A recent patient chart audit found that evaluating the proportion of patients above target phosphorus level in a single month may underestimate the magnitude of the problem1,2
Demonstrated in a 2019 chart audit including the records of 1,015 patients on dialysis and on phosphorus-lowering therapy, submitted by 159 nephrologists.
Target phosphorus levels were defined as ≤5.5 mg/dL.1
Evaluating the proportion of patients above target in a single month may underestimate the magnitude of the problem.
Both elevated phosphorus and time spent with elevated phosphorus increase the risk of cardiovascular mortality3-6
Likelihood of death for patients on dialysis was significantly increased when serum phosphorus levels were only 0.5 mg/dL to 1 mg/dL over the reference range of 4.0 mg/dL to 5.0 mg/dL.3
Area under the curve (AUC) takes into account both the serum phosphorus concentration and the amount of time a patient’s serum phosphorus concentration was above the target range. Patients with higher AUC values had worse phosphorus control; for example, a patient maintaining a serum phosphorus level of exactly 5.5 mg/dL or 6.5 mg/dL over 6 months would have an AUC of 1 or 2, respectively.6
Lopes MB, Karaboyas A, Bieber B, et al. Impact of longer term phosphorus control on cardiovascular mortality in hemodialysis patients using an area under the curve approach: results from the DOPPS. Nephrol Dial Transplant. 2020;35(10):1794-1801. doi: 10.1093/ndt/gfaa054. Adapted and reproduced by permission of Oxford University Press on behalf of the ERA-EDTA.
Clinical practice guidelines for lowering elevated phosphate levels
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What are the difficulties from the healthcare team’s perspective?
Chief of Nephrology
How do patients feel about managing their phosphorus?
Looking deeper into the science of phosphate absorption has revealed the primacy of the paracellular pathway
Chief, Division of Nephrology and Hypertension
Northshore University HealthSystem
We now know that the paracellular pathway is the primary pathway by which phosphate absorption occurs10-12
1Paracellular absorption occurs passively along concentration gradients through tight junction complexes between cell membranes.10,11
- The paracellular pathway is responsible for the bulk of phosphate absorption and does not appear to saturate12-14
2Transcellular absorption occurs via active transport through cell membranes and is less relevant as a mechanism of phosphate absorption in humans.10,11