Tier 2 — strong

Short and long-term variation of plasma glycine betaine concentrations in humans

Michael Lever, Peter C M Sizeland, Christopher M Frampton, Stephen T Chambers
Clinical biochemistry 2004 37(3):184-190

Bibliography

PubMed
PMID 14972639
DOI
10.1016/j.clinbiochem.2003.11.004
Funding
Funding was not specified in the indexed record or accessible funding metadata.
Competing interests
A competing-interest declaration was not available in the indexed record or accessible disclosure metadata.

Study snapshot

DesignRepeated-measure physiology study
ModelHuman participants
SampleHealthy volunteers across three protocols
InterventionMeasured betaine status and related metabolites; no randomized TMG treatment
DurationAcute fluid challenges, 15-day protocol and 3-year repeat sampling
EndpointsBetaine homeostasis; Fluid balance

What the study showed, in plain terms

Published in 2004, this source examined human observational and biomarker research. Design: Repeated-measure physiology study. Sample/model: Healthy volunteers across three protocols. The exposure or intervention was Measured betaine status and related metabolites; no randomized TMG treatment. Follow-up or treatment period: Acute fluid challenges, 15-day protocol and 3-year repeat sampling.

Circulating glycine betaine showed individual stability despite fluid-balance challenges, unlike dietary proline betaine.

Observational exposure analysis: residual confounding and reverse causation remain possible. Associations do not establish that betaine supplementation causes the same outcome.

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Key findings

  • Circulating glycine betaine showed individual stability despite fluid-balance challenges, unlike dietary proline betaine.
  • The recorded outcome domains were Betaine homeostasis; Fluid balance.
  • The result applies to the tested exposure: Measured betaine status and related metabolites; no randomized TMG treatment; Acute fluid challenges, 15-day protocol and 3-year repeat sampling.

What this study can and cannot tell us

  • Observational exposure analysis: residual confounding and reverse causation remain possible. Associations do not establish that betaine supplementation causes the same outcome.
  • An individual controlled trial must be interpreted alongside its comparator, sample size, endpoint selection and independent replication. It does not validate a different commercial formulation or a general longevity claim.
  • Source basis: Indexed abstract and bibliographic data. Missing method details, funding information or participant denominators are not inferred.

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Editorial review

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Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology