What are the effects of hyperphosphatemia?

From the Guidelines

Elevated phosphorus levels in the blood can lead to serious health complications, including calcification and organ damage, and should be managed through dietary restriction, phosphate binders, and treatment of underlying conditions, as supported by recent studies 1.

Key Considerations

• High phosphate concentrations are linked to mortality among patients with chronic kidney disease (CKD) stage G3a to G5 and transplant recipients 1.
• Treatment decisions should be based on trends of serial measurements of phosphate, calcium, and parathyroid hormone (PTH) considered together, rather than a single laboratory value 1.
• Dietary phosphorus restriction and phosphate binders, such as calcium acetate, sevelamer, or lanthanum carbonate, are commonly used to manage hyperphosphatemia 1.

Management Strategies

• Limiting dietary phosphate intake is recommended for patients with CKD G3a to G5D, with consideration of phosphate source (e.g., animal, vegetable, additives) 1.
• Phosphate-lowering therapies may only be indicated in the event of progressive or persistent hyperphosphatemia, and not for prevention 1.
• Calcium-based phosphate binders should be used with caution, as excess exposure to calcium may be harmful across all GFR categories of CKD 1.

Important Findings

• Recent studies have shown that maintaining normal serum phosphate levels may not be beneficial in patients not receiving dialysis, and that aggressive phosphate-lowering therapy may have safety concerns 1.
• The use of calcium-free phosphate-binding agents may be preferred over calcium-based agents for treatment of hyperphosphatemia 1.

From the FDA Drug Label

Administration of calcitriol to patients in excess of their daily requirements can cause hypercalcemia, hypercalciuria, and hyperphosphatemia. The serum calcium times phosphate (Ca x P) product should not be allowed to exceed 70 mg2/dL2. If serum phosphorus levels exceed 5.0 mg/dL to 5.5 mg/dL, a calcium-containing phosphate-binding agent (i.e., calcium carbonate or calcium acetate) should be taken with meals.

Elevated phosphorus levels can lead to hyperphosphatemia. To manage this condition, a calcium-containing phosphate-binding agent should be taken with meals if serum phosphorus levels exceed 5.0 mg/dL to 5.5 mg/dL. Additionally, the serum calcium times phosphate (Ca x P) product should be monitored to prevent it from exceeding 70 mg2/dL2 2.

From the Research

Effects of Elevated Phosphorus

• Elevated phosphorus levels, or hyperphosphatemia, can lead to various health issues, including abnormal bone mineralization, extra-osseous calcification, and increased risk of cardiovascular events and death 3.
• Hyperphosphatemia is often associated with chronic kidney disease (CKD) and can contribute to the development of CKD-mineral and bone disorder (MBD) 4.
• Increased serum phosphorus levels can also lead to bone disease, vascular calcification, and cardiovascular disease 4.

Treatment and Management

• Several classes of oral phosphate binders are available to help control plasma phosphorus levels, including calcium-based binders, lanthanum, sevelamer, and iron-based binders 3.
• Dietary phosphate restriction and phosphate binder therapy are commonly used to manage hyperphosphatemia in CKD patients 4, 5.
• Vitamin D supplementation can also be used to improve vitamin D deficiency and parathyroid hormone (PTH) levels, but may worsen phosphate retention and increase FGF-23 levels 4.
• The choice of phosphate binder depends on various factors, including the patient's individual needs, side effects, and cost 5.

Clinical Outcomes

• Achieving normal phosphorus levels is associated with distinct clinical benefits, including reduced risk of cardiovascular events and death 4.
• However, the beneficial effects of phosphate binder therapy on hard clinical outcomes have not been convincingly demonstrated in prospective clinical trials 6.
• Early intervention and prevention of hyperphosphatemia may be beneficial in reducing the risk of cardiovascular disease and other complications associated with CKD-MBD 6, 7.