title: Urinary nitric oxide metabolites in children with celiac disease after long-term consumption of oats-containing gluten-free diet.
abstract: 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 nitrite/nitrate-rich foods close to the urine sampling.
  
  
  METHODS
  Morning urinary nitrite/nitrate 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 nitrite/nitrate level was 980 μM. The majority (70.2%) who consumed oats had low levels of urinary nitrite/nitrate, that is, <1400 μM, while 29.8% demonstrated high levels, that is, >1400 μM. Nitrite/nitrate-rich foods did not significantly influence the urinary concentrations.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Clinical and Experimental Medicine, Division of Paediatrics, Linköping University , Linköping , Sweden.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tapsas
authors.forename: Karin
authors.initials: K
authors.lastname: Fälth-Magnusson
authors.forename: Lotta
authors.initials: L
authors.lastname: Högberg
authors.forename: Tony
authors.initials: T
authors.lastname: Forslund
authors.forename: Tommy
authors.initials: T
authors.lastname: Sundqvist
authors.forename: Elisabet
authors.initials: E
authors.lastname: Hollén
mesh_terms: D000293:Adolescent; D018554:Avena; D002446:Celiac Disease / Q000178:diet therapy* / Q000652:urine; D002648:Child; D002675:Child, Preschool; D055050:Diet, Gluten-Free / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009566:Nitrates / Q000652:urine; D009569:Nitric Oxide / Q000652:urine*; D009573:Nitrites / Q000652:urine; D011379:Prognosis; D013997:Time Factors
chemical_list: D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide
keywords: celiac disease; gluten-free diet; oats; urinary nitrite/nitrate.