Component
Circulating FGF21 concentration
Circulating FGF21 concentration. Species, exposure and limitations are retained in each linked claim.
1 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
Where it participates (unsigned role)
Cold exposure increased circulating irisin and FGF21, with irisin secretion induced in proportion to shivering intensity and of similar magnitude to exercise-stimulated secretion.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/cold-research/24506871.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610", "start_char": 0, "end_char": 1149, "text_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610"}
- experimental_model
- Human cold exposure with circulating myokine measurement and human adipocyte treatment
- exposure
- Cold exposure sufficient to induce shivering; FNDC5 and FGF21 treatment of human adipocytes
- limitations
- The proportionality to shivering intensity is the mechanistic link. Depot-specific adipocyte responses mean this is not a uniform browning effect.
- nutrient_topic
- Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
- organism
- Human
- plain_language
- Shivering muscle releases the same messenger exercising muscle does, in proportion to how hard it shivers.
- primary_references
- [cold-p24506871] Irisin and FGF21 are cold-induced endocrine activators of brown fat function in humans. (2014). https://pubmed.ncbi.nlm.nih.gov/24506871/ DOI: 10.1016/j.cmet.2013.12.017
- tissue_or_cell_type
- Skeletal muscle and adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 481–492
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human cold exposure with circulating myokine measurement and human adipocyte treatment · source_derived_draft · unverified_draft
### cold-irisin-shivering Cold exposure increased circulating irisin and FGF21, with irisin secretion induced in proportion to shivering intensity and of similar magnitude to exercise-stimulated secretion. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Shivering muscle releases the same messenger exercising muscle does, in proportion to how hard it shivers. organism: Human tissue_or_cell_type: Skeletal muscle and adipose tissue experimental_model: Human cold exposure with circulating myokine measurement and human adipocyte treatment limitations: The proportionality to shivering intensity is the mechanistic link. Depot-specific adipocyte responses mean this is not a uniform browning effect. exposure: Cold exposure sufficient to induce shivering; FNDC5 and FGF21 treatment of human adipocytes evidence_span: {"source_cache": "artifacts/cold-research/24506871.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610", "start_char": 0, "end_char": 1149, "text_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610"} [cold-p24506871] Irisin and FGF21 are cold-induced endocrine activators of brown fat function in humans. (2014). https://pubmed.ncbi.nlm.nih.gov/24506871/ DOI: 10.1016/j.cmet.2013.12.017
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.