Research Viewpoints Laboratory Parameters and Dialysis Modality

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Soohoo M., Obi Y., Rivara M.B., Adams S.V., Lau W.L., Rhee C.M., Kovesdy C.P., Kalantar-Zadeh K., Arah O.A., Mehrotra R., Streja E. T: Comparative Effectiveness of Dialysis Modality on Laboratory Parameters of Mineral Metabolism. Am J Nephrol DOI 10.1159/000521508

The comparative effectiveness of various modalities of dialysis in patients with kidney failure has long been controversial, in large part due to the paucity of long-term randomized clinical trials. Soohoo and coworkers sought to examine the laboratory biomarkers of chronic kidney disease-metabolic bone disease (CKD-MBD) in a large cohort of patients receiving a variety of dialysis modalities, using an administrative database accumulated between 2002 and 2011. The analysis was conducted by inverse-weighted marginal structural modelling.

Using conventional thrice weekly in-center hemodialysis as the comparator, patients with nocturnal in-center hemodialysis had lower PTH and phosphate levels, whereas patients undergoing peritoneal or home hemodialysis had higher levels of PTH but lower levels of phosphate. Serum calcium and alkaline phosphatase levels showed no systematic differences that were modality dependent.

This study was focused on laboratory parameters commonly used as biomarkers for CKD-MBD. As such, no data is provided concerning important outcome measures, such as mortality, fractures, and hospitalization. In addition, dietary measures, timing of blood sampling, and vitamin D status were not included. Only phosphate binder and oral/IV vitamin D use were analyzed.

This study is primarily hypothesis generating and is likely confounded by many unmeasured variables. Whether it indicates that modality selection is an important and independent determinant in the risk of developing CKD-MBD remains uncertain, but is deserving of further study.