Abstract

Summary

This doctoral thesis establishes wrist skin temperature as a reliable, non-invasive circadian marker and demonstrates that high day-night contrast in light exposure is associated with more robust circadian and sleep patterns, while nighttime light exposure correlates with worse outcomes. The findings support designing lighting environments with strong day-night contrast and appropriate light quality to maintain circadian health across the lifespan, particularly for aging populations who already exhibit phase advances and reduced synchronizer contrast.
Abstract

Key Findings

  • Day-night contrast in light exposure and light quality were positively associated with more robust wrist temperature rhythms and better sleep patterns, while nighttime light exposure was associated with worse circadian patterns.
  • Aging was associated with a generalized phase advance in the wrist temperature rhythm and reduced contrast in synchronizing variables, allowing mathematical models to distinguish young from elderly individuals without relying on biological age alone.
  • Circadian maturation in infants (n=99) was associated with increasing circadianity of distal skin temperature, while aging (n=80 elderly) was linked to phase advance and internal order impairment.
  • Mathematical modeling demonstrated that increasing day-night contrast in lifestyle variables should improve temperature rhythm robustness.
  • Study included 456 volunteers across age groups: 99 infants, 250 university students, 27 middle-aged adults, and 80 elderly individuals.
Categories

Categories

Sleep & Circadian Health: Establishes wrist skin temperature as a circadian marker rhythm and demonstrates how day-night light contrast and light quality affect circadian robustness and sleep patterns.
Dementia & Elder Care: Characterizes circadian system aging through phase advance, reduced synchronizer contrast, and internal order impairment, comparing elderly vs. young populations.
The Science of Light: Investigates the influence of light exposure quality and timing on circadian rhythms, including the development of a patented healthy circadian lighting device.
Authors

Author(s)

A Mart铆nez Nicol谩s
Publication Date

Publication Year

2014
Citations

Number of Citations

1
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