Researchers investigated whether higher phosphorus levels are associated with anemia in individuals with normal kidney function and early chronic kidney disease (CKD). The population-based study was conducted within the Kaiser Permanente Southern California health system from 1998 to 2013, involving individuals aged 18 and older with an estimated glomerular filtration rate >30 mL/min/1.73 m2. The study excluded those with secondary causes of anemia. Researchers analyzed the odds ratio (OR) for moderate anemia (hemoglobin <11 g/dL) and mild anemia (<12 g/dL for females and <13 g/dL for males).

Among 155,974 participants, 4.1% had moderate anemia, and 12.9% had mild anemia. The findings indicated that serum phosphorus levels ≥3.5 mg/dL were associated with both mild and moderate anemia. Specifically, the OR for moderate anemia was 1.16 for every 0.5 mg/dL increase in phosphorus and 1.26 in the highest vs middle phosphorus tertile. The study concludes that higher phosphorus levels are linked to a greater likelihood of anemia in individuals with early CKD and normal kidney function, suggesting phosphorus may serve as a biomarker for anemia and impact hematopoiesis.

Reference: Tran L, Batech M, Rhee CM, et al. Serum phosphorus and association with anemia among a large diverse population with and without chronic kidney disease. Nephrol Dial Transplant. 2016;31(4):636-45. doi: 10.1093/ndt/gfv297.