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SYSTEMATIC REVIEW article

Front. Aging Neurosci.
Sec. Neurocognitive Aging and Behavior
Volume 16 - 2024 | doi: 10.3389/fnagi.2024.1465457
This article is part of the Research Topic Neuropsychiatric symptoms and cognitive impairment View all 15 articles

Association of Trimethylamine Oxide and its Precursors with Cognitive Impairment: a Systematic Review and Meta-analysis

Provisionally accepted
Caiyi Long Caiyi Long Zihan Li Zihan Li Haoyue Feng Haoyue Feng Ya-yi Jiang Ya-yi Jiang Pu Yueheng Pu Yueheng Jiajing Tao Jiajing Tao Rensong Yue Rensong Yue *
  • Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China

The final, formatted version of the article will be published soon.

    Abstract: Objectives: The role of trimethylamine oxide (TMAO) in patients with cognitive impairment remains controversial. This study aimed to assess the association between TMAO and its precursors and the prevalence of cognitive impairment. Methods: PubMed, Embase, and Web of Science databases were searched for studies that met the inclusion criteria from their inception to 14 September 2024, and references were manually searched to identify any additions. Odds ratio (OR) was assessed by random-effects modelling, subgroup analyses to identify potential sources of heterogeneity, and the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) Inventory for qualitative evaluation. Results: Nine studies involving 82,246 participants were included in the analysis. Meta-analyses suggested that elevated TMAO levels were strongly associated with an increased risk of cognitive impairment (OR: 1.39, 95% confidence interval [95%CI]: 1.09-1.77, P < 0.05, I2:60%), and consistent results were obtained across all subgroups examined and sensitivity analyses. However, in the TMAO dose-response meta-analysis and TMAO precursor meta-analyses, the results were not significantly different (dietary choline: OR: 0.93, 95%CI: 0.78-1.10, P = 0.385, I2:68%, plasma choline: OR: 0.65, 95%CI: 0.41-1.02, P = 0.063, I2:76%, plasma betaine: OR: 0.74, 95%CI: 0.52-1.05, P = 0.094, I2:61%). Conclusions: We found that high TMAO concentrations were positively associated with the risk of cognitive impairment. TMAO is expected to be a potential risk predictor and therapeutic target for cognitive impairment. However, more high-quality studies are needed to further investigate the dose relationship between circulating TMAO concentrations and cognitive impairment.

    Keywords: Trimethylamine oxide, TMAO, circulating concentration, cognitive impairment, Meta-analysis

    Received: 31 Jul 2024; Accepted: 23 Sep 2024.

    Copyright: © 2024 Long, Li, Feng, Jiang, Yueheng, Tao and Yue. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Rensong Yue, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.