Nitrogen metabolism and health of people with ileostomy

A comprehensive cross-sectional study was conducted on 60 ileostomy patients, 14 of whom had SBR. Compared to age- and sex-matched healthy controls, ileostomy patients had lower body mass index, lower lean mass and tended to be underweight. They were not only at risk of sodium depletion but this risk might also be associated with depleted body stores of calcium and magnesium. Ileostomy patients also had lower urinary nitrogen excretions due possibly to excess stomal nitrogen losses and/or the presence of urea-nitrogen salvage. When health status was assessed, ileostomy patients reported significant impairment in their physical, psychological and social well being. Despite these findings, however, haematological and biochemical blood indices were within normal limits of the general population suggesting that organ and biosynthetic functions are maintained at the expense of other metabolic processes. Studies on nitrogen balances and urea kinetics were also conducted in ileostomy patients with and without SBR so that potential changes in nitrogen metabolism could be examined. In free-living conditions, ileostomy patients had higher stool nitrogen losses and hence, higher nitrogen intakes compared to healthy controls. They were capable of urea-nitrogen salvage in the absence of the colon and were also able to maintain nitrogen balance. However, under metabolic duress created by a significant reduction in nitrogen intake, ileostomy patients, particularly those who had SBR, suffered significant reduction in nitrogen balance as they were not able to up-regulate urea-nitrogen salvage.