IN the News: Phosphate binders and CKD

A recent publication in JASN by Block et al compared >100 patients head to head on placebo, lanthanum, sevelamer and calcium acetate and looked at few end points:- Change in mean serum phosphorus, urinary phos, pth, 1,25 vitamin D levels, FGF23 levels and vascular calcifications and bone density scores in CKD patients. The study proposes that although the parameters in above all improved, there was a concern that binders might progress vascular calcifications.

Few take home points
1. Mean phos levels did decline in all groups compared to placebo.
2. Urinary phos levels were also different in active vs placebo group.
3. PTH levels increased with placebo and remained stable with active therapy
4. FGF-23 were elevated at baseline and didn't change much in both active and placebo groups
5. Bone mineral density improved in active patients
6. Active therapy resulted in significant increases in median annual percent change in coronary artery and abdominal aorta.

Few inferences and discussion points
1. Although randomized and controlled, this study has a small n and once distributed had only few patients <50 per group.
2. Baseline phos levels to begin with were in 4.0 range suggesting good control already
3. There were less patients with CHF and HTN in the placebo group ( perhaps effecting the results?)
4. Vascular calcifications noted in coronary and abdominal aorta might not truly reflect cardiac events.
5. Commendable work but more larger studies need to be done to confirm these findings.
6. Just like anemia story, perhaps the Phos study might have the same ending.