Abnormal levels of trace elements may explain dialysis morbidity. A systematic review published in the open access journal BMC Medicine has shown that, compared to healthy controls, dialysis patients have significantly different blood concentrations of trace elements.
Marcello Tonelli, from the University of Alberta, Canada, led a team of researchers who investigated the trace element status of dialysis patients in 128 studies. They found that levels of cadmium, chromium, copper, lead, and vanadium were higher and that levels of selenium, zinc and manganese were lower in the hemodialysis patients, compared with controls. Tonelli said, "Since both deficiency and excess of trace elements are potentially harmful yet amenable to therapy, the hypothesis that trace element status influences the risk of adverse clinical outcomes is worthy of investigation".
The researchers found that data examining any possible relation between trace element status and clinical outcomes are scarce. However, they point out that the nephrology community's experience with aluminium toxicity exemplifies the damage that uncontrolled elemental accumulation can cause, "Aluminium accumulation led to serious toxicity in dialysis patients prior to the recognition that aluminium in dialysate and oral medications was responsible. Today, such aluminium-related toxicity is extremely rare. However, the possibility that other trace elements may accumulate in patients with kidney failure and cause unrecognized chronic toxicity has received surprisingly little attention".
As well as the potentially toxic accumulation of some elements, this research highlights the reduced blood levels of others, including zinc. Tonelli points out that zinc supplementation is routinely used to correct deficiency in people from the general population, significantly reducing the risk of infection and all-cause death. He said, "Our data suggest that future studies should investigate the link between zinc or selenium status and clinical outcomes in dialysis patients, in whom the risk of infection is dramatically elevated compared to people with normal kidney function".
Notes to Editors
1. Trace elements in hemodialysis patients: A systematic review and meta-analysis
Marcello Tonelli, Natasha Wiebe, Brenda Hemmelgarn, Scott Klarenbach, Catherine Field, Braden Manns, Ravi Thadhani and John Gill for the Alberta Kidney Disease Network
BMC Medicine (in press)
During embargo, article available here: http://www.
After the embargo, article available at journal website: http://www.
Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.
Article citation and URL available on request at firstname.lastname@example.org on the day of publication
2. BMC Medicine - the flagship medical journal of the BMC series - publishes original research articles, commentaries and reviews in all areas of medical science and clinical practice. To be appropriate for BMC Medicine, articles need to be of outstanding quality, broad interest and special importance. BMC Medicine (ISSN 1741-7015) is indexed/tracked/covered by PubMed, MEDLINE, BIOSIS, CAS, Scopus, EMBASE, Current Contents, Thomson Reuters (ISI) and Google Scholar.
3. BioMed Central (www.biomedcentral.com) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.