The percentage of non-oxidized PTH concentration remains stable over a period of 1 year in hemodialyzed patients.

Abstract Introduction Non-oxidized (n-ox) PTH could better reflect PTH activity. We have evaluated the evolution of n-ox PTH and intact PTH (iPTH) in hemodialyzed (HD) patients over a period of 1 year. Material and methods We measured iPTH and n-ox PTH in 66 stable HD patients and we measured iPTH and n-ox PTH at baseline and after 1, 3, 6 and 12 months. We considered that no significant changes in iPTH and n-ox PTH occurred if two consecutives measurements of iPTH and n-ox PTH for the same patient remained in the baseline value ±43%. We also considered that changes over time were concordant if both values of the same patients increased or decreased together (in the same direction) by more than 43%. Results The median [p25; p75] was 229.4 [1.5,4; 352.5] pg/mL for iPTH and 24.4 [15,1; 38.7] pg/mL for n-ox PTH. N-ox PTH fraction represented 11.3 [9.0; 13.7]% of the total iPTH and the ratio n-oxPTH/iPTH ranged from 5.1 to 35.7%. After 1 year, 84% of the patients presented a perfect concordance of the evolution of the 2 moieties and no severe discordance was noticed. Conclusions The percentage of n-ox PTH is stable over time in stable HD patients.