Circadian temperature rhythms in young adult and aged men.
Level 3 - non-randomized controlled study
Non-randomized cross-sectional comparative study between age cohorts
PubMed 3960269 · doi:10.1016/0197-4580(86)90146-6
What was done
Core body temperatures were continuously recorded for 14 to 24 hours in 10 healthy young adult men and 8 healthy aged men using rectal thermometers and analog tape recorders. Temperature rhythms were evaluated for 24-hour periodicity, mesor, amplitude, and acrophase using cosinor analysis.
What was found
All subjects' data significantly fit an idealized 24-hour cosine function. Aged men had significantly higher core body temperatures at the nadir of the temperature curve and a significantly lower peak-to-trough rhythm amplitude compared to young men. No significant group differences were found in 24-hour mean temperature, mean temperature during sleep period time, mesor, or acrophase. The abstract does not report numerical values, variances, or exact p-values.
Why it matters
This study shows that age-related reductions in circadian body temperature amplitude, driven by an elevated nocturnal nadir, occur in non-isolated environments and are not artifacts of artificial laboratory isolation.
Limits
The sample size was very small (n = 18 total) and included only men. Recording durations were relatively short (14–24 hours), and the abstract lacks quantitative values and statistical test metrics.
Cited by
- context In order to wake up feeling refreshed and energized, human body temperature must increase by approximately 1 to 3 degrees.