Biochemical Disorders of Bone Flashcards
Osteoporosis is a ______________ defect of bone
Quantitative
How is osteoporosis defined?
- Reduced bone mineral density
- Increased bone porosity
(i.e. the bone is of normal quality, there is just less of it)
Osteoporosis can lead to what?
Fragility of bone and increased fracture risk
What is the term given to the intermediate stage on the progression to osteoporosis?
Osteopenia
(bone mineral density is lower than normal but not enough to be classified as osteoporosis)
Loss of bone mineral density is a ___________ process which generally begins to occur after the age of __
Normal
30
Which sex is affected more by osteoporosis and why?
Females
There is an increased osteoclastic response after the menopause as oestrogen is reduced and no longer provides a protective effect
How many types of primary osteoporosis exist?
2
What is type 1 osteoporosis?
Post-menopausal osteoporosis
Why does post-menopausal osteoporosis occur?
There is an increased osteoclastic response due to reduced oestrogen which usually counteracts this response
What are the risk factors for type 1 osteoporosis?
- Early menopause
- Genetics
- Alcohol abuse
- White caucasian
- Smoking
- Lack of exercise
- Poor diet
Which type of fractures are associated with type 1 osteoporosis?
- Colles’ fractures
- Vertebral insufficiency fractures
What is a Colles’ fracture?
A fracture involving the distal radius, where the fractures bone is bent backwards
This is associated with causing carpa tunnel syndrome by compressing the tunnel
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What is type 2 osteoporosis?
Osteoporosis of old age
What are the risk factors for type 2 osteoporosis?
- Female gender
- Genetics
- White caucasians
- Smoking
- Alcohol abuse
- Lack of exercise
- Poor diet
- Chronic disease
- Reduced sunlight exposure (low vitamin D)
Which type of fractures are most common in type 2 osteoporosis?
- Femoral neck fractures
- Vertebral fractures
Osteoporosis can occur secondary to which other conditions?
- Corticosteroid use
- Alcohol abuse
- Malnutrition
- Chronic disease (CKD, malignancy, RA)
- Endocrine disorders (Cushing’s, hyperthyroidism, hyperparathyroidism)
How is osteoporosis diagnosed?
DEXA bone scan
Serum calcium and phosphate are __________ in osteoporosis
Normal
What are the aims of treatments for osteoporosis?
To reduce disease progression
What are the possible pharmacological treatments for osteoporosis?
- Calcium supplements
- Vitamin D supplements
- Bisphosphonates
- Desunomab
- Strontium
- Zoledronic acid
- Intranasal calcitonin
- Raloxifene
- Hormone replacement therapy
Give three examples of bisphosphonates and what is the purpose of this drug class in relation to osetoporosis?
- Alendronate
- Risedronate
- Etidronate
They aim to reduce osteoclast activity
What does Desunomab do?
It is a monoclonal antibody which reduces osteoclast activtity
What does strontium do?
Increases osteoblastic replication and reduces osteoclastic activity
What is zoledronic acid and what is its function?
A once yearly IV bisphosphonate