ArticleSleep & breathing = Schlaf & Atmung2019
Lack of correlation between CSF glutamate levels and PSQI scores in heavy smokers.
Article in Sleep & breathing = Schlaf & Atmung, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers, 1 of them a synthesis that pooled it.
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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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.
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Who cites it
4 citing papers in PubMed, 1 synthesis or guideline pooled it, 6 citations in OpenAlex.
- Sleep, cerebrospinal fluid, and the glymphatic system: A systematic review.Sleep medicine reviews · 2022Pooled it
- Association between fibroblast growth factor 19 and depressive symptoms: the moderating role of smoking.Acta neuropsychiatrica · 2025Article
- Mediation Effect of Relaxin in Cerebrospinal Fluid on the Association Between Smoking and Sleep.Nature and science of sleep · 2025Article
- Fibroblast growth factor 21 associating with serotonin and dopamine in the cerebrospinal fluid predicts impulsivity in healthy subjects.BMC neuroscience · 2021Article
Corrections and comments
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Authors and funding
11 authors at 5 institutions in 1 country.
Funding
Abstract
objectiveGlutamate is an excitatory neurotransmitter in the central nervous system that participates in initiation and maintenance of sleep and wakefulness. The mechanisms involved occur in the brainstem, lateral hypothalamus, and basal forebrain. Our previous study suggested that higher levels of glutamate in cerebrospinal fluid (CSF) contributed to poorer sleep quality. Smoking has been shown to be harmful to sleep quality. In the present study, we recruited non-smokers and heavy smokers and measured the concentration of CSF glutamate in order to investigate the associations among smoking status, sleep quality, and CSF glutamate levels.
methodsWe recruited 147 men (n = 68 non-smokers, 30.31 ± 9.10 years; n = 79 heavy smokers, 34.54 ± 10.71 years). Glutamate concentrations in CSF were measured by spectrophotometry, and subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI).
resultsPSQI total scores were significantly higher in heavy smokers than that in non-smokers (p < 0.001). Glutamate concentrations in CSF were lower in heavy smokers than that in non-smokers (p < 0.001). CSF glutamate levels positively correlated with PSQI total scores in the non-smokers group (r = 0.313, p = 0.011, effect size = 0.324). No correlation was found between CSF glutamate levels and PSQI total scores in the heavy smokers group (p > 0.05). Multivariable linear regression analysis showed that years of smoking was contributed to the PSQI total scores (p = 0.008), and cigarettes smoked per day contributed to the decreased CSF glutamate levels in heavy smokers (p = 0.001).
conclusionPoorer subjective sleep quality and lower CSF glutamate concentrations were observed in the heavy smokers group than in the non-smokers group. In addition, lack of correlation was observed between CSF glutamate levels and PSQI scores in the heavy smokers.
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Registered trials
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