Red blood cell and serum selenium concentrations as influenced by age and selected diseases

Red blood cell and serum selenium concentrations were investigated to determine normal concentrations for our geographic area and if potential differences existed in patients with selected diagnoses (hepatic, renal, malignant, and chronic diseases). Selenium was quantified in samples of red blood cells, serum and urine by neutron activation analysis. The results were analyzed by comparing 1) pooled data from all ages for each disease with normal values, and 2) normal values with age-matched patients in each disease category. Decreases in red blood cell selenium concentrations (P less than 0.05) occurred in normal subjects over 60 years of age without concurrent significant decreases in serum selenium. Although differential results were noted in age-matched groups, overall results showed that decreased concentrations of selenium in both red cells and in serum occurred with alcoholic cirrhosis, malignancies, and chronic renal failure (P less than 0.025). Red blood cell selenium concentrations also were decreased in patients with stable chronic disease. Decreased serum selenium concentrations were positively correlated with albumin concentrations in patients with cirrhosis. There was no correlation between serum selenium and bilirubin concentrations in patients with liver disease or between serum selenium and creatinine concentrations in patients with chronic renal failure whose urinary excretion of selenium was far below control levels.