title: Increased nitric oxide in exhaled air after intake of a nitrate-rich meal.
abstract: Exhaled and nasal NO (ENO, NNO) have been suggested as markers for inflammation in lower and upper respiratory tract respectively. It is still unknown how a number of factors, apart from airway inflammation, can influence NO levels. The aim of this study was to determine the effect of a nitrate-rich meal on ENO and NNO. Sixteen healthy subjects were observed during 1 week on normal diet before a nitrate-restricted diet was introduced in the next. On day 3 of the second week they were made to ingest a nitrate rich meal. ENO, NNO, plasma nitrate and plasma L-arginine were followed before the meal and afterwards for 3 h. ENO and NNO as well as plasma nitrate and plasma L-arginine were significantly elevated after the nitrate-rich meal. The median maximal increase of ENO and NNO was 47% and 13% respectively. We found a moderate but significant correlation between the rise in plasma nitrate and ENO (r(s)=0.57, P=0.027) but none between plasma nitrate and NNO (r(s)=-0.02, P=0.95). As nitrate in the diet seems to substantially influence the levels of ENO it is important either to restrict or register the intake of nitrate-rich food prior to measuring ENO.
authors.affiliation: Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Göteborg, Sweden. anna-carin.olin@ymk.gu.se
authors.forename: A C
authors.initials: AC
authors.lastname: Olin
authors.forename: A
authors.initials: A
authors.lastname: Aldenbratt
authors.forename: A
authors.initials: A
authors.lastname: Ekman
authors.forename: G
authors.initials: G
authors.lastname: Ljungkvist
authors.forename: L
authors.initials: L
authors.lastname: Jungersten
authors.forename: K
authors.initials: K
authors.lastname: Alving
authors.forename: K
authors.initials: K
authors.lastname: Torén
mesh_terms: D000328:Adult; D001120:Arginine / Q000097:blood; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests; D005260:Female; D006801:Humans; D008297:Male; D009566:Nitrates / Q000008:administration & dosage* / Q000097:blood; D009569:Nitric Oxide / Q000032:analysis*; D019518:Postprandial Period; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D009566:Nitrates; D009569:Nitric Oxide; D001120:Arginine