Symposia: Osteoporosis, Nutrition and Fragility Fracture Flashcards
1
Q
What causes people to break their bone?
- specific biological factors
A
- Bone strength is reduced
- Suboptimal peak bone mass
- Reduced bone quality
- Reduced bone Mineral ( Calcium )
- Deteriorating architecture
- Change in crystal size & composition
- Abnormal collagen
- Falls
2
Q
What factors can increase peak bone mass?
A
- Excercise
- Diet
- Sex hormones
- oestrogen deficiency –> osteoporosis
3
Q
What is Osteogenesis Imperfecta?
A
- a genetic defect where collagen (the protein that is responsible for bone structure) is missing, reduced or of low quality, so is not enough to support the minerals in the bone.
4
Q
What factors need to be considered in the history/ examination when considering fracture risks in older people?
A
- Age
- Previous Fracture
- Lightweight ( BMI < 18 )
- Family History
- Smoking
- Alcohol
- Medical Disorders
5
Q
What Medical disorders increase fracture risks?
A
- Osteogenesis imperfecta
- underproduction of collagen
- Cushing’s Syndrome
- treatment with Glucocorticoids/ steroids
- those with Inflammatory conditions
- Rheumatoid nodules
- Rheumatoid arthritis
- Prostate cancer - treatment with Androgen Deprivation Therapy
- low levels of testosterone reduces bone density similar to women going through menopause
- Chronic respiratory disease - treatment with steriods and reduced physical activity
6
Q
What nutritional factors impact bone health?
A
- Cows milk—source of calcium, magnesium, Vitamin D, protein and fat - good ‘bone’ food.
- Soya milk—bioavailability of calcium requires a higher level of fortification than that naturally seen in cows milk. Bioavailability may be compromised in some products.
- Balance of magnesium and calcium important—excess calcium depletes magnesium.
- Protein - diets high in protein can lead to a reduction of calcium but studies
- fractures neck of the Femur indicates improved bone healing in diets with high protein intake. Meta-analysis suggests no benefits from plant sources
- Vitamin D
- PUFA
- Gluten intolerance- gliadin and phytate are linked to reduced calcium absorption
- Phytate creates insoluble complexes with calcium
- Oxalate also inhibits bioavailability
7
Q
How can bone health be managed in osteoporosis?
A
-
Calcium—benefit seen in children in the short term.
- Postmenopausal women no effect on bone density but an effect on bone loss.
- Should be supplemented with Vit D +ve result
-
Vitamin K effect on osteocalcin, protein involved in bone mineralisation, enhances ability to bind calcium
- having a good microbiome in the colon benefits the activity
- Sodium—reduces intake in diey. causes increased calcium urinary loss seen when sodium intake high
- Phyto oestrogens - under investigation, some benefit seen where habitual intakes are high (regularly take soy products
- Strontium—stable strontium in low doses has been shown to increase bone formation and decreases done resorption
- EFA’s ALA [Omega 3] and LA [Omega 6] provide substrates for eicosanoids—prostaglandins, leukotrienes and thromboxanes. Dietary ratio affects bone formation and resorption. Omega 3 (alpha linolenic acid) reduces bone resorpion. Omega 6 (Linoleic acid ) increases bone resorption
8
Q
What is a clear physical sign of vertebral fractures?
A
- having a curved spine
- not often diagnosed presents as chronic back pain
9
Q
What are the clinically relevant sites that are scanned during a DEXA scan?
A
- Lumbar spine (L1-L4)
- Hip
- Forearm (hyper[arathyroidism, non-diagnostic spine or hip)
10
Q
What do BMD measurements from DEXA scans indicate about the bone health of a patient?
A
- For post-menopausal women and men over 50 WHO:
- T-score:
- Normal =equal or greater than -1
- Osteopenia=T score between -1 and -2.5
- Osteoporosis= T score equal to or below -2.5.
- Z score of < -2.0 means BMD is lower than it should be for someone age matched.
- For diagnostic purposes the lowest score should be used (any of total spine, total hip, NOF or total forearm).
11
Q
What is the traditional diagnosis of Osteoporosis? What measurements are taken?
A
- DEXA (dual-energy X-ray absorptiometry) scan - it uses low dose X-rays to measure bone mass per area (g/cm2)
- osteoporosis is diagnosed when T-score is -2.5 SD below the Bone Mineral Density (BMD) of a young healthy adult
- a Z-score can also be measured which is the SD between the measured BMD and that of someone of the same age
12
Q
What factors are used to generate the FRAX tool? (12)
A
- Age
- Sex
- Weight
- Height
- Previous fracture
- Parent Fractured Hip
- Current Smoking
- Glucocorticoids
- Rheumatoid arthritis
- Secondary Osteoporosis
- Alcohol 3 or more units/day
- Femoral neck BMD (g/cm2)
13
Q
What are the Bone Health Assessment Tools in the UK?
A
- FRAX score
- uses the femoral neck BMD on DEXA with clinical risk factors to calculate the 10yr probability of a major osteoporotic fracture or of hip fracture
- Q Fracture Risk Calculator
- Estimates the 1-10 year cumulative incidence of hip or major osteoporotic fracture
14
Q
What significance does the site of a fracture have?
A
- All fragility fractures increase future fracture risk independent of BMD - but some more than others.
- Fractures of the hip and spine carry a higher risk for recurrent fracture than fractures of the distal radius.
- vertebral fractures have a 5-fold increased risk of fracture in the year following
15
Q
What algorithm is used to assess absolute risk using a FRAX
(flow chart pathway)
A
- High risk → treat immediately
- Intermediate risk → DEXA scan reassess probability
- Low → monitor
16
Q
What does a Trabecular Bone score indicate
A
- High TBS → strong, fracture-resistant microarchitecture
- Low TBS → weak, fracture-prone microarchitecture
→ TBS decreases with age from ~45 years, can be used to compute FRAX score adjusted for TBS which s more accurate
