Geographic factors and plasma selenium in uremia and dialysis.

The importance of selenium (Se) as an essential trace element for man has been increasingly recognized. Blood Se levels in chronic uremic patients are frequently reported to be lower than in controls. Definitive determination of the Se status in uremic patients, however, is hampered by the wide range of blood Se content in humans from different parts of the world. The present study was designed to assess and compare the Se status in two European populations from Rostock (Germany) and Chieti (Italy). Plasma Se levels were evaluated in healthy controls, chronic renal failure nondialyzed patients (CRF) and hemodialysis patients (HD). All Se determinations were performed in a single laboratory. The Se concentration was significantly higher (p < 0.005) in Italian healthy controls than in German healthy controls. In contrast, Se levels were similar in both CRF and HD patients from both cities. In both countries, the Se concentration in CRF and HD patients was significantly lower (p < 0.001) than in their corresponding controls, but no difference between CRF and HD was found. CRF and HD patients from the two countries showed quite similar laboratory and anthropometric data. In CRF patients in Chieti, a significant (p < 0.05) negative correlation between plasma Se and serum creatinine was found. In both HD groups, the length of time on HD and type of membrane dialyzer used did not influence the Se status. A significant positive correlation (p < 0.01) between Se levels and the protein catabolic rate was found in both HD groups. Uremia seems to be a strong factor which overrules the difference in Se levels that is present in healthy adults from different European countries. Uremia in itself may influence and level the Se concentration in patients with geographic diversity.