Iron Profile Differs for Hemodialysis Patients With ADPKD
Investigators found a U-shaped curve of mortality against ferritin/TSAT levels in patients without autosomal dominant polycystic kidney disease, but not in those with the disease.
The need for iron supplementation likely varies for hemodialysis (HD) patients with and without autosomal dominant polycystic kidney disease (ADPKD).
Investigators led by Yen-Chung Lin, MD, of Taipei Medical University Hospital, identified and compared iron profiles from 1346 ADPKD and 82,873 non-ADPKD patients using Taiwan's Renal Registry Data System. For patients without ADPKD, time-averaged ferritin levels exceeding 800 ng/mL or transferrin saturation (TSAT) levels exceeding 50% was associated with a significant 52% and 46% greater risk for 3-year all-cause mortality, respectively, compared with those with normal iron indices, according to results in the Journal of Renal Nutrition. Multivariate Cox regression analyses adjusted for age, comorbidities such as diabetes, and relevant laboratory parameters.
In addition, investigators observed a U-shaped survival curve as ferritin/TSAT levels rose from low to high in patients without ADPKD, but not in those with the disease. Use of erythropoiesis-stimulating agents (ESA) could not explain the difference.
In patients without ADPKD, this finding is consistent with the KDOQI (Kidney Disease Outcomes Quality Initiative) or KDIGO (Kidney Disease: Improving Global Outcomes) guidelines, which recommend the maintenance of serum ferritin levels in patients on dialysis in the 100 to 500 ng/mL range, according to Dr Lin and his collaborators. ADPKD patients have higher endogenous erythropoietin levels, so their recommended iron indices for HD patients may differ, they noted.
The investigators concluded that “this nationwide population-based cohort study showed that tight control of iron supplementation in patients without PKD who are undergoing HD is reasonable. However, in patients with PKD, regardless of the use of ESA agents to maintain hemoglobin levels, the iron profile had no significant impact on mortality.”
Yeh SC, Lin YC, Hong YC, et al. Different effects of iron indices on mortality in patients with autosomal dominant polycystic kidney disease after long-term hemodialysis: A nationwide population-based study. J Ren Nutr. DOI:10.1053/j.jrn.2018.11.004