ALUMINUM AND SILICON IN THE HEMODIALYSIS POPULATION OF THE KINGDOM OFSAUDI-ARABIA

Objective: The correlation of intoxication by aluminum and by silicon in hemodialysis patients is not clear yet. We evaluated the levels of aluminum and silicon in serum of dialysis patients. Setting: Five dial ysis centers in the Kingdom of Saudi Arabia. Methods: The samples were obtained from 288 hemodialysis patients and 15 healthy controls. Of t hose patients in the study group 168 were males, and 120 were females. Their mean ages were 43 +/- 12.5 years with mean duration on hemodial ysis of 38 +/- 12 months. The acetate dialysate and bicarbonate dialys ate were used in 87% and 13% respectively. All the study centers used reverse osmosis (RO) to treat the water used in dialysis. There were 5 4% of patients on aluminum based phosphate binders. Results: The mean serum aluminum levels were 21.9 +/- 19.7 mu g/l. The serum aluminum le vels were significantly higher in one center compared to other centers (p < 0.0001). This may be due to the use of a cellulose acetate filte r in RO which did not retain aluminum. The mean level of serum silicon was 4647 +/- 2011 mu g/L. The serum levels of silicon were significan tly higher in centers which used cellulose acetate RO filter or high s ilicon levels in raw water, There were no correlations between levels of serum aluminum and silicon. Conclusion: That serum silicon and alum inum levels may be increased in hemodialysis patients due to increased content of these two elements either in drinking or dialysis water. H owever, their levels did not correlate with each other. Inadequate RO membranes to retain these elements may cause intoxication in dialysis patients. Regular monitoring of the quality of dialysis water is manda tory for these elements. Also, more studies about the effects of hyper siliconemia in dialysis patients are needed.