Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine Year 1 - Semester 2 - Part 2 > Osteoporosis > Flashcards

Osteoporosis Flashcards

1
Q

Function of osteoprogenitor cells

A

Stem cell population, gives rise to osteoblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Function of osteoblasts

A

Responsible for bone formation, cover the surface of bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are osteocytes ?

A

Mature bone cells - embedded in lacunae and are relatively inactive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Function of osteocytes

A

Maintain bone matrix through cell-cell communication and influence bone remodelling.

Mechanosensing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are osteoclasts ?

A

Multi-nucleated, derived from haematopoetic cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Function of osteoclasts

A

In response to mechanical stresses and physiological demands, they resorb bone matrix by demineralisation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Age 0-25

A

Bone gain

Resorption < Formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Age 25-35

A

Bone Mass Stable

Resorption = Formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Age >35

A

Bone Loss

Resorption > Formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is bone mass related to ?

A

Age

Biological Sex
(female - bone loss due to menopause)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe bone loss due to menopause

A

Hormonal changes associated with menopause.

Increased activity of osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Who does osteoporosis affect ?

A

~ 3 million people in the UK

1 in 3 women
(predominantly due to menopausal shift & regulation of osteoblasts activity)

1 in 12 men
(due to progressive decline in function)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Causes of osteoporosis

A

Decreased size of osteons

Thinning of trabeculae

Enlargement of Haversian and marrow spaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

State the classifications of osteoporosis

A

Type 1 - post menopausal
Type 2 - age related in those over 75

Disuse osteoporosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe Type 1- Post menopausal osteoporosis

A

Affects mainly cancellous (trabecular) bone

Vertebral and distal radius fracture is common

Related to loss of oestrogen

F:M= 6:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Type 1 - post menopausal osteoporosis related to ?

A

Loss of oestrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does Type 1 - post menopausal osteoporosis affect ?

A

Affects mainly cancellous (trabecular) bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe Type 2- Age related in those over 75

A

Affects cancellous and cortical bone

Is related to poor calcium absorption

Hip and Pelvic fractures common

F:M= 2:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is Type 2 - age related osteoporosis in those over 75 related to ?

A

Poor calcium absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does Type 2 - age related osteoporosis in those over 75 affect ?

A

Affects cancellous and cortical bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe disuse osteoporosis

A

Conditions resulting in prolonged immobilisation, typically in neurological or muscle disease.

‘Don’t use it, you lose it’

  • e.g. living outside the effects of gravity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Clinical consequences of osteoporosis

A

Increase in bone fragility

Susceptibility to fracture: micro- or fragility fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Fragility fracture

A

“Low energy” trauma

Mechanical forces that would not ordinarily cause fracture

WHO: fall from a standing height or less, that results in a fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Number of fragility fractures per year

A

Est. 500,000 present at hospital with FF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Cost of fragility fractures to the NHS

A

> £4.4 billion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Hip Fracture (due to fragility) statistics

A

Fatal in 20-30% of cases
Only 30% fully recover
Permanently disables 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Who is at risk of fragility fractures ?

A

Increased risk from > 45 years old
Women more likely than men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Common sites for osteoporotic fractures

A

Proximal humerus
Distal radius

Spine
Femoral neck
Vertebral body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Non-modifiable risk factors for osteoporosis

A

Biological sex
Age
Previous fracture
Family history
Race

Early menopause (<45 year old)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Modifiable risk factors for osteoporosis

A

Smoking
Alcohol
Inactivity

Low calcium
Low BMI

Oestrogen deficiency
Vitamin D deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

State some factors contributing to osteoporotic fracture risk

A

Bone strength (Material properties)
Postural reflexes
Soft padding tissue
Falls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is bone remodelling affected by ?

A

Exercise and Lifestyle
Nutrition
Hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Race and Ethnicity - osteoporosis

A

Prevalence ~50% lower in black Americans than white

Rates of fragility fractures in the UK 4.7x greater in white compared to black women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Chinese women and BMD

A

Chinese women have lower BMD, but lower rates of hip and spine fractures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

GAHT

A

Gender-Affirming Hormone Replacement Therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

BMD

A

Bone Mineral Density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Transgender patients and Osteoporosis

A

Adherence to GAHT may protect BMD of both trans women and trans men.

38
Q

Trans women and BMD

A

Trans women tend to have lower BMD prior to initiation of GAHT.

  • Lower BMD as they are not likely to have been drinking, involved in high impact sports etc.
39
Q

Impact of puberty blockers on BMD

A

Currently unclear what impact puberty blockers have on bone mass and fracture risk.

40
Q

Lifestyle and Nutritional factors affecting osteoporosis

A

Smoking
Excess Alcohol

Sedentary - inactive lifestyle
Prolonged Immobilisation

41
Q

State some conditions / diseases that influence osteoporosis

A

Diabetes
Inflammatory bowel disease
Inflammatory Rheumatic diseases

Chronic liver disease
HIV

Asthma
Endocrine diseases

42
Q

State the common factor of coexisting conditions to osteoporosis

A

Inflammatory link
- formation of osteoclasts come from haematopoetic cells

Hormonal link

Absorption and Ability to process and utilise things from the diet

Neurological links

43
Q

State some drugs that increase the chances of osteoporosis

A

Long term antidepressants

Antiepileptics

Aromatase inhibitors

Oral glucocorticoids

44
Q

Aromatase inhibtors use

A

Breast cancer

45
Q

Oral glucocorticoids use

A

Inflammatory/Immune conditions

46
Q

Proton pump inhibitors use

A

Decrease stomach acid

47
Q

Gonadotrophin releasing hormone agonists use

A

Prostate cancer

48
Q

Long-term medroxyprogesterone acetate (DMPA)

A

Injectable contraceptive

49
Q

Thiazolidinediones

A

Diabetes

50
Q

Risk of another fracture after a previous fragility fracture

A

A previous wrist fracture:

  • doubles risk of future hip fracture
  • triples risk of future vertebral fracture
51
Q

Assessing patients risk of osteoporosis

A

FRAX

WHO- fracture risk assessment test

52
Q

DEXA

A

Dual-energy x-ray absorptiometry scan

53
Q

Describe DEXA

A

Low dose x-rays with 2 distinct energy peaks (one absorbed by soft tissue, and the other by bone)

Subtracting one from the other gives a patients bone mineral density.

54
Q

How to calculate BMD ?

A

DEXA scan

55
Q

T score

A

Comparison with a young adult of the same sex with peak bone mass

56
Q

Normal T score

A

T score:

> -1

57
Q

Osteopenia

A

Bone thinning

T score:

-1 to -2.5

58
Q

Osteoporosis

A

T score

< -2.5

59
Q

Z score

A

Comparison of the patient’s BMD with data from same age/sex/size.

60
Q

Investigations for osteoporosis

A

DEXA score

Bone turnover markers

Ruling out other things:
- thyroid function tests
- testosterone and gonadotropin leves in men

61
Q

Bone turnover markers

A

Urine and/or blood tests, infrequently used but may provide some useful information on treatment success.

62
Q

Bone turnover markers for:

  • Formation
  • Resorption
A

Formation
- bone alkaline phosphatase
- increased levels, increased formation

Resorption
- cross linked C-telopeptide of type 1 collagen (CTX)
- increased levels, increased resorption

63
Q

CTX

A

Fragments of collagen caused by osteoclasts dissolving the bone matrix

Increased abundance indicates increased osteoclast activity

64
Q

Main agents in the pharmacological treatment of osteoporosis

A

Bisphosphonates

Denosumab

Romosozumab

Teriparatide

65
Q

Bisphosphonates

A

Alendronate
Risedronate
Zolendronic acid

66
Q

Denosumab

A

Monoclonal antibody against RANKL

67
Q

Romosozumab

A

Monoclonal Antibody against SOT

68
Q

Teriparatide

A

Peptide fragment of parathyroid hormone (PTH)

69
Q

Function of bisphosphonates

A

Anti-resorptive: disrupts the activity of osteoclasts

70
Q

Function of denosumab

A

Anti-resorptive: disrupts the formation and lifespan of osteoclasts

71
Q

Function of romosozumab

A

Anti-resorptive and anabolic : disrupts osteoclasts, promotes osteoblasts

72
Q

Function of teriparatide

A

Anabolic: promotes osteoblasts

73
Q

Side effects of bisphosphonates

A

GI upset, oesophagitis, mandibular necrosis, uveitis, atypical femur fractures

74
Q

Side effects of denosumab

A

Hypocalcaemia, Mandibular necrosis and Rebound resorption

75
Q

Side effects of romosozumab

A

Hypocalcaemia, Mandibular necrosis and Rebound resorption

76
Q

Side effects of teriparatide

A

Nausea, Headache, Dizziness, Leg Cramps, Hypercalcaemia

77
Q

Describe the mechanism of action of bisphosphonates

A

Bisphosphonates - inhibit the function of osteoclasts BY:
- promoting cell death in osteoclasts

  • inhibit the pathways that allow survival of osteoclasts
  • prevent resorption that is mediated by osteoclasts , disrupting their function even before they die
  • inhibit the formation of osteoclast precursors
78
Q

Function of PTH

A

PTH (parathyroid hormone) which is naturally found in the body and regulates normal bone function

79
Q

Describe the mechanism of action of teriparatide

A

Teriparatide is a fragment of PTH.

If given infrequently, it promotes osteoblasts activity.

It binds to receptors on precursors for osteoblasts, and promotes them to mature into osteoblasts and put down more bone.

80
Q

How should teriparatide be given ?

A

Infrequently

To increases osteoblast activity.

81
Q

What happens if you give teriparatide to a patient constantly what happens ?

A

High levels of PTH for a long period of time inhibits osteoblasts function and increases osteoclasts function.

82
Q

Describe the mechanism of action of denosumab

A

Denosumab is a RANK ligand inhibitor

  • inhibits osteoclasts formation and activity
  • doesn’t affect osteoblasts, maintains osteoblast function
83
Q

SOST

A

Released from osteocytes and is a mediator of communication between osteocytes.

84
Q

Function of SOST

A

SOST is released from osteocytes to the surface of bone and it:

  • negatively regulates osteoblasts, prevents bone formation.
  • positively regulates osteoclasts, accelerates resorption
85
Q

Describe the mechanism of action of romosozumab

A

Increases osteoblast activity
Decreases osteoclast activity

Interacts with SOST - blocks SOST

86
Q

State some other pharmacological options in the treatment of osteoporosis

A

Strontium ranelate

Selective estrogen receptor modulators (SERMS - raloxifene)

Ca2+ supplements

Hormone replacement therapy
- reduced risk of osteoporosis
- increased risk of breast cancer

87
Q

Non-pharmacological interventions for osteoporosis

A

Exercise
Nutrition

Vitamin D and calcium intake

Reduced alcohol / cigarettes

88
Q

Exercise

A

Weight bearing exercise with ‘impact’
- jumping
- skipping

Muscle strengthening exercise

89
Q

Nutrition

A

Not just calcium and vitamin D, needs a balanced and healthy diet

90
Q

Vitamin D and calcium intake

A

Sunlight, food, supplements
(esp. during pandemic)

Medicine Year 1 - Semester 2 - Part 2 (53 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions