancer
Similar to estrogen, increases risk of DVT/PE

29

Calcitonin

Role is unclear, produces small increases in bone mass of the spine
Nasal spray of calcitonin-salmon (Miacalcin) 2200U/mL in 2mL bottle
One puff QD (200IU
Less nausea and flushing than parenteral route
SE: rhinitis and epistaxis
Has analgesic affects on bone pain from fractures
Reduces # of new vertebral fractures only; therefore not used in prevention nor is it potent enough to prevent bone loss in early postmenopausal women

30

PTH MOA

Approved for both men and women w/ established osteoporosis
MOA: Works on osteoblasts. Favors bone formation over bone resorption, produces an increase in bone tissue and restores the microarchitecture
Ex. Teriparatide (Forteo, Parathar)- analog of PTH

31

Testosterone

Used in hypogonadal men to prevent osteoporosis