17f. MSK - Osteoporosis Flashcards
What is osteoporosis?
Low bone mass
Deterioration of bone tissue
Signs and symptoms of osteoporosis
Asymptomatic until fracture occurs
Common fracture locations in osteoporosis
Vertebrae
Hip
Distal radius
What is bone remodelling?
Bone resorption and bone formation
What do osteoclasts do in bone remodelling?
Dissolve minerals and protein in bone
What do osteoblasts do in bone remodelling?
Create a protein matrix of collagen
Remineralisation of bone
What substances can affect the bone remodelling process?
PTH
Oestrogen
Vit D
Corticosteroids
What is osteoporosis the result of?
Not enough osteoblast bone formation to compensate for osteoclast bone resorption
Causes and risk factors for osteoporosis
Increasing age
Female/post-menopause
Low body weight
Dairy products
High red meat
Nutrient deficiencies
Carbonated beverages
Caffeine
Alcohol
Smoking
Inactivity
Hypochlorhydria
Inflammation
Drugs
Gut dysbiosis
Other diseases
Why is increasing age a risk factor for osteoporosis?
Bone mass peaks at 25 years
Why is being post-menopausal a risk factor for osteoporosis?
Oestrogen deficient
Oestrogen inhibits OC formation
Why is low body weight a risk factor for osteoporosis?
Reduced mechanical stress from weight load
Lower aromatisation of androgens to oestrogens
Why is high red meat a risk factor for osteoporosis?
Acid-forming
(due to high methionine content)
Why are carbonated beverages a risk factor for osteoporosis?
High acid load due to phosphoric acid
Why are alcohol and caffeine risk factors for osteoporosis?
Decrease intestinal Ca absorption
Deficiencies in which vitamins are risk factors for osteoporosis?
D
Ca
Mg
Why is Ca needed for bone?
Bone architecture
Why is smoking a risk factor for osteoporosis?
Upregulates MMP which break down collage
Nicotine binds to osteoblasts promoting cell death
Why is inactivity a risk factor for osteoporosis?
Mechanical forces stimulate osteoblasts
Why is hypochlorhydria a risk factor for osteoporosis?
HCl is needed to ionise Ca to be absorbed by the gut
Why is inflammaiton a risk factor for osteoporosis?
High hsCRP levels are associated with bone mineral density
Inflammatory cytokines promote osteoclast activity
Why are drugs a risk factor for osteoporosis?
Corticosteroids promote osteoclast activity
Why is gut dysbiosis a risk factor for osteoporosis?
Intestinal bacteria needed for K2 synthesis
SCFAs regulate the differentiation of osteoclasts and inhibit bone resorption
Some microbes promote mineral absorption
Examples of other diseases that are a risk factor for osteoporosis
Cushing’s (high cortisol)
Coeliac (malabsorption)
