Osteoporosis Flashcards
(28 cards)
Gender and Bone Mass: Stats
-women experience greater bone loss in early postmenopausal years (continues at a gradual rate)
-women have lower peak density (these factors combine so women reach “fracture threshold” earlier than men)
-men lose about a 1/3 less bone mass compared to women over a life time
-in women, at around age 30: bone reabsorbed by osteoclasts > bone formed by osteoblasts
Osteoporosis: Definition
bone mineral density that is 2.5 standard deviations below peak bone mass
How do you measure bone mineral density?
DEXA scan
Results reported in a T-score
Classification for Normal Bone Mineral Density
normal
T-score is -1 or greater
Classification for Osteopenia
low bone mass (“poor bone”)
T-score is between -1 and -2.5
Classification for Osteoporosis
literally means “porous bone”
T-score is ≤ -2.5
Classification for Severe Osteoporosis
osteoporosis WITH a history of a fragility fracture
T-score is ≤ -2.5
Osteopenia: Definition
thinning of the trabecular matrix of the bone before osteoporosis
T-score between -1 and -2.5
Osteoporosis: Definition
“porous bone”
characterized by: low bone density and structural deterioration of the bone
-usually bones in the
hips, vertebrae, and
wrists (trabecular
bones)
osteoporosis is used when ACTUAL BREAKS in trabecular matrix have occurred
common, serious disease
Osteoporosis: Characteristics (4)
-low bone mass
-micro-architectural deterioration
-increase in bone fragility
-susceptibility to fracture high
Osteoporosis: Major Risk Factors (9)
-aging
-female (esp. postmenopausal)
-Caucasian
-history of fracture as adult
-family history
-body weight < 127lbs
-smoking
-alcohol use
-long-term corticosteroid therapy & immunosuppressive drugs
Osteoporosis: Minor Risk Factors (7)
-thin, small frame
-lack of weight bearing exercises
-lack of Ca and/or Vitamin D
-eating disorders
-gastric bypass surgery
-lack of estrogen/testosterone
-excessive caffeine consumption
Osteoclasts have the function to _____________
disrupt the old bone tissue
A hyperactivity of osteoclasts is one of the causes of __________
of the onset of osteoporosis
Osteoblasts have the function to ____________
produce new bone tissue
A proper balance between osteoclasts and osteoblasts is the basis for _______________
a normal bone density
Osteoporosis: Pathogenesis
increased bone reabsorption (osteoclast activity increased); decrease bone formations (osteoblast activity decreased);
-problem can be: failure to make new bone (osteoblasts); too much bone reabsorption (osteoclasts); or both
Osteoporosis: Early CM
NONE
Osteoporosis: Late CM (4)
fractures
pain
loss of height
stooped posture (Kyphosis)
Osteoporosis: Complication
Hip fracture
-osteoporotic hip fractures linked to increased risk of mortality (2.8-4x GREATER RISK of death)
-more common in those greater than 65
-more common in women
-most common location: proximal third of the femur
Hip Fracture: Clinical Presentation (5)
-sudden onset of hip pain before OR after a FALL
-inability to walk
-severe groin pain
-tenderness
-affected leg is externally rotated and shortened
Osteoporosis: Pharmacotherapy: Goal, Prevention, & Treatment
Goal: reduce fractures
Primary prevention:
-Ca (diet and
supplement- 1200 to
2000mg/day)
-Vitamin D (diet and
supplement- 800 to
1000 IU/day)
Treatment:
-promote bone
formation
-decrease bone
reabsorption (MOST
common)
Osteoporosis: Classes of Pharm (3)
biphosphonates
selective estrogen receptor modulators
hormone therapy: Calcitonin
Aldendronate (Fosamax): Indication, Class, and MOA
-osteoporosis
-reduces fractures by 50
-biphosphonate
-binds permanently to surfaces of bones to inhibit osteoclast activity
