Lab Values for Bone Conditions

Question 1

What bone condition is associated with normal labs but decreased bone mass?

Answer 1

osteoporosis

Question 2

What bone condition is associated with only increased ALP ‘mosaic’ bone architecture?

Answer 2

Paget disease of bone

Question 3

What bone condition is associated with only decreased serum Ca2+ in severe disease but mostly has normal labs in mild disease but presents with dense, brittle bones that break like chalk?

Answer 3

Osteopetrosis

Question 4

What bone condition is associated with increased serum Ca2+ and phosphate but decreased PTH?

Answer 4

Hypervitaminosis D

Question 5

What are the causes of Hypervitaminosis D?

Answer 5

• oversupplementation

- granulomatous disease (e.g. sarcoidosis)

Question 6

What labs are consistent with Osteomalacia/rickets?

Answer 6

• increased ALP and PTH

- decreased serum Ca2+ and phosphate

Question 7

What bone condition is associated with increased serum Ca2+, ALP, and PTH and decreased phosphate?

Answer 7

• osteitis fibrosa cystica

- primary hyperPTHism

Question 8

How does secondary hyperPTHism present differently in labs from primary?

Answer 8

increased ALP and PTH, but phosphate is increased and serum Ca2+ is decreased

Question 9

What is a common cause of secondary hyperPTHism?

Answer 9

often a compensation for CKD (decreased phosphate excretion and production of activated vitamin D)