ArticleOxidative medicine and cellular longevity2018
Low Serum Tryptophan Levels as an Indicator of Global Cognitive Performance in Nondemented Women over 50 Years of Age.
Article in Oxidative medicine and cellular longevity, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
27 citing papers in PubMed, 1 synthesis or guideline pooled it, 41 citations in OpenAlex.
- Kynurenine pathway dysregulation in cognitive impairment and dementia: a systematic review and meta-analysis.GeroScience · 2026Pooled it
- Neurochemical Insights into the Role of Tryptophan Metabolites and Kynurenine Pathway in Insomnia and its Psychological and Neurological Comorbidities.Molecular neurobiology · 2025Review
- Phenotypic and metabonomics studies of FMOs in C. elegans and their roles in lifespan extension.Metabolomics : Official journal of the Metabolomic Society · 2025Article
- Article
- Gut microbiota and the tryptophan-kynurenine pathway in anxiety: new insights and treatment strategies.Journal of neural transmission (Vienna, Austria : 1996) · 2025Review
- Essential amino acids and branched-chain amino acids are associated with skeletal muscle and inflammatory parameters in older age.Biogerontology · 2025Article
- The influence of physical fatigue on telephone-based neuropsychological test performance in COVID-19 survivors.European archives of psychiatry and clinical neuroscience · 2025Article
- Tryptophan-induced effects on the behavior and physiology of aging in tryptophan hydroxylase-2 heterozygous mice C57BL/6N.Veterinary world · 2025Article
- Metabolomic heterogeneity of ageing with ethnic diversity: a step closer to healthy ageing.Metabolomics : Official journal of the Metabolomic Society · 2024Article
- Cognitive impairment and changes of red blood cell components and serum levels of IL-6, IL-18, and L-tryptophan in methamphetamine abusers.American journal of neurodegenerative disease · 2023Article
- The Aging Process: A Metabolomics Perspective.Molecules (Basel, Switzerland) · 2022Article
- Tryptophan and serotonin levels as potent biomarkers in diabetes mellitus complications: a new approach of diagnostic role.Journal of diabetes and metabolic disorders · 2022Review
- Bioinformatic Analysis of Kynurenine Pathway Enzymes and Their Relationship with Glioma Hallmarks.Metabolites · 2022Article
- Safety, Tolerability, Pharmacokinetics and Initial Pharmacodynamics of a Subcommissural Organ-Spondin-Derived Peptide: A Randomized, Placebo-Controlled, Double-Blind, Single Ascending Dose First-in-Human Study.Neurology and therapy · 2022Article
- The Role of Tryptophan Metabolites in Neuropsychiatric Disorders.International journal of molecular sciences · 2022Review
- Microbial-derived metabolites as a risk factor of age-related cognitive decline and dementia.Molecular neurodegeneration · 2022Review
- Probiotic Releasing Angiotensin (1-7) in a Drosophila Model of Alzheimer's Disease Produces Sex-Specific Effects on Cognitive Function.Journal of Alzheimer's disease : JAD · 2022Article
- Kynurenine Pathway Metabolites in the Blood and Cerebrospinal Fluid Are Associated with Human Aging.Oxidative medicine and cellular longevity · 2022Article
- Molecular mechanisms of dietary restriction promoting health and longevity.Nature reviews. Molecular cell biology · 2022Review
- Integrated Multi-Omics for Novel Aging Biomarkers and Antiaging Targets.Biomolecules · 2021Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
15 authors at 5 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Aging is a physiological decline process. The number of older adults is growing around the world; therefore, the incidence of cognitive impairment, dementia, and other diseases related to aging increases. The main cellular factors that converge in the aging process are mitochondrial dysfunction, antioxidant impairment, inflammation, and immune response decline, among others. In this context, these cellular changes have an influence on the kynurenine pathway (KP), the main route of tryptophan (Trp) catabolism. KP metabolites have been involved in the aging process and neurodegenerative diseases. Although there are changes in the metabolite levels with age, at this time, there is no study that has evaluated cognitive decline as a consequence of Trp catabolism fluctuation in aging. The aim of this study was to evaluate the relation between the changes in Trp catabolism and cognitive impairment associated with age through KP metabolites level alterations in women over 50 years of age. Seventy-seven nondemented women over 50 years old were examined with a standardized cognitive screening evaluation in Spanish language (Neuropsi), Beck anxiety inventory (BAI), and the geriatric depression scale (GDS). Also, serum levels of Trp, kynurenine (Kyn), kynurenic acid (KYNA), and 3-hydroykynurenine (3-HK) and the glutathione ratio (GSH/GSSG) were measured. Results showed a negative correlation between age and Trp levels and a positive correlation between age and KYNA/Trp and 3-HK/Trp ratios. The level of cognitive impairment showed a significant positive association with age and with kynurenine pathway activation and a significant negative correlation with Trp levels. The GSH/GSSG ratio correlated positively with Trp levels and negatively with Kyn/Trp and 3-HK/Trp ratios. The depression score correlated negatively with Trp and positively with the 3-HK/Trp ratio. We concluded that KP activation increases with age and it is strongly associated with the level of cognition performance in nondemented women over 50 years of age.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.