ArticleThe Journal of nutrition2015
Tryptophan catabolism and vitamin B-6 status are affected by gender and lifestyle factors in healthy young adults.
Article in The Journal of nutrition, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers.
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Who cites it
27 citing papers in PubMed, 53 citations in OpenAlex.
- Effectiveness of a Saffron and Withania Supplement on Mood in Women With Mild-to-Moderate Anxiety During the COVID-19 Lockdown.Depression and anxiety · 2024Trial
- The potential role of kynurenine pathway and inflammation in pediatric obsessive-compulsive disorder with and without major depressive disorder comorbidity.Journal of neural transmission (Vienna, Austria : 1996) · 2026Article
- Differential alterations in peripheral tryptophan pathways in methamphetamine versus MDMA users are linked to their contrasting psychiatric symptoms.Translational psychiatry · 2026Article
- Metabolomics and Human Health: Progress, Insights, Challenges and the Concept of a Healthy Metabolome.Biomolecules · 2026Review
- The role of oral contraceptive use in associations of concussion history with kynurenine pathway metabolites, inflammation, and psychological symptoms in female athletes.Brain, behavior, & immunity - health · 2026Article
- Tryptophan degradation as a systems phenomenon in inflammation - an analysis across 13 chronic inflammatory diseases.EBioMedicine · 2024Article
- Sex- and suicide-specific alterations in the kynurenine pathway in the anterior cingulate cortex in major depression.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2024Article
- Article
- Changes in tryptophan breakdown associated with response to multimodal treatment in depression.Frontiers in psychiatry · 2024Article
- Lower levels of the neuroprotective tryptophan metabolite, kynurenic acid, in users of estrogen contraceptives.Scientific reports · 2023Article
- Serum concentrations of amino acids and tryptophan metabolites are affected by consumption of a light breakfast: a clinical intervention study in adults with overweight or obesity.BMC nutrition · 2023Article
- Associations of Parameters of the Tryptophan-Kynurenine Pathway with Cardiovascular Risk Factors in Hypertensive Patients.Nutrients · 2023Article
- Changes in Tryptophan-Kynurenine Metabolism in Patients with Depression Undergoing ECT-A Systematic Review.Pharmaceuticals (Basel, Switzerland) · 2022Review
- Association of plasma kynurenine pathway metabolite concentrations with metabolic health risk in prepubertal Asian children.International journal of obesity (2005) · 2022Article
- The Kynurenine Pathway in Obese Middle-Aged Women with Normoglycemia and Type 2 Diabetes.Metabolites · 2022Article
- The Kynurenine Pathway Metabolites in Cord Blood Positively Correlate With Early Childhood Adiposity.The Journal of clinical endocrinology and metabolism · 2022Article
- Reliability of a dried urine test for comprehensive assessment of urine hormones and metabolites.BMC chemistry · 2021Article
- Untargeted metabolomic analysis in non-fasted diabetic dogs by UHPLC-HRMS.Metabolomics : Official journal of the Metabolomic Society · 2019Article
- The 677C→T variant of MTHFR is the major genetic modifier of biomarkers of folate status in a young, healthy Irish population.The American journal of clinical nutrition · 2018Article
- Alterations in serum kynurenine pathway metabolites in individuals with high neocortical amyloid-β load: A pilot study.Scientific reports · 2018Article
Corrections and comments
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Authors and funding
13 authors at 8 institutions in 4 countries.
Funding
Abstract
backgroundAbnormalities of tryptophan (Trp) metabolism through the kynurenine (Kyn) pathway have been reported in various diseases; however, nutritional and lifestyle factors that affect this pathway in healthy individuals are not well documented.
objectiveOur aim was to examine the effect of vitamin B-6 status and lifestyle factors including the use of vitamin B-6 supplements, alcohol, smoking, and oral contraceptives on Trp and its Kyn metabolites in a cohort of 2436 healthy young adults aged 18-28 y.
methodsAnthropometric and lifestyle data were collected by questionnaire. Participants provided blood samples for analysis of Trp, Kyn, anthranilic acid, kynurenic acid (KA), 3-hydroxykynurenine (HK), 3-hydroxyanthranilic acid (HAA), and xanthurenic acid (XA). Vitamin B-6 species were also measured.
resultsSerum Trp metabolites were 10-15% higher among men (n = 993) compared with women (n = 1443; P < 0.0001), except for HK and XA. In all participants, serum Trp was positively associated with plasma pyridoxal 5'-phosphate (PLP; r = 0.28, P < 0.0001), reaching a plateau at PLP concentrations of ∼83 nmol/L. HK was inversely associated with PLP (r = -0.14, P < 0.01). Users of vitamin B-6 supplements (n = 671) had 6% lower concentrations of HK than nonusers (n = 1765; P = 0.0006). Oral contraceptive users (n = 385) had lower concentrations of KA (20.7%) but higher XA (24.1%) and HAA (9.0%) than did nonusers (n = 1058; P < 0.0001). After adjustment for gender and other lifestyle variables, XA concentrations were 16% higher in heavy drinkers (n = 713) than in never or occasional drinkers (n = 975; P = 0.0007). Concentrations of 2 other essential amino acids, methionine and arginine, also were positively associated with serum Trp (r = 0.65 and 0.33, respectively; P < 0.0001).
conclusionsIn this population of healthy young adults, gender has the largest influence on serum Kyn metabolite concentrations. The significant covariance of Trp with unrelated amino acids suggests that protein intake may be an important consideration in evaluating Kyn metabolism.
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