Phosphate Binder, Phosphate Diet Act Synergistically
SAN DIEGO—Lanthanum carbonate acts in synergy with dietary phosphate restriction to decrease levels of fibroblast growth factor 23 (FGF-23) in patients with chronic kidney disease (CKD) and normal phosphate levels, researchers reported at Kidney Week 2012.
In a single-blind, three-month study, Tamara Isakova, MD, of the University of Miami Miller School of Medicine, and colleagues randomly assigned 39 patients with stage 3-4 CKD and normal serum phosphate levels to one of four groups: ad lib diet plus placebo (10 patients); 900-mg phosphate diet plus placebo (10 patients); ad lib diet plus lanthanum carbonate (11 patients); and a 900-mg phosphate diet plus lanthanum carbonate (eight patients). The lanthanum carbonate dose was 1,000 mg three times daily with meals. Dietary restriction was accomplished with counseling.
At baseline, the mean estimated glomerular filtration rate was 38 mL/min/1.73 m2 and the mean serum phosphate level was 3.6 mg/dL. The median FGF-23 level was 128 RU/mL. Phosphate diet alone and lanthanum carbonate alone was associated with a significant 22% and 19% decrease in FGF-23. The phosphate diet-lanthanum carbonate group, however, experienced a significant 35% decrease in FGF-23, suggesting synergy between diet and lanthanum carbonate, the researchers reported.