The relationship between insomnia and body temperatures.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing physiological mechanisms and clinical associations without systematic review methodology
PubMed 18603220 · doi:10.1016/j.smrv.2008.02.003
What was done
This narrative review synthesized literature evaluating associations between core body temperature circadian rhythms, thermoregulation, and specific subtypes of insomnia (sleep onset, early morning awakening, sleep maintenance, and combined insomnia), as well as chronobiological interventions such as timed bright light therapy.
What was found
The abstract reports no numerical data or effect sizes. Qualitatively, sleep onset insomnia is associated with a delayed temperature rhythm (responsive to morning bright light), early morning awakening is associated with a phase-advanced rhythm (responsive to evening bright light), sleep maintenance insomnia is associated with nocturnally elevated core body temperature, and combined onset/maintenance insomnia is associated with 24-hour elevated core body temperature. Impaired distal skin heat dissipation was not consistently supported across laboratory studies.
Why it matters
Mapping insomnia subtypes to distinct circadian phase shifts or 24-hour hyper-arousal patterns helps explain why targeted chronotherapies, like timed bright light exposure, can effectively treat specific sleep complaints.
Limits
As a narrative review, no systematic search methodology, study count, or participant sample size was reported in the abstract. Quantitative data are absent, evidence for impaired distal heat dissipation remains inconsistent, and findings from laboratory settings may not reflect real-world home environments.
Cited by
- context In order to wake up feeling refreshed and energized, human body temperature must increase by approximately 1 to 3 degrees.