HD 7- Metabolic bone disorders Flashcards
Relationship between calcium and PTH?
Low Ca = Increases PTH
High Ca = decreases PTH
Hyper parathyroidism- bones gradually deteriorate and release Ca, very high blood calcium levels
Parathyroid gland detects low blood calcium levels and releases PTH hormone, which stimulates release of calcium from bones.
How is vit D3 from the sun stored in the body?
Stored in the liver as 25 vit-D3
Activates in kidney to 1,25-D3
Specific scan for osteoporosis?
DEXA
Consequences of vitamin D deficiency?
- In adults (bones finished growing) causes osteomalacia.
* In children (bones still growing) causes rickets.
Key features of rickets?
Poor diet indicated in pot belly
Swollen bones at epiphyses = champagne glass epiphyses
Fuzzy appearance
Deformed ribs
Key features of osteomalacia?
Bone pain, muscular weakness, malaise, rarely tetany
Treatment for vitamin D deficiency?
Vitamin replacement orally
Key features of Pagets disease?
Disease of unknown aetiology causing uncoordinated bone re-modelling.
Enlarged skull. Hearing aid (potentially aggravated by Paget’s disease). Fuzzy and thickened appearance of the skull.
Pain, deformity, increased fracture risk, compression of nerves- deafness
Treatment of Pagets disease?
Bisphosphonates- inhibit osteoclastic activity and prevent bone resorption
Alendronic/risedronate acid is most common treatment
Key features of osteoporosis?
Generalised skeletal disorder with reduced bone density impaired structure and increased risk of fracture.
Pagets is more localisedCommon, increases with age, women > men. More common post menopausal as reduced oestrogen.
Treatment of osteoporosis?
Bisphosphonates- (low dose) Alendronate or risedronate orally weekly
What is a major side effect of bisphosphonate therapy?
BRONJ (Osteonecrosis of the Jaw)
