Profile of serum silicon in aluminium-overloaded patients on regular haemodialysis treatment

Abstract

Serum concentrations of silicon and aluminium have been compared in patients with end-stage renal disease on haemodialysis treatment. Both serum silicon and aluminium were elevated in comparison with non-renal failure healthy controls and gave an overall significant but relatively weak positive correlation. The silicon concentrations observed however were not related to the duration of the disease or the number of years on dialysis. To investigate a possible chemical interrelationship between the two elements two groups of patients with or without aluminium overload, as determined by a low dose desferrioxamine (DFO) test, were studied. During the DFO test blood samples were taken pre-dialysis then 4, and 48 h after dialysis to establish the effect of dialysis on silicon and aluminium. Serum silicon fell immediately after dialysis whereas aluminium increased in all patients and particularly in the aluminium overload group. Thus, silicon is more freely diffusible than the aluminium–desferal complex and any chemical association between the two individual elements would appear to be relatively weak. However, serum silicon remained significantly higher both before and immediately after dialysis in the aluminium-overload group. The observations indicate that silicon and aluminium show some evidence of association in serum however the exact chemical nature, possibly as an aluminosilicate, needs further investigation.