Effects of phosphate binder therapy on vascular stiffness in early-stage chronic kidney disease

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Mineral and Bone Metabolism

Background:

• Cardiovascular disease (CVD) risk is elevated in chronic kidney disease (CKD), partly due to CKD-mineral bone disorder (CKD-MBD).
• Vascular manifestations of CKD-MBD, including vascular stiffness, carotid artery intima-media thickness (cIMT), and vascular calcification (VC), are linked to phosphorus levels.
• Phosphorus is a recognized CVD risk factor in CKD patients.

Purpose of the Study:

• To investigate if lanthanum carbonate (LaCO3) modifies phosphorus balance in early CKD without causing hypophosphatemia.
• To assess the effect of LaCO3 on vascular manifestations of CKD-MBD, including vascular stiffness, cIMT, and VC.
• To evaluate changes in phosphate homeostasis and CKD-MBD biomarkers.

Main Methods:

• A 12-month, randomized, double-blind, placebo-controlled pilot study.
• 38 participants with normophosphatemic stage 3 CKD received a fixed dose of LaCO3 or placebo.
• Primary outcome: change in serum phosphorus. Secondary outcomes: phosphate homeostasis, pulse wave velocity (PWV), cIMT, VC, and CKD-MBD biomarkers.

Main Results:

• No statistically significant differences were observed between LaCO3 and placebo groups in serum phosphorus, urinary phosphorus, or tubular reabsorption of phosphorus.
• LaCO3 treatment did not significantly alter PWV, cIMT, or VC over 12 months.
• Baseline elevations in CKD-MBD biomarkers (FGF-23, DKK1, sclerostin) were not affected by LaCO3.

Conclusions:

• Twelve months of LaCO3 treatment did not impact serum phosphorus levels or phosphate homeostasis in early CKD.
• LaCO3 did not demonstrate efficacy in altering vascular stiffness, cIMT, VC, or key CKD-MBD biomarkers.
• This pilot study suggests LaCO3 may not be effective for managing vascular aspects of CKD-MBD in early, normophosphatemic CKD.