Longitudinal Study to Find the Association of Serum Phosphorus Level with FGF23 in Three Different Hyperphosphatemia Management Groups of Stage 3 and 4 Chronic Kidney Disease (CKD) Patients.

Background: There is paucity of clinical evidence on target serum phosphorus levels in early chronic kidney disease (CKD). Present longitudinal study was done to find target phosphorus level and its association with fibroblast growth factor (FGF23) in three different hyperphosphatemia management groups. Methods: This 1-year, prospective, randomized controlled, open-labelled study was conducted among three equally allocated treatment groups that consisted of 120 screened early CKD patients totally. Group 1 patients were given dietary phosphorus modification ( Results: At baseline, all clinical and biochemical parameters were equally distributed with a controlled nutritional phosphate among all groups. There was no significant difference of FGF23 levels from all the three categories of phosphorus level among all groups. Serum phosphorus at the level of 5 mg/dl was associated with iPTH and eGFR at 1 year. Over 1 year, there was a significant decline in serum phosphorus levels in group 1 ( Conclusion: Serum phosphorus levels upto 5mg/dl had no effect on FGF23 at early CKD stages. Although different treatment groups showed significant phosphorus reduction, non-calcium phosphate binder had a major impact on FGF23 reduction.