title: Maternal tryptophan and kynurenine pathway metabolites and risk of preeclampsia.
abstract: OBJECTIVE
  To estimate the association of maternal plasma concentrations of tryptophan and six kynurenine pathway metabolites with the risk of preeclampsia.
  
  
  METHODS
  The study was based on a subsample of 2,936 pregnant women who delivered singleton neonates in the Norwegian Mother and Child Cohort Study in 2002-2003. Maternal blood plasma was obtained at approximately gestational week 18 and was measured for tryptophan, kynurenine, kynurenic acid, anthranilic acid, 3-hydroxykynurenine, xanthurenic acid, and 3-hydroxyanthranilic acid.
  
  
  RESULTS
  Of the 2,936 pregnant women included in this study, 116 (4.0%, 95% confidence interval [CI] 3.2-4.7) had preeclampsia subsequently diagnosed. The prevalence of preeclampsia was significantly higher among women with plasma kynurenic acid concentrations greater than the 95th percentile than among those with concentrations in the 25th-75th percentile (11.0% compared with 3.3%, P<.001; adjusted odds ratio 3.6, 95% CI 1.9-6.8). This association was significantly stronger in women with prepregnancy body mass index of 25 or more (P for interaction=.03; 20.4% compared with 4.2%; P<.001). No statistically significant associations of preeclampsia with other tryptophan metabolites were found.
  
  
  CONCLUSIONS
  Elevated maternal plasma kynurenic acid concentrations in early pregnancy are associated with a substantial increased risk of preeclampsia in obese women.
  
  
  METHODS
  II.
authors.affiliation: Department of Heart Disease, Haukeland University Hospital, Bevital AS, Norway. roy.miodini.nilsen@helse-bergen.no
authors.forename: Roy M
authors.initials: RM
authors.lastname: Nilsen
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Bjørke-Monsen
authors.forename: Oivind
authors.initials: O
authors.lastname: Midttun
authors.forename: Ottar
authors.initials: O
authors.lastname: Nygård
authors.forename: Eva R
authors.initials: ER
authors.lastname: Pedersen
authors.forename: Arve
authors.initials: A
authors.lastname: Ulvik
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
authors.forename: Håkon K
authors.initials: HK
authors.lastname: Gjessing
authors.forename: Stein Emil
authors.initials: SE
authors.lastname: Vollset
authors.forename: Per Magne
authors.initials: PM
authors.lastname: Ueland
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007737:Kynurenine / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*; D009664:Norway / Q000453:epidemiology; D050177:Overweight / Q000097:blood / Q000378:metabolism; D011225:Pre-Eclampsia / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism*; D011247:Pregnancy; D015995:Prevalence; D012306:Risk; D014364:Tryptophan / Q000097:blood / Q000378:metabolism*; D055815:Young Adult
chemical_list: D007737:Kynurenine; D014364:Tryptophan