Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort

Abstract Light plays a crucial role in regulating nocturnal sleep patterns. This cross-sectional study evaluated the potential association between levels of light exposure in real-life settings and sleep parameters in individuals with bipolar disorder. We included 204 ambulatory individuals with bip...

Full description

Saved in:
Bibliographic Details
Main Authors: Yuichi Esaki, Kenji Obayashi, Keigo Saeki, Kiyoshi Fujita, Nakao Iwata, Jamie M. Zeitzer, Tsuyoshi Kitajima
Format: Article
Language:English
Published: Nature Publishing Group 2025-08-01
Series:Translational Psychiatry
Online Access:https://doi.org/10.1038/s41398-025-03549-3
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849330501876187136
author Yuichi Esaki
Kenji Obayashi
Keigo Saeki
Kiyoshi Fujita
Nakao Iwata
Jamie M. Zeitzer
Tsuyoshi Kitajima
author_facet Yuichi Esaki
Kenji Obayashi
Keigo Saeki
Kiyoshi Fujita
Nakao Iwata
Jamie M. Zeitzer
Tsuyoshi Kitajima
author_sort Yuichi Esaki
collection DOAJ
description Abstract Light plays a crucial role in regulating nocturnal sleep patterns. This cross-sectional study evaluated the potential association between levels of light exposure in real-life settings and sleep parameters in individuals with bipolar disorder. We included 204 ambulatory individuals with bipolar disorder who participated in the APPLE (Association between Pathology of Bipolar Disorder and Light Exposure in Daily Life) cohort study. Daytime illuminance and sleep were assessed using actigraphy over a seven-day period. In addition, a portable light meter was used to evaluate the illuminance levels in the bedroom during nighttime. The median values of daytime illuminance and nighttime illuminance were 221.8 lux (interquartile range: 150.9–306.9 lux) and 2.3 lux (0.3–9.6 lux), respectively. Multivariable linear regression analyses, adjusting for potential confounders, revealed a significant association between greater daytime illuminance and higher sleep efficiency as well as shorter sleep onset latency and wake after sleep onset. Moreover, the interaction term of daytime and nighttime illuminance demonstrated a significant correlation with sleep efficiency (95% confidence interval [CI], −10.45 to −2.17; P = 0.003), sleep onset latency (95% CI, 0.18 to 0.91; P = 0.004), and wake after sleep onset (95% CI, 13.47 to 50.1; P < 0.001). Our findings indicate the existence of a significant positive correlation between daytime light exposure and sleep parameters in individuals with bipolar disorder. The interaction of increased daytime light and decreased nighttime light appears to be positively associated with sleep quality.
format Article
id doaj-art-ce6985bc82a74449b3a96c7179c9d3c8
institution Kabale University
issn 2158-3188
language English
publishDate 2025-08-01
publisher Nature Publishing Group
record_format Article
series Translational Psychiatry
spelling doaj-art-ce6985bc82a74449b3a96c7179c9d3c82025-08-20T03:46:54ZengNature Publishing GroupTranslational Psychiatry2158-31882025-08-011511610.1038/s41398-025-03549-3Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohortYuichi Esaki0Kenji Obayashi1Keigo Saeki2Kiyoshi Fujita3Nakao Iwata4Jamie M. Zeitzer5Tsuyoshi Kitajima6Department of Psychiatry, Okehazama HospitalDepartment of Epidemiology, Nara Medical University School of MedicineDepartment of Epidemiology, Nara Medical University School of MedicineDepartment of Psychiatry, Okehazama HospitalDepartment of Psychiatry, Fujita Health University School of MedicineDepartment of Psychiatry and Behavioral Sciences, Stanford UniversityDepartment of Psychiatry, Fujita Health University School of MedicineAbstract Light plays a crucial role in regulating nocturnal sleep patterns. This cross-sectional study evaluated the potential association between levels of light exposure in real-life settings and sleep parameters in individuals with bipolar disorder. We included 204 ambulatory individuals with bipolar disorder who participated in the APPLE (Association between Pathology of Bipolar Disorder and Light Exposure in Daily Life) cohort study. Daytime illuminance and sleep were assessed using actigraphy over a seven-day period. In addition, a portable light meter was used to evaluate the illuminance levels in the bedroom during nighttime. The median values of daytime illuminance and nighttime illuminance were 221.8 lux (interquartile range: 150.9–306.9 lux) and 2.3 lux (0.3–9.6 lux), respectively. Multivariable linear regression analyses, adjusting for potential confounders, revealed a significant association between greater daytime illuminance and higher sleep efficiency as well as shorter sleep onset latency and wake after sleep onset. Moreover, the interaction term of daytime and nighttime illuminance demonstrated a significant correlation with sleep efficiency (95% confidence interval [CI], −10.45 to −2.17; P = 0.003), sleep onset latency (95% CI, 0.18 to 0.91; P = 0.004), and wake after sleep onset (95% CI, 13.47 to 50.1; P < 0.001). Our findings indicate the existence of a significant positive correlation between daytime light exposure and sleep parameters in individuals with bipolar disorder. The interaction of increased daytime light and decreased nighttime light appears to be positively associated with sleep quality.https://doi.org/10.1038/s41398-025-03549-3
spellingShingle Yuichi Esaki
Kenji Obayashi
Keigo Saeki
Kiyoshi Fujita
Nakao Iwata
Jamie M. Zeitzer
Tsuyoshi Kitajima
Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort
Translational Psychiatry
title Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort
title_full Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort
title_fullStr Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort
title_full_unstemmed Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort
title_short Interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder: a cross-sectional analysis of the APPLE cohort
title_sort interaction of daytime and nighttime light exposure on objective sleep quality in patients with bipolar disorder a cross sectional analysis of the apple cohort
url https://doi.org/10.1038/s41398-025-03549-3
work_keys_str_mv AT yuichiesaki interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort
AT kenjiobayashi interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort
AT keigosaeki interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort
AT kiyoshifujita interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort
AT nakaoiwata interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort
AT jamiemzeitzer interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort
AT tsuyoshikitajima interactionofdaytimeandnighttimelightexposureonobjectivesleepqualityinpatientswithbipolardisorderacrosssectionalanalysisoftheapplecohort