Osteoporosis

1
Osteoporosis
2
Osteoporosis Scope of the Problem

• Osteoporosis is characterized by low bone mass
  and micro architectural deterioration of bone
  tissue, leading to bone fragility and an increase
  risk of fracture
• 10 million individuals already have osteoporosis

.
3
Osteoporosis Scope of the Problem

• 18 million more have low bone mass
• One out of two women and one in eight men over 50
  will have an OP related fracture in their
  lifetime
• OP is responsible for more than 1.5 million
  fractures annually

.
4
OP by the Numbers Continued

• 2 million American men have OP, 80,000 men suffer
  a hip fracture an up to one third of these men
  die within one year
• Estimated national direct expenditures (hospital
  and nursing homes) for OP related fractures 13.8
  billion annually

5
Osteoporosis Definition

• A chronic, progressive condition associated with
  deterioration of bone tissue that results in low
  bone mass. As the condition progresses bone
  fragility increases leading to increased risk of
  fracture.
• Osteopenia is bone that is not as dense as normal
  bone and is a precursor to osteoporosis.

6
Osteoporosis Importance

• OP is a major health concern for 2 reasons.
• Osteoporotic fractures, most commonly of the
  vertebrae, femur, and wrist are associated with
  increased morbidity and mortality.
• As the fraction of elderly individuals in the
  population increases, OP will become more
  prevalent.

7
Osteoporosis Prevalence

• Based on Bone Mineral Density data
• 6 to 7 million non-institutionalized older U.S.
  women have osteoporosis
• 12-17 million additional women have osteopenia
  which also increases risk of fracture

8
Osteoporosis Diagnosis

• Suspected by presence of risk factors.
• Bone Mineral Density determination.
• Like hypertension and atherosclerosis,
  osteoporosis can be defined by an intermediate
  outcomein this case, low bone mineral density or
  BMD.

9
Risk Factors in Osteoporosis

• Nonmodifiable
• Personal history of fracture as an adult
• History of fracture in first degree relative.
• Caucasian race
• Advanced Age
• Female sex
• Dementia
• Poor Health/frailty

• Potentially Modifiable
• Smoking
• Low Body Weight (lt127 lbs)
• Estrogen deficiency
• Early Menopause (lt45 yr) or
• Prolonged amenorrhea
• Excess alcohol intake
• Sedentary lifestyle
• Low calcium intake
• Inadequate physical activity
• Poor health, poor eyesight and recurrent falls.

10
Bone Mineral Density Determination in Osteoporosis

• Dual X-Ray absorption (DEXA) is most widely used
  due to excellent precision and accuracy, low
  radiation exposure, reasonable cost and length of
  time required to scan a patient.
• Sites most commonly assessed
• Lumbar spine
• Non-dominant hip

11
BMD Details

• BMD measurement at any anatomical site can
  predict risk of fracture at a distant site.
  However the measurement of a given site is most
  accurate for its own risk of fracture.

12
BMD Details Two Additional Measures

• Z score
• Compares the BMD measured to the BMD of
  individuals who are at peak bone mass. Usually at
  age 35 years
• Predicts the patients risk of fracture
• Aka young adult

• T score
• Compares the BMD measured with the BMD or age
  matched peers
• Indicates if factors other than age may be
  affecting the patients BMD
• Aka age matched

13
BMD Assessment Controls

• Both Z-score and T-score are expressed as
  standard deviations above and below the mean and
  are controlled for weight, ethnic origin and
  gender.

14
Fracture Risk

• For each 1 standard deviation below the mean of
  the Z score the risk of fracture nearly doubles
• Scores within one SD considered normal
• Scores between 1 SD and 2-2.5 SD below the mean
  considered osteopenia
• Scores more than 2-2.5 SD below the mean are
  considered osteoporosis

15
Prevention

• To understand strategies for OP prevention a
  person must first understand the biology of bone
  acquisition and bone loss
• There is a balance between bone deposition by
  cells called osteoblasts and and bone resorption
  by cells called osteoclasts

16
Normal Bone

• When resorption and deposition are in balance
  there is no net change in the amount of bone
  present

17
Osteoporotic Bone

• After menopause occurs the balance is shifted in
  favor of increased bone resorption and a loss of
  bone mass results

18
Comparison of Normal and Osteoporotic Bone

• Normal Bone

• Osteoporotic Bone

19
Factors in Prevention of Osteoporosis

• Nutrition
• Level of exercise
• Medical conditions
• Genetic makeup
• Smoking
• Alcohol

20
Nutrition

• Calcium is an essential component of many
  processes in the body and bone serves as a
  calcium reservoir
• Parathyroid hormone maintains calcium in the
  blood at the expense of bone integrity if dietary
  calcium is inadequate

21
Vitamin D

• Plays an important role in calcium absorption and
  bone metabolism
• The active metabolite can be synthesized in the
  skin with the influence of sunlight, but adequate
  supplementation is a must for individuals who are
  institutionalized or live in geographic areas
  where there is inadequate sun exposure

22
Weight Bearing Exercise Negative Potential

• Exercise in premenopausal women who exercise to a
  point where menstrual function is lost (exercise
  induced amenorrhea) a low estrogen state exists
  and accelerated bone loss can occur as in after
  menopause
• Exercise has potential for trauma for
  postmenopausal women who have low bone density

23
Weight Bearing Exercise Positive Aspects

• Weight bearing exercise helps maintain competent
  bone mass
• Sedentary lifestyle contributes to osteoporosis

24
Medical Conditions

• Excess thyroid hormone can cause bone loss
• Hyperthyroidism or over medicated hypothyroidism
• Steroid therapy can cause bone loss by direct
  effect on bone, and by suppressing pituitary
  function and leading to decreased ovarian
  function and low estrogen states
• Rheumatologic, renal, pulmonary and allergic
  diseases

25
Smoking

• Leads to low BMD
• Possible toxic effects on ovary decreasing
  estrogen levels
• Smoking increases rate at which estrogens are
  cleared from the body

26
Alcohol Abuse

• Those who drink heavily have low bone mineral
  density compared to nondrinkers and moderate
  drinkers
• Possible direct toxic effect on bone
• Heavy drinkers often have nutritional
  deficiencies

27
Treatment of Osteoporosis

• Hormone replacement therapy
• Biphosphonates
• Calcitonin
• All three treatments work to decrease resorption
  of bone

28
Hormone Replacement Therapy

• Prevents decrease in BMD
• HRT eliminates hot flashes associated with
  menopause and can also help with other low
  estrogen related conditions
• Most importantly HRT has beneficial effect on
  cholesterol
• May treat some causes of urinary incontinence
• May enhance collagen content of skin

29
HRT Problems

• Breast cancer risk?
• Uterine stimulation may cause resumption of
  menses or spotting. Progesterone also required
  if uterus is present
• Breast tenderness
• Progesterone alone may help with hot flashes, but
  recent studies show it does not increase bone
  mass!!

30
Evista (Raloxifene HCl)

• A new option for prevention of postmenopausal
  Osteoporosis
• Selective Estrogen Receptor Modulator (SERM)

31
Evista (Raloxifene HCl)

• Selective Estrogen Receptor Modulator (SERM)
• Binds to estrogen receptor
• Estrogen-like effects in some tissue
• Estrogen-blocking effects in other tissue

32
Evista Molecule With Two Active Binding Sites

• Estrogen Agonist
• Increases Bone Mineral Density
• Decreases total cholesterol and LDL cholesterol

• Estrogen Antagonist
• Binds to sites in uterus and breast
• No uterine stimulation
• No bleeding
• No uterine cancer risk
• No need for provera (progesterone)
• No breast stimulation
• No breast tenderness

33
Evista As an Antiresorptive Agent in Bone

• Preserves Bone
• Increases BMD (less than estrogens 0.625mg/day)
• Normal bone quality
• Effects on fracture risk appear encouraging
  especially for vertebral fractures

34
Bone Remodeling

• After menopause Bone resorption exceeds formation
• Evista suppresses resorption
• Reduces osteoclast number and activity
• Reduces number of resorption sites
• As a result reduces bone turnover and improves
  balance between resorption and formation

35
Evista Adverse Events

• Hot flashes and leg cramps
• Risk of deep vein thrombosis similar to that of
  traditional HRT, which is quite rare
• Contraindicated in patients who
• Are or may become pregnant
• History of venous thromboembolic events
• Are allergic to Evista

36
Biophosphonates

• Structurally related pyrophosphate which plays an
  important role in bone metabolism
• Fosamax (alendronate) and Didronel (etidronate)
  are the two most common
• BMD increases seen with Fosamax likely the
  largest compared to all other current treatment
  options

37
Biophosphonates Problems

• Didronel if taken daily can lead to bone
  demineralization so it is dosed every 3 months
  for 14 days
• Stomach upset, esophageal irritation and strict
  dosing instructions complicate therapy
• Not to be used in patients with gastrointestinal
  disorders

38
Calcitonin

• Available in nasal spray
• Has analgesic effect on back pain from
  osteoporosis
• Effective in slowing progression of osteoporosis
• Can not be used if individual is allergic to fish
  products

39
Combination of Therapies

• No current studies available
• Literature suggests considering combination
  therapy when HRT alone fails to stem progression
  of osteoporosis

40
Additional Information

• www.osteo.org
• http//odp.od.nih.gov (NIH)

41
Osteoporosis

• Questions?

42
Topics

• If you have any medically related topics you
  would like presented please let us know.

43
The End

• October 13, 1999