Osteoporosis

Question 1

What are the “osteo” cell types & what do they do?

Answer 1

Cytes: Maintain mineral concentration in matrix.
Blasts: Bone formation.
Clasts: Bone resorption.
Genic Cells: Develop into Osteoblasts.

Question 2

Age-related bone remodeling presents how?

Answer 2

-Increased bone resorption.
-Reduced Trabecular number & thickness.
-Increased Trabecular spacing.
-Cortical Thinning.
-Expansion of Bone Marrow Cavity.

Question 3

Osteoporosis affects 1 / ___ women over the age of 50.

Answer 3

4

Question 4

What are the risk factors for Primary Osteoporosis?

Answer 4

-Low initial bone mass
-Ethnicity
-Smoking
-Shitty Diet
-Age-related Metabolism Changes

Question 5

How does the etiology of Primary & Secondary Osteoporosis differ?

Answer 5

Primary: Cause is unknown.
Secondary: Brought upon by other bone-affecting diseases.

Question 6

What are some secondary causes of Osteoporosis?

Answer 6

-Autoimmune Disorders (RA, Lupus, MS, Ankylosing Spondylitis)
-Digestive / GI (Celiac, IBD, Weight Loss Surgery)
-Blood Cancers
-Neuro Disorders (MS / Parkinson’s / Spinal Cord Injury)
-Mental Illness
-Endocrine Disorders (Hyperthyroidism, Cushing’s, Low Test / Estrogen in men)
-Other Misc. Disorders (HIV, Female Athlete Triad, CKD, COPD, Liver Disease, Scoliosis, Pregnancy-Related)

Question 7

What is the pathogenesis of Osteoporosis?

Answer 7

Bone Cells Resorbed&raquo_space;> Bone Cells Deposited

-Leads to progressive bone density loss & thinning of bone tissues.

Question 8

Within the Wnt Signaling Pathway, what two molecules inhibit Osteoblast activity?

Answer 8

DKK-1
Sclerostin

Question 9

In the presence of low Ca2+, PTH stimulation serves to inhibit the activity of ________, which allows for Osteoblastic activity.

Answer 9

Sclerostin

Question 10

OPG in the bone resorptive pathway acts how?

Answer 10

-Suppresses Preosteoblast differentiation into Osteoclasts.

Question 11

How does sRANKL act in the bone resorptive pathway?

Answer 11

-Stimulates Osteoclast activity & maturation.

Question 12

In the presence of high Ca2+ levels, ________ serves to suppress Osteoclast activity.

Answer 12

Calcitonin

Question 13

What are some consequences of Osteoporosis?

Answer 13

-Fracture Risk Increase
-Fall Risk Increase
-Loss of Height
-Stooped Posture

Question 14

What do Bisphosphonate drugs do?

Answer 14

1) Slow down bone resorption actions of Osteoclasts.
2) Promote Osteoclast apoptosis.

Question 15

What do Bisphosphonate drugs end in?

Answer 15

“dronate”

Alendronate
Etidronate
Risedronate
Zoledronic Acid

Question 16

Why does long-term use of Bisphosphonate drugs increase femoral fracture risk?

Answer 16

-No ability to remodel bone (b/c Osteoclast activity reduced).

Question 17

Side effects of Bisphosphonates?

Answer 17

-Esophageal Irritation
-Osteonecrosis of the Jaw

Question 18

How does Denosumab work?

Answer 18

-Prevents RANK / RANKL interaction, which suppresses Osteoclast formation.

Must be injected routinely q6mths, or else new bone laid down dissipates!

Question 19

What does Estrogen / Progesterone usage do for Osteoporosis patients?

Answer 19

-Increases bone density.

Question 20

Raloxifene is classified as a what?

Answer 20

SERM (Selective Estrogen Receptor Modulator)