Loneliness: An Immunometabolic Syndrome.
Level 5 - mechanism / opinion, no new human data
Narrative review proposing a conceptual framework without new empirical data or systematic review methodology.
PubMed 34831917 · doi:10.3390/ijerph182212162
What was done
This narrative review synthesized literature linking the psychological construct of loneliness to physiological pathways, proposing a theoretical framework that defines loneliness as an "immunometabolic syndrome" driven by poor health behaviors, heightened stress responses, and impaired physiological repair mechanisms.
What was found
The abstract reports no numerical data, effect sizes, or study counts. It qualitatively summarizes associations between loneliness and alterations in inflammatory cytokines, growth factors, acute-phase reactants, chemokines, immunoglobulins, viral and vaccine antibody responses, immune cell activity, stress circuitry, glycemic control, lipid metabolism, body composition, metabolic syndrome, cardiovascular function, cognitive function, and mental health.
Why it matters
It provides a unifying conceptual model framing loneliness not merely as a subjective psychosocial state, but as a multisystem disorder characterized by coordinated immunometabolic dysregulation.
Limits
The abstract describes a non-systematic narrative review with no search methodology, no quantitative synthesis, and no evaluation of study quality or confounding factors. Causal relationships between loneliness and biological markers cannot be confirmed from this framework.
Cited by
- supports Loneliness causes spikes in bloodstream cortisol that compromise cardiovascular functioning and the immune system, leading to increased illness and shortened lifespan.