Osteoporosis

Question 1

Define Osteoporosis

Answer 1

Imbalance of bone resorption and bone formation or defective achievement of peak bone mass leading to reduced bone density and increased risk of fracture.

Question 2

What are the RF for osteoporosis?

Answer 2

Reduced peak bone density due to e.g. lack of exercise
F due to post-menopausal oestrogen deficiency- bone resorption exceeds formation. Early menopause partic imp
age (due to age-related bone loss, bone formation reduces in amount whereas resorption stays same)
Genetics
Heavy alcohol use
Smoking
Imobilization

Question 3

What is the aetiology of Osteoporosis?

Answer 3

Hypogonadism (both T and O deficiency lead to uncoupling of resorption and formation and increased resorption)
Corticosteroid use (prolonged and over 7.5mg) bc steroids inhibit osteoblast activity and cause their apoptosis
HyperPTH induces rapid bone turnover and bone formation cannot keep pace
HyperThyroid induces rapid bone turnover and bone formation cannot keep pace
Cushings disease causes the inhibition of osteoblast activity and cause their apoptosis
Anorexia- Ca2+ deficiency, weight loss, hypogonadism
Malabsorption- Ca and vitamin D deficiency and consequent HyperPTH
Inflammatory conditions- proinflamm cytokines increase clast activity and reduce blast activity

Question 4

What is the pathophys of osteoporosis?

Answer 4

Osteoporosis can occur because of a defect in attaining
peak bone mass and/or because of accelerated bone
loss e.g. due to inhibited osteoblast activity or increased osteoclast activity.

Question 5

How would you investigate suspected osteoporosis?

Answer 5

PC: fracture, kyphosis, height loss
FRAX: prediction tool for likelihood of osteoporotic fracture
DEXA scan- calcium in bone attenuates the passage of X-ray beams in proportion to the amount of mineral present. Osteoporosis is diagnosed when the T-score value falls to −2.5 or below.
Hx including falls
Examination- endocrine disease, ca, inflammatory disease
Bloods: FBC, U+E, LFT, TFT, ESR, Ig’s, VitD levels, PTH

Question 6

How would you manage osteoporosis?

Answer 6

1. Stop smoking
2. Reduce alcohol intake
3. Dietary Ca2+ intake
4. Exercise
5. Risk of Falls/ recurrent falls- Referral to falls MDT
6. Hip protectors
7. Bisphosphonates (Alendronate/ Risedronate)- Bisphosphonates inhibit bone resorption by binding to
   hydroxyapatite crystals on the bone surface. Improves the balance of formation and resorption increasing bone density. - not well absorbed GIT therefore take on empty stomach. Can cause upper GI upset therefore sit up while and for a while after taking.
8. Ca and Vitamin D are particularly effective for elderly patients.
9. Strontium ranelate
10. PTH injections usually reserved for severe osteoporosis due to cost .