Unbalanced Trace Elements Found in Dialysis Patients

Dialysis patients have significantly different and abnormal blood concentrations of trace elements, which could explain dialysis morbidity, claims a new study.

Researchers from the University of Alberta (Edmonton, Canada) conducted a systematic review of 128 studies and investigated the trace element status of dialysis patients. The researchers included studies, which measured at least one of the following elements in whole blood, serum, or plasma: antimony, arsenic, boron, cadmium, chromium, cobalt, copper, fluorine, iodine, lead, manganese, mercury, molybdenum, nickel, selenium, tellurium, thallium, vanadium, and zinc. They then calculated differences between hemodialysis patients and controls using the differences in mean trace element level, divided by the pooled standard deviation.

The researchers found that the levels of cadmium, chromium, copper, lead, and vanadium were higher in the hemodialysis patients compared to controls, while levels of selenium, zinc, and manganese were lower. The researchers also found that studies examining any possible relation between trace element status and clinical outcomes were scarce. According to the researchers, experience with aluminum toxicity exemplifies the damage that uncontrolled elemental accumulation can cause. However, despite this recognition, the possibility that other trace elements may accumulate in patients with kidney failure and cause unrecognized chronic toxicity has received surprisingly little attention. The study was published ahead of print on May 19, 2009, in the open access journal BMC Medicine, a publication of BioMed Central.

"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,” said lead author Marcello Tonelli. "Aluminum accumulation led to serious toxicity in dialysis patients prior to the recognition that aluminum in dialysate and oral medications was responsible. Today, such aluminum-related toxicity is extremely rare.”

Trace elements, also known as micronutrients, are defined as a chemical element that is needed in minute quantities for the proper growth, development, and physiology of the organism. Cobalt, copper, chromium, fluorine, iron, iodine, manganese, molybdenum, selenium, and zinc are considered essential micronutrients. Nickel, tin, vanadium, silicon, and boron have recently been found as important micronutrients, whereas the status of arsenic, barium, bismuth, bromine, cadmium, germanium, gold, lead, lithium, mercury, rubidium, silver, strontium, titanium and zirconium is still being determined.

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