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Flashcards in Metabolic Bone Disease Deck (62):
1

What is the definition of osteoporosis?

Bone deterioration with reduced bone mass, and disruption of the microarchitecture of the bone

2

What is the T score on a DXA scan that indicates osteoporosis?

-2.5

3

Which bone fracture has the highest mortality rate?

Hip

4

What is the #1 cause of nursing home admissions in the US?

Hip fracture

5

What percent of women over 50 years will suffer an osteoporosis related hip fracture?

50%

6

What are the major issues post hip fracture?

-Increased risk of mortality
-Decreased ability to do ADLs

7

What is the general amount of treatment (epidemiologically) given post hip fracture?

Low

8

What is the gold standard in diagnosing osteoporosis?

DXA scan

9

What is the T and Z score for DXA scans?

T = compared to young adults
Z = compared to age-matched adults

10

True or false: DXA scan results are race and gender matched

True

11

What is the definition of osteopenia as diagnosed by DXA scan?

-1.0 to -2.5

12

What is considered normal per DXA scan?

-1.0 to +1.0

13

True or false: anyone with a fragility fracture, by definition, has a diagnosis of osteoporosis, regardless of T or Z score

True

14

Who are T scores used for?

Postmenopausal women, and men over 50 yo

15

Should you ever use a T score in a DXA scan for children?

No

16

When is a Z score used compared to a T score, in terms of DXA scans?

In patients who are younger than peak bone mass:
-Premenopausal women
-Men less than 50

17

What is the diagnostic criteria for osteoporosis in terms of Z scores?

less than -2.0

18

What is the role of smoking and excessive EtOH consumption in the risk for fracture?

Increases the risk

19

What is the role of body weight in terms of risk for fracture?

Lower weight = higher risk

20

What is the recommended dose of Vit D3 for patients over 50 years?

800 -1000 IU / d

21

What are the five recommendations that should be made to patients over 50 years old to reduce the risk for osteoporosis?

-Counsel risk of OP and fractures
-Check for secondary causes
-Vit D3 intake
-Weight bearing exercises
-Avoid smoking and excess EtOH

22

What is the recommended amount of Ca for patients over the age of 50?

1200 mg/d

23

When should BMD testing begin in men and women?

Men = over 70
Women = over 65

24

When is BMD testing indicated for men/women over 50?

Concern for OP based on risks

25

At what T score should therapy begin for osteoporosis, according to the FRAX model? What about in relation to their 10 year hip fracture probability? What about all major osteoporosis related fractures?

T score between -1 to -2.5 at the femoral neck, hip, or spine

10 year hip fracture probability of more than 3%

10 year all fractures more than 20%

26

Why is it that age is more important than T scores?

Quality of bone lessens with age

27

How often should BMD testing be performed for patients on pharmacotherapy?

2 years

28

What is the FRAX model?

mathematical model that predicts the risk of hip frature based on risk factors

29

True or false: the FRAX model is only to be applied to patients who are treatment naive

True

30

What is the only DXA scan data (which bone) does the FRAX model take into account?

Femoral neck

31

What is the anabolic therapy for osteoporosis?

Teriparitide

32

What are the three anticatabolic therapies available for osteoporosis?

-bisphosphonates
-SERMs
-Denosumab

33

What are the most efficacious drugs used for osteoporosis?

bisphosphonates

34

What is the MOA of bisphosphonates?

Binds to hydroxyapatite, and inhibits osteoclast action by causing apoptosis

35

What is the MOA of denosumab?

binds to the RANK-L, and inhibits activation via RANK receptor (osteoclast-mediated bone destruction)

36

What is the MOA of teriparatide? How is it given in terms of dosing?

a recombinant form of parathyroid hormone. It is an effective anabolic agent

Low dose leads to bone growth, whereas high dose = destruction

37

Chronically elevated alk phos is seen in what disease?

Paget's disease

38

What, generally, is Paget's disease of the bone?

Accelerated bone turnover and abnormal bone remodeling.

39

What are the histological characteristics of Paget's disease of the bone?

Osteoclasts with multiple nuclei

40

True or false: the majority of Paget's patients are asymptomatic

True

41

What are the s/sx of Paget's disease of the bone, when they occur?

Arthritis
Bone deformity
Fracture

42

What are the complications of bony deformities of Paget's disease?

Nerve impingement (e.g. sciatica, CN palsies, hearing loss, HA, etc.)

43

What are the labs that are elevated with Paget's disease of the bone?

Alk phos

44

True or false: Ca and Phosphate levels in Paget's disease of the bone are typically elevated

false--typically normal

45

What should be done for all patients with a diagnosis of Paget's disease? Why?

baseline bone scan, and radiographs of affected sites

can help you diagnose bone changes later on, and differentiate from Paget's disease

46

True or false: the areas affected by Paget's disease often change throughout a person's lifetime

False--rarely do they change

47

What is the goal of PDB treatment?

Ease pain and normalize bone remodeling

48

When should PDB be treated? (3)

If symptomatic
Alk phos is elevated
bone scan reveals increased activity

49

What is the drug category of choice for PDB?

bisphosphonates--Zoledronic acid in particular

50

What are the two processes that are defective in Rickets?

-Deficient mineralization at the growth plate
-architectural disruption of bone structure

51

What usually causes calcipenia rickets?

Dietary deficiency of Vit D and/or Ca

52

What causes phosphatemic rickets?

Renal phosphate wasting--may be caused by fanconi syndrome

53

What is Fanconi's syndrome?

disease of the proximal renal tubules in which glucose, amino acids, uric acid, phosphate and bicarbonate are passed into the urine, instead of being reabsorbed.

The loss of bicarbonate results in type 2 or proximal renal tubular acidosis.

54

What are the skeletal findings of both calcipenic and phosphopenic rickets?

-Delayed closure of the fontanelles
-Frontal bossing
-Rachitic rosary

55

What are the wrist findings of Rickets?

Widening

56

What are the s/sx of osteomalacia?

-bone pain and muscles weakness
-Bone TTP
-fracture
-muscle spasms/ cramps

57

What is the characteristics gait with osteomalacia?

Osteomalacia

58

What happens to alk phos, PTH, and vit D levels in osteomalacia?

Vit D is decreased, with compensatory increase in PTH and alk phos

59

How often is alk phos elevated with osteomalacia?

95-100%

60

Looser's lines = ?

Looser zones, also known as cortical infractions, or Milkman's lines, are wide, transverse lucencies traversing part way through a bone, usually at right angles to the involved cortex and are associated most frequently with osteomalacia and rickets.

61

What level of Vit D is considered satisfactory? What is the goal for those in treating osteoporosis?

20 ng /ml = you're all good

30 ng/ml + for osteoporosis

62

What causes the high output HF with PDB?

Tons of new arterial connections in bones leads to much larger need for CO