Impact of seasons and temperatures on the sleep-wake cycle in a French elderly rural population
Sleep Medicine. 2025-07-01; 131: 106510
DOI: 10.1016/j.sleep.2025.106510
Jouvencel A(1), Altena E(2), Pérès K(3), Dartigues JF(4), Amieva H(5), Mayo W(6), Catheline G(7).
Author information:
(1)INCIA, EPHE-PSL, Univ Bordeaux, CNRS, Bordeaux, France. Electronic address:
.
(2)INCIA, EPHE-PSL, Univ Bordeaux, CNRS, Bordeaux, France. Electronic address:
.
(3)INSERM, Bordeaux Population Health Research Center, University of Bordeaux,
UMR, U1219, Bordeaux, France. Electronic address: .
(4)INSERM, Bordeaux Population Health Research Center, University of Bordeaux,
UMR, U1219, Bordeaux, France. Electronic address:
.
(5)INSERM, Bordeaux Population Health Research Center, University of Bordeaux,
UMR, U1219, Bordeaux, France. Electronic address: .
(6)INCIA, EPHE-PSL, Univ Bordeaux, CNRS, Bordeaux, France. Electronic address:
.
(7)INCIA, EPHE-PSL, Univ Bordeaux, CNRS, Bordeaux, France. Electronic address:
.
Sleep is known to be affected by season changes in a temperate climate.
Temperature changes are known to affect sleep directly, but in this context,
season-related changes in the circadian rhythm may play an important role as
well. The objectives of this study were to verify the effect of season and
temperature on sleep parameters of elderly French subjects and to focus on the
sleep-wake cycle. Sleep parameters and sleep-wake cycle parameters were analyzed
through actigraphy while seasonality and temperature were acquired from
recording dates and weather records from online scientific archives. ANOVAs were
carried out to investigate the effect of seasons on actigraphic parameters and
to calculate regression models for temperature. A sample of 157 subjects (49.7 %
women) participated in the study with a mean age of 76.9 ± 4.5 years.
Inter-daily stability of the sleep-wake cycle was higher in autumn and winter
with a higher mean activity during those months. Time in bed was significantly
longer in autumn and winter while there was a similar trend for total sleep
time. Those variables changing with the seasons were negatively linked to
ambient temperature. Not only sleep but also the sleep-wake cycle is impacted by
seasonal changes in elderly French subjects. Seasons should be taken into
consideration when planning sleep-wake cycle recordings in temperate climates,
in particular for longitudinal protocols. Clinical interventions should take
season-related sleep-wake cycle problems into account, particularly in the
elderly, who suffer more often from sleep disorders than other age groups. Since
elderly also suffer more from climate change effects, this study further adds to
the demand for clinical monitoring and housing adaptations for the elderly in
the future.
Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.
DOI: 10.1016/j.sleep.2025.106510
PMID: 40220527 [Indexed for MEDLINE]
Conflict of interest statement: Declaration of competing interest The authors
declare that they have no known competing financial interests or personal
relationships that could have appeared to influence the work reported in this
paper.