ArticleSleep & breathing = Schlaf & Atmung2021
The evaluation of serum tryptophan and kynurenine levels in patients with obstructive sleep apnea syndrome.
Article in Sleep & breathing = Schlaf & Atmung, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.
What it found
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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.
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Who cites it
6 citing papers in PubMed, 10 citations in OpenAlex.
- Disrupted glutamate-gaba balance in children with adenoid hypertrophy:a targeted metabolomic and clinical correlation study.European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · 2026Article
- Relationships of orexigenic and anorexigenic hormones with body fat distribution in patients with obstructive sleep apnea syndrome.European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · 2023Article
- Review
- Association of serum kynurenine/tryptophan ratio with poor glycemic control in patients with type2 diabetes.Journal of diabetes and metabolic disorders · 2021Article
- The evaluation of serum brain-derived neurotrophic factor and neurofilament light chain levels in patients with obstructive sleep apnea syndrome.Laryngoscope investigative otolaryngology · 2021Article
- The effect of obstructive sleep apnea on peripheral blood amino acid and biogenic amine metabolome at multiple time points overnight.Scientific reports · 2021Observational
Corrections and comments
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Authors and funding
5 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeThe kynurenine (Kyn) pathway may play a role in certain physiological functions such as behavior, sleep, thermoregulation, and pregnancy. Tryptophan (Trp) is oxidized with tryptophan 2,3-dioxygenase and indolamine 2,3-dioxygenase (IDO). Under normal conditions, hepatic kynurenine is a transcription factor and IDO expression in healthy tissues is very low. The ratio of Kyn to Trp can be used as an indicator to assess IDO activity. This study aimed to determine the relationship between Kyn/Trp ratio and obstructive sleep apnea syndrome (OSAS) disease activity.
methodsStudy participants were categorized in 3 groups: Group 1 included patients with mild OSAS, Group 2, patients with moderate to severe OSAS, and Group 3, individuals considered normal to serve as controls. The demographic characteristics of the patients were recorded. Apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) measurements were performed by diagnostic polysomnography (PSG). Trp and Kyn levels were determined by HPLC-UV method.
resultsGroup 1 included 30 patients (18 men) with mild OSAS; Group 2 included 42 patients (31 men) with moderate to severe OSAS; and Group 3 included 25 controls (13 men). While there was no statistically significant difference between the levels of tryptophan and kynurenine in the groups, a significant difference was found between the Kyn/Trp ratios. A significant correlation was observed in individuals with a body mass index less than 25 with the Kyn/Trp ratio. In individuals with mild OSAS, a significant correlation was observed between ODI and BMI. In individuals with moderate to severe OSAS, there was a significant correlation between ODI, AHI, and BMI.
conclusionIn this study, there was no relationship between OSAS disease severity and IDO activity as assessed by immunoreactivity via the Kyn/Trp pathway.
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