Osteoporosis Flashcards
What are some reasons for bones breaking?
- Suboptimal peak bone mass
- Reduced bone quality: reduced bone mineral (Ca2+), deteriorating architecture, change in crystal size and composition, abnormal collagen
What are some ways of optimising bone mass?
- Exercise
- Diet
- Regulating sex hormones
- Genetics
What does blue sclera of the eyeballs indicate?
Caused by the sclera being thin
It’s a common sign of osteogenesis imperfecta
What is a rheumatoid nodule?
It’s a subcutaneous mass filled with inflammatory tissue
It’s common in people with rheumatoid arthritis
What are some medical disorders that predispose people of osteoporosis?
Endocrine disorders:
- Thyrotoxicosis
- Hyperparathyroidism
- Pituitary disease
Nutritional deficiencies:
- Malabsorption conditions
- Eating disorders
- Alcoholism
Inflammatory conditions
Chronic respiratory disease
What is the FRAX risk calculator for?
It estimates the risk of having a hip or other major fracture in the next 10 years
What is a DEXA scan?
A bone density scan
How do Bisphosphonates work?
They inhibit osteoclast action by inhibiting an important enzyme
What do osteoclasts do?
Degrade bone for remodelling
What do osteoblasts do?
They build bone by synthesising the bone matrix
How must bisphosphonates be taken and why?
They need to be taken once a week in the morning before breakfast with a full glass of water standing up because they are very acidic and can cause severe damage Eg. contact stomatitis, oesophageal ulcers, osteonecrosis of the jaw (ONJ)
What is the function of Rank ligand?
It stimulates the osteoclasts
Name some drugs used to prevent fractures in osteoporosis
-Alendronate (weekly) Can be buffered (less acidic) or standard -Risendronate (weekly) -Zolendronate (IV annually) -Denosumab (subcutaneous 6 monthly) -Gonadal hormone replacement therapy -Calcium and vitamin D in the elderly
Name some drugs that encourage bone growth in osteoporosis
-Teriparatide (subcutaneous daily for 2 years)
-Romosozumab (intramuscular monthly for 1 year)
It increases bone growthy by increasing signalling
How is calcium absorbed by the body?
It must be first released into a soluble and ionised form for absorption via transcellular and paracellular transport. Vitamin D is needed for transcellular transport of calcium
The bioavailability of calcium varies between foods
Which nutrients increase the absorption of calcium?
Lactose and oligosaccharides
What are the effects of vitamin D deficiency?
Rickets in children
Osteoporosis in adults
Secondary hyperparathyroidism
What is vitamin K important for in bones?
It activates osteocalcin which builds and heals bone
What is Zinc important for in bones?
Important for bone metabolism
Name a indicator for a hip fracture in the blood
Under-gamma-carboxylated osteocalcin which is a marker for vitamin K statues and indicates hip fracture
What are the impacts of bad posture?
- Pressure on the vertebrae
- Increased risk of fall
- Causes muscle weakening
- Increases social problems like body image
Which type of fracture can be fatal and why?
Hip fractures are very dangerous because they result in many breaks at once which damages lots of the sacral blood vessels and nerves
95% are caused by falls
