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Flashcards in Metabolic Bone Diseases Deck (103)
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1

Metabolic Bone Diseases

Osteoporosis
Paget's disease
Osteomalacia
Rickets
Renal osteodystrophy

2

Pathophysiology of Osteoporosis

Bone resorption outpaces bone deposition

3

Negative Feedback Loop for Bone Remodeling

Hormonal process that maintains calcium homeostasis

4

Types of Stress on the Skeleton

Mechanical
Gravitational

5

What is osteoclast activity stimulated by?

PTH
Calcitonin (low levels)
GF
IL-6
Lack of gonadal hormones

6

Osteoblasts

Builders of bone matrix
Decreased number with aging

7

How can the thyroid gland stimulate or inhibit osteoclast activity?

Hyperthyroidism: stimulate osteoclast activity
Increased plasma calcium: release of calcitonin

8

Risk Factors for Osteoporosis

Age (>50)
Gender
Race (white, Asian)
Activity level
Diet
Hormonal
Meds: gonadal hormones
Family history
Medical history

9

Components of Diet in Osteoporososis

ETOH
Tobacco
Low calcium intake or altered ability to absorb

10

Hormonal Aspects with Osteoporosis

Amenorrhea
Late menarche
Early menopause
Post menopausal state
Low testosterone
Low estrogen

11

Medical Conditions Associated with Osteoporosis

Rheumatologic conditions
Malabsorption syndromes
Hypogonadism
Hyperthyroidism
Chronic kidney disease
Chronic liver disease
COPD
Neurologic disorders (unable to ambulate or exercise)
DM

12

Medications that can Decrease Bone Density

Heparin
Warfarin (+/-)
Cyclosporine
Medroxyprogesterone acetate (Provera)
Vitamin A
Loop diuretics
Chemo drugs
Antiseizure meds
PPIs
H2 blockers
Antidepressants (TCA's & SSRI's)
Glucocorticoids

13

Prevention of Osteoporosis

Exercise
Appropriate vitamin D and calcium intake
Cessation of tobacco use
ETOH in moderation
Screening tests

14

What is the standard test for the evaluation of bone mineral density?

DEXA scan

15

Indications for a DEXA Scan

Currently treated or considering pharmacologic therapy for osteoporosis
Anyone not receiving therapy in whom evidence of bone loss would lead to treatment
Screening for osteoporosis

16

DEXA Scan Screening Guidelines

Women >65
Men >70
Younger postmenopausal women and men with risk factors
Adults with fragility fractures
Condition associated with low bone mass
Medications associated with low bone mass

17

Define T-Score

Bone mineral density compared to what is normally expected in a young healthy adult based on gender

18

What T-score indicates osteoporosis?

Less than 2.5

19

In what populations is a Z-score used instead of a T-score?

Premenopausal women
Men younger than 50
Children
African Americans
Native Americans

20

What is quantitative calcaneal ultrasonography effective at predicting?

Femoral neck, hip, & spine fractures

21

Pros of Quantitative Calcaneal Ultrasonography

Lower cost than DEXA scan
Portable
No radiation exposure
Screening test NOT diagnosis

22

Indications for Vertebral Imaging for Osteoporosis Screening

Bone testing not available in women >70 and men >80
T-scores of -1.5 in women 65-69 and men 75-79
Women 50-64 and men 50-69 with risk factors
Low trauma fracture
Historical height loss of 1.5"+
Prospective height loss of 0.8"+
Recent/ongoing long term glucocorticoid treatment

23

After initial vertebral imaging, when should you reemerge to evaluate?

Loss of height
Suspect new vertebral fracture
New back pain
Postural change

24

Work Up of Osteoporosis

H&P
Labs
+/- x-rays
DEXA scan

25

History in the Workup of Osteoporosis

Any history of disease
Family history
History of low vitamin D, prior bone density testing, or prior fractures
Medication review

26

Signs and Symptoms of Osteoporosis

Asymptomatic unless fracture
Gradual loss of height
Dowager's hump

27

Possible Labs to Diagnose Osteoporosis (Depends on comorbidities & history)

CBC
CMP
Serum magnesium
TSH
25-OH vitamin D
PTH
Testosterone (younger men)
24 H urine calcium

28

Indications for X-ray to Look for Osteopenia

Symptomatic patients
Asymptomatic patients if vertebral fracture suspected

29

Non-Pharmacologic Treatment of Osteoporosis

Calcium
Vitamin D
Exercise

30

SE of Calcium

Nephrolithiasis
Dyspepsia
Constipation
Interfere with absorption of iron and thyroid hormone