CKD Mineral and Bone Disorder

Question 1

PTH acts on what 3 things? Directly or indirectly?

Answer 1

Directly on bone and kidney

Indirectly on intestine

Question 2

Calcitriol

Answer 2

1,25 (OH)2 Vitamin D
Potent
Main active vitamin D metabolite
Acts on bone, kidney and intestine

Question 3

FGF-23

Answer 3

Fibroblast growth factor-23
Expressed in osteocytes
Acts on FGF receptors in concert with the necessary protein co-factor Klotho

Question 4

PTH effect on

1. Bone
2. Kidney
3. Intestine

Answer 4

1. Increases Ca and PO4 resorption
2. Increases Ca resorption, increase PO4 excretion, increases calcitriol activation
3. Indirect effect through increased calcitriol

Question 5

Calcitriol effect on the

1. Bone
2. Kidney
3. Intestine

Answer 5

1. Increase Ca resorption, increase PO4 resorption
2. Same
3. Same

Question 6

Fgf-23 effect on the

1. Bone
2. Kidney
3. Intestine

Answer 6

1. Uncertain
2. Increase PO4 excretion, decrease calcitriol activation
3. Indirect effect through decreased calcitriol

Question 7

Normal result of

1. Increase PTH
2. Increased Calcitriol
3. Increases FGF-23

Answer 7

1. Increase serum Ca, net effect to mildy reduce serum PO4
2. Increase both serum Ca and serum PO4
3. Reduce serum PO4 and reduce calcitriol activation

Question 8

3 treatment targets in the secondary hyper PTH of CKD

Answer 8

Hyperphosphatemia
Hypocalcemic
Decreased calcitriol activation

Question 9

Treatment of CKD-MBD

Answer 9

Limit persistent hyperphosphatemia (oral, then binders)
Consider normalizing serum Ca
Consider calcitriol use only in more advanced CKD with rising/severe hyperPTH
In dialysis patients, consider using calcimimetics to improve PTH gland sensitivity to Ca
Maintain target PTH level for degree CKD