Tepel, Martin4; Armbruster, Franz Paul3; Grön, Hans Jürgen3; Scholze, Alexandra5; Reichetzeder, Christoph3; Roth, Heinz Jürgen3; Hocher, Berthold3
1 Kardiovaskulær og Renal Forskning, Department of Molecular Medicine, Det Sundhedsvidenskabelige Fakultet, SDU2 Nephrology, Department of Clinical Research, Det Sundhedsvidenskabelige Fakultet, SDU3 unknown4 Kardiovaskulær og Renal Forskning, Department of Molecular Medicine, Det Sundhedsvidenskabelige Fakultet, SDU5 Nephrology, Department of Clinical Research, Det Sundhedsvidenskabelige Fakultet, SDU
Background: It was shown that nonoxidized PTH (n-oxPTH) is bioactive, whereas the oxidation of PTH results in a loss of biological activity. Methods: In this study we analyzed the association of n-oxPTH on mortality in hemodialysis patients using a recently developed assay system. Results: Hemodialysis patients (224 men, 116 women) had a median age of 66 years. One hundred seventy patients (50%) died during the follow-up period of 5 years. Median n-oxPTH levels were higher in survivors (7.2 ng/L) compared with deceased patients (5.0 ng/L; P = .002). Survival analysis showed an increased survival in the highest n-oxPTH tertile compared with the lowest n-oxPTH tertile (χ(2), 14.3; P = .0008). Median survival was 1702 days in the highest n-oxPTH tertile, whereas it was only 453 days in the lowest n-oxPTH tertile. Multivariable-adjusted Cox regression showed that higher age increased odds for death, whereas higher n-oxPTH reduced the odds for death. Another model analyzing a subgroup of patients with intact PTH (iPTH) concentrations at baseline above the upper normal range of the iPTH assay (70 ng/L) revealed that mortality in this subgroup was associated with oxidized PTH but not with n-oxPTH levels. Conclusions: The predictive power of n-oxPTH and iPTH on the mortality of hemodialysis patients differs substantially. Measurements of n-oxPTH may reflect the hormone status more precisely. The iPTH-associated mortality is most likely describing oxidative stress-related mortality.
Journal of Clinical Endocrinology and Metabolism, 2013, Vol 98, Issue 12, p. 4744-51