Tick-Tock Consider the Clock: The Influence of Circadian and External Cycles on Time of Day Variation in the Human Metabolome—A Review

Hancox, Thomas PM, Skene, Debra J, Dallmann, Robert and Dunn, Warwick B ORCID: 0000-0001-6924-0027
(2021) Tick-Tock Consider the Clock: The Influence of Circadian and External Cycles on Time of Day Variation in the Human Metabolome—A Review. Metabolites, 11 (5). p. 328.

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<jats:p>The past decade has seen a large influx of work investigating time of day variation in different human biofluid and tissue metabolomes. The driver of this daily variation can be endogenous circadian rhythms driven by the central and/or peripheral clocks, or exogenous diurnal rhythms driven by behavioural and environmental cycles, which manifest as regular 24 h cycles of metabolite concentrations. This review, of all published studies to date, establishes the extent of daily variation with regard to the number and identity of ‘rhythmic’ metabolites observed in blood, saliva, urine, breath, and skeletal muscle. The probable sources driving such variation, in addition to what metabolite classes are most susceptible in adhering to or uncoupling from such cycles is described in addition to a compiled list of common rhythmic metabolites. The reviewed studies show that the metabolome undergoes significant time of day variation, primarily observed for amino acids and multiple lipid classes. Such 24 h rhythms, driven by various factors discussed herein, are an additional source of intra/inter-individual variation and are thus highly pertinent to all studies applying untargeted and targeted metabolomics platforms, particularly for the construction of biomarker panels. The potential implications are discussed alongside proposed minimum reporting criteria suggested to acknowledge time of day variation as a potential influence of results and to facilitate improved reproducibility.</jats:p>

Item Type: Article
Uncontrolled Keywords: circadian rhythms, diurnal rhythms, metabolomics, metabolite rhythms, blood, urine, saliva, breath, skeletal muscle
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology
Depositing User: Symplectic Admin
Date Deposited: 18 Jan 2022 09:34
Last Modified: 18 Jan 2023 21:15
DOI: 10.3390/metabo11050328
Open Access URL: https://doi.org/10.3390/metabo11050328
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3147091