Pathophysiology of Osteoporosis Exam 1

Question 1

Risk Factors for Osteoporosis and Osteoporotic Fractures

Answer 1

• Low bone mineral density (BMD)
• Advanced age >65
• Female sex
• Race / ethnicity (AA have lower risk)
• History of previous fragility fracture
• Osteoporotic fracture in a first-degree relative
• Postmenopausal
• Heavy alcohol consumption
• Cigarette smoking
• Low body weight (under 127 lbs)
• Predisposing medical conditions (ex. pts w/ RA)
• Predisposing medications

Question 2

Medications Associated with for Osteoporosis and Osteoporotic Fractures

Answer 2

• Anticonvulsants
• Antiretrovirals
• Chemotherapy
• Glucocorticoids (e.g. > 5mg/d of prednisone for > 3 months)
• Heparin and LMWHs
• Medroxyprogesterone acetate injectable contraceptive
• Selective serotonin reuptake inhibitors
• Proton pump inhibitors
• Thiazolidinediones

Question 3

What are the four steps in bone remodeling?

Answer 3

• Resorption
• Reversal
• Formation
• Quiescence (or Activation)

Question 4

Resorption

Answer 4

Bone breakdown facilitated by osteoclast cells that resorb (dissolve) bone.

Question 5

Reversal

Answer 5

Occurs when evacuation is complete and is the process of osteoclast undergoing apoptosis or moving to a new section.

Question 6

Formation

Answer 6

Bone building process facilitated by osteoblast cells. Osteoblast ultimately become lining cells or become part of bone as osteocytes.

Question 7

Quiescence (or Activation)

Answer 7

Rest period following bone formation.

Question 8

Role of calcium in bone physiology

Answer 8

chief mineral component of the skeleton and is essential to the development and function of bone

Question 9

Role of VitD in bone physiology

Answer 9

• modulate calcium and phosphate homeostasis
• Vitamin D undergoes hepatic conversion; then PTH stimulates its renal conversion to the active form of vitamin D, calcitriol
• calcitriol is promotes intestinal calcium absorption

Question 10

Role of parathyroid hormone (PTH) in bone physiology

Answer 10

modulate calcium and phosphate homeostasis

Question 11

Role of RANKL in bone physiology

Answer 11

major stimulus for hematopoietic stem cell differentiation necessary for development of mature osteoclasts

Question 12

What are the categories of bone mass / osteoporosis from the World Health Organization (WHO)?

Answer 12

• Normal bone mass
• Low bone mass (AKA osteopenia)
• Osteoporosis
• Severe osteoporosis

Question 13

What are the WHO values for normal bone mass?

Answer 13

T-score of -1 or higher

Question 14

What are the WHO values for low bone mass (osteopenia)?

Answer 14

T-score between -1 and -2.5

Question 15

What are the WHO values for osteoporosis?

Answer 15

T-score of -2.5 or lower

Question 16

What are the WHO values for severe osteoporosis?

Answer 16

T-score of -2.5 or lower PLUS history of fragility fracture

Question 17

Signs of Osteoporosis

Answer 17

• Deformity (i.e. dowager’s hump)
• shortened stature
• fracture

Question 18

Symptoms of Osteoporosis

Answer 18

• Pain
• immobility
• depression
• low self-esteem

Question 19

Risk factors for falls

Answer 19

• Prior fall / prone to falls
• Impaired vision or hearing
• Physical disability
• Environmental hazards
• Orthostatic hypotension
• Cognitive impairment
• Medications

Question 20

Medications associated with falls

Answer 20

• Antidepressants
• Antihistamines
• Antihypertensives
• Antipsychotics
• Benzodiazepines
• Digoxin
• Diuretics
• Narcotic analgesics
• Laxatives

Question 21

Which patients should undergo BMD testing?

Answer 21

• All women > 65 years of age
• Postmenopausal women < 65 years of age at increased risk for osteoporosis as determined by a formal risk assessment tool (i.e. SCORE, OST, or FRAX without BMD)
• Women and men with history of fragility fracture
• Some groups recommend screening for all men > 70 years of age and those 50-69 years of age at increased risk
• May consider re-testing every 2 years