Effects of phosphate binders in moderate CKD

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Pharmacology

Background:

• Phosphate binders are proposed for chronic kidney disease (CKD) patients due to phosphorus-mortality links.
• Safety and efficacy of phosphate binders in CKD are not well-established.

Purpose of the Study:

• To assess phosphate binders' effects on mineral metabolism and vascular calcification in moderate to advanced CKD.
• Evaluate changes in serum phosphorus, parathyroid hormone, and FGF23 levels.

Main Methods:

• 148 CKD patients (eGFR 20-45 ml/min/1.73 m²) were randomized to calcium acetate, lanthanum carbonate, sevelamer carbonate, or placebo.
• Primary endpoint: change in mean serum phosphorus over 9 months.
• Secondary endpoints included urine phosphorus, PTH, FGF23, and vascular calcification.

Main Results:

• Phosphate binders slightly reduced serum phosphorus (3.9 vs 4.1 mg/dl) and significantly decreased 24-hour urine phosphorus (by 22%).
• Serum intact parathyroid hormone stabilized with binders versus increasing with placebo (P=0.002).
• Binders significantly increased coronary artery and abdominal aorta calcification (18.1% and 15.4% median increase, respectively).

Conclusions:

• Phosphate binders effectively lower phosphorus and attenuate secondary hyperparathyroidism in CKD patients with near-normal phosphorus levels.
• However, phosphate binders promote vascular calcification progression.
• The overall safety and efficacy of phosphate binders in CKD remain uncertain.