THE METABOLISM OF [SE-75]SELENITE IN PATIENTS WITH SHORT-BOWEL SYNDROME

Background: Patients on home parenteral nutrition (HPN) require signif icantly higher amounts of selenium compared with controls. The purpose of the present study was to investigate if selenium deficiency of pat ients with short bowel syndrome is caused by selenium malabsorption or by excessive intestinal or renal loss. Methods: The metabolism of [Se -75]selenite was investigated in eight selenium-depleted short bowel p atients on HPN and in six control subjects. The isotope was given oral ly, and in a subsequent study as bolus injection or as 12-hour IV infu sion. Results: The fractional intestinal absorption of selenium was si gnificantly reduced in the patients (2% to 58%, median 20%) when compa red with the reference group (79% to 91%, median 82%) (p <.001). Withi n the group of patients we found a positive significant correlation be tween fractional selenium absorption and the length of the remaining s mall intestine (r = 0.95, p <.05). After parenteral [Se-75]selenite ad ministration, the patients showed a significantly higher fecal loss an d a significantly reduced urinary excretion of Se-75 when compared wit h the controls. Bolus injection vs 12-hour infusion of [Se-75]selenite did not affect the cumulative fecal or urinary Se-75 excretion in the HPN patients. Conclusions: Reduced intestinal selenium absorption is probably the most important cause of the selenium deficiency reported in patients with short bowel syndrome, but increased endogenous intest inal selenium loss and low selenium intake may also contribute. Despit e the renal counterregulation, which results in a low urinary selenium excretion, HPN patients need a supply of selenium with their parenter al nutrition.