Abstract: FR-PO1072

Effect of Phosphate Binders on Biochemical and Vascular Outcomes in Patients with Non-Dialysis Dependent CKD

Session Information

Category: Mineral Disease

  • 1205 Vascular Calcification

Authors

  • Kovesdy, Csaba P., University of Tennessee Health Science Center, Memphis, Tennessee, United States
  • Lu, Jun Ling, University of Tennessee Health Science Center, Memphis, Tennessee, United States
  • Han, Zhongji, University of Tennessee Health Science Center, Memphis, Tennessee, United States
  • Thomas, Fridtjof, University of Tennessee Health Science Center, Memphis, Tennessee, United States
  • Quarles, Leigh Darryl, University of Tennessee Health Science Center, Memphis, Tennessee, United States
  • Jarmukli, Nabil, Salem VAMC, Salem, Virginia, United States
Background

Abnormal phosphate (P) homeostasis develops early in CKD and is associated with adverse clinical outcomes. It is unclear if normalization of P homeostasis results in improved clinical outcomes in patients with non-dialysis dependent (NDD) CKD.

Methods

We randomized 120 patients with CKD stages 3-4 in a 1:1:1 ratio to open-label lanthanum carbonate, calcium acetate or dietary phosphorus restriction for one year (3 months titration and 9 months maintenance). The co-primary outcomes were month 12 (vs. baseline) biochemical (serum and urinary P, PTH, calcium, bone-specific alkaline phosphatase [bALP], and FGF-23) and vascular parameters (coronary artery calcium [Agatson score], arterial stiffness [pulse wave velocity, PWV] and endothelial dysfunction [reactive hyperemia index, RHI]) in all patients. Secondary outcomes were between-treatment differences in change for each parameter between month 12 and baseline. All analyses were intention-to-treat.

Results

Patients were 66.1±11.4 years old, 87% male, 52% African American, 55% diabetic, and their baseline eGFR was 32±10 ml/min/1.73m2. Baseline characteristics were similar between the intervention arms (p>0.5).
107 of 120 (89%) randomized patients completed 12 months of follow-up. Differences were not significant at month 12 (vs. baseline) for any of the outcomes (Table) except bALP and FGF-23. Changes for all outcomes were similar in the three arms except for PTH, which was suppressed more effectively by calcium acetate (p<0.001, data not shown).

Conclusion

A 1-year intervention to limit P absorption using dietary restriction or two different P binders resulted in decreased bALP suggesting improvement in bone turnover, but no other significant changes in biochemical or vascular parameters in patients with NDD CKD.
(NCT01357317)

 BaselineMonth 12p
Phosphorus (mg/dl)3.8±0.63.7±0.80.15
PTH (pg/ml)141 (105, 203)146 (92,204)0.5
TRP (%)0.63±0.140.64±0.160.5
Calcium (mg/dl)9.2±0.59.1±0.60.15
Bone-specific ALP (mcg/L)15.8 (12.1, 21.1)13.8 (10.6, 17.6)<0.001
FGF-23 (pg/ml)133 (86, 189)132 (99, 216)0.002
PWV (m/sec)11.5 (8.7, 13.1)10.7 (8.5, 13.7)0.4
CAC (Agatson score)356 (40,1016)309 (51,1048)0.5
RHI2.03±0.592.05±0.610.8

P values are for paired t tests

Funding

  • Veterans Affairs Support