Evidence for chromium imbalance in dialyzed uremic patients with chronic renal failure

Abstract

The problem of diseases caused by trace element imbalance in dialyzed uremic patients is mainly related to aluminium toxicity. During hemodialysis accumulation of this element in the tissues of the patients can occur, resulting in clinical disorders such as encephalopathy. The dramatic example of the aluminium suggests to investigate if other trace element imbalances could be responsible for some of the symptomathology in chronic dialysis patients. The objectives of this work, carried out by neutron activation analysis (NAA) are : (i) to give evidence for chromium imbalance in dialyzed uremic patients; (ii) to identify possible sources responsible for the chromium disturbances. In particular: (i) NAA of the serum of dialyzed patients shows Cr concentrations up to 1020 ppb which are obviously higher in comparison to the mean value of 0.15 ppb for normal subjects. Amounts of Cr of 8500 and 445 ppb have been observed in autoptic brain tissues from two dialysis patients. These amounts can be considered “abnormal” considering that the typical brain Cr level in normal subjects is 10 ppb. These results suggest the possibility for Cr to be significantly accumulated in the body of uremic patients submitted to regular hemodialysis. (ii) NAA of the salts used for the preparation of the dialysis fluid shows wide variations of the Cr content, from 2.8 to 6830 ppb, leading to an estimated contribution of Cr to the dialysate up to 3.5 ppb. However, Cr levels of 62 and 145 ppb were experimentally determined in two dialysis fluids. This suggests that significant amounts of Cr would be introduced into the dialysis fluid by sources other than the salts, e.g. dialysis equipment. Analysis of Cr in aluminium-containing phosphate gels (of the order of ppm) indicates that these drugs may represent an additional source of Cr to the uremic patients. Additional studies are necessary to assess the toxicological significance of the abnormal levels of Cr observed in the tissues of the dialyzed patients.