Abstract PS02-04: Associations of sleep health with quality of life among women with newly diagnosed breast cancer: baseline results from the AMBER cohort study
Authors: Yang Lin , Wang Qinggang , McNeil Jessica , Matthews Charles , Dickau Leanne , Vallance Jeff , McNeely Margaret , Culos-Reed S. Nicole , Kopciuk Karen , Courneya Kerry , Friedenreich Christine 
Published: May 2024

Abstract
Background
High incidence, ageing, and advancements in early detection and clinical treatment have led to a growing breast cancer survivor population, particularly in developed countries. Sleep problems are common and persist in this population, affecting over 50% of breast cancer survivors. Good sleep health is characterized by sleep duration, sleep timing and sleep quality, and these three dimensions do not necessarily correlate with each other. This analysis aimed to investigate the associations of sleep health, characterized by sleep duration, sleep timing, and a range of metrics for sleep quality (latency, efficient, disturbance, medication, daytime dysfunction) with physical and mental well-being in women with newly diagnosed breast cancer.
Methods
Newly diagnosed breast cancer patients, with early-stage disease were recruited between 2012-2019 in Edmonton and Calgary, Canada, and completed the Pittsburg Sleep Quality Index (PSQI) to assess the habitual sleep duration and timing, as well as sleep latency, efficiency, disturbance, medication and daytime dysfunction. To measure quality of life, participants completed the SF-36 version-2 to assess their physical and mental well-being. Multivariable linear regressions were used to estimate the association of sleep characteristics with physical and mental well-being, adjusting for socio-demographic, disease, clinical and lifestyle behaviour factors.
Results
Among 1409 breast cancer survivors, 41% reported short or long sleep duration ( &lt; 6 or ≥9 h/d), 41% reported habitual bedtimes after 11pm, 56% reported sleep efficiency being &lt; 85%, 80% reported fairly good (vs. very good) sleep disturbance, 35% reported taking sleep medication in the past month, and 71% reported fairly good, fairly bad or very bad (vs. very good) daytime function. In the multivariable model, short sleep (≤6/d) was associated with worse mental well-being (-3.6, 95%CI: -4.7,-2.4) but not physical well-being (-1.5, 95%CI: -2.3,-0.7). No clinically meaningful differences in quality of life were found for sleep timing. Metrics characterizing suboptimal sleep quality were associated with poorer physical and mental well-being, with stronger associations observed for mental health well-being. Notably, only 20% and 29% women were classified as “very good” in sleep disturbance and daytime dysfunction measures, respectively. Nevertheless, even “fairly good” sleep disturbance and daytime dysfunction were associated with statistically and clinically meaningful significant poorer physical (-3, 95%CI: -3.8,-2.2) and mental (-8, 95%CI: -9,-7) well-being.
Conclusion
Sleep timing does not appear to affect the quality of life in a clinically meaningful manner in women newly diagnosed with breast cancer. In contrast, short sleep duration and worse sleep quality were strongly associated with poorer mental well-being in these women. Targeted interventions to improve sleep may lead to improvements in the quality of life among women with newly diagnosed breast cancer.
Table 1. Association of Sleep Characteristics with SF-36 Measured Quality of Life, Physical Well-Being.
Table 2. Association of Sleep Characteristics with SF-36 Measured Quality of Life, Mental Well-Being.
Citation Format: Lin Yang, Qinggang Wang, Jessica McNeil, Charles Matthews, Leanne Dickau, Jeff Vallance, Margaret McNeely, S. Nicole Culos-Reed, Karen Kopciuk, Kerry Courneya, Christine Friedenreich. Associations of sleep health with quality of life among women with newly diagnosed breast cancer: baseline results from the AMBER cohort study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS02-04.