Urinary nitric oxide metabolites in children with celiac disease after long-term consumption of oats-containing gluten-free diet

摘要

Objective. Oats are accepted in the gluten-free diet (GFD) for children with celiac disease (CD). Some reports have indicated, however, that not all celiac patients tolerate oats. We have previously shown that some children still have high levels of urinary nitric oxide (NO) metabolites as markers of intestinal inflammation after 1 year on GFD with oats. In this study, we measured urinary NO metabolites in CD children who had been consuming oats-containing GFD for an extended, 2-6-year period, also taking into consideration ordinary consumption of nitriteitrate-rich foods close to the urine sampling. Materials and Methods. Morning urinary nitriteitrate concentrations were measured in 188 pediatric CD patients. A questionnaire was used to elucidate factors possibly affecting the urinary levels, for example, dietary factors, asthma, or urinary tract infection. Results. Oats were consumed by 89.4% of the patients for a median time of 3 years. The median nitriteitrate level was 980 mu M. The majority (70.2%) who consumed oats had low levels of urinary nitriteitrate, that is, < 1400 mu M, while 29.8% demonstrated high levels, that is, > 1400 mu M. Nitriteitrate-rich foods did not significantly influence the urinary concentrations. Conclusion. The urinary levels of NO metabolites revealed two subpopulations, one with high and one with low levels. The high levels could be possibly due to poor adherence to the GFD, sensitivity to oats, or some unknown factor(s). Nitrate-rich foods, asthma, or urinary tract infection did not affect the result. The elevated levels of NO metabolites could indicate mucosal inflammation and pinpoint the need of careful follow-up of children on oats-containing GFD.