Exploring the effects of sleep interventions in breast cancer patients taking into account temporal changes in cancer-related fatigue and physical activity

• Applicant: Dr. Alexander Haussmann
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology ; Hematology, Oncology ; Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540707655

Insomnia is one of the most prevalent and burdensome symptoms of individuals with cancer. Cognitive behavioral therapy for insomnia (CBT-I) is considered the gold standard to treat insomnia. Bright light therapy (BLT) was shown to be an effective alternative or adjunct to CBT-I. To date, little research has been done on the mechanisms by which these interventions work in individuals with cancer. To explain their effects, changes in cancer-related fatigue - a distressing exhaustion and tiredness - and physical activity may play a crucial role. Empirical research revealed that insomnia, fatigue, and activity levels reinforce and attenuate each other in heterogeneous patterns. The aim of my proposed research project is to gain unexplored insights into how improvements in sleep behavior in individuals with cancer are influenced by changes in fatigue and physical activity over the course of sleep interventions. In addition, insights will be gained into how sleep and physical activity are associated in daily bi-directional relationships. Data will be used and pooled from the SleepWell and SleepCare study, two randomized controlled trials that investigated the effects of CBT-I and/or BLT on insomnia and fatigue in breast cancer patients (overall N=311). Assessments comprised self-reported data and objective measurements (actigraphy). Statistical analyses will include mixed linear models accounting for inter- and intraindividual variation based on subjective and objective assessments before, during, and after the interventions. Findings will potentially show (intervention) effects of fatigue on insomnia as well as moderating effects of physical activity on the intervention effect and on the impact of fatigue. Additionally, daily bi-directional relationships between physical activity and sleep parameters will be analyzed from two perspectives: (a) effects of physical activity on sleep parameters the following night including possible moderators (i.e., physical activity intensity, timing of physical activity, light exposure, and chronotype) and (b) effects of sleep parameters on physical activity the following day including a potential moderation effect of deviations from the average sleep pattern. The findings from my proposed research project may help increase the impact of future sleep interventions for cancer patients. The differentiated analysis of the role of fatigue and physical activity during a sleep intervention may suggest the inclusion of explicit fatigue management to treat insomnia and could enable more specific activity recommendations for individuals with cancer.

• DFG Programme: WBP Fellowship
• International Connection: Australia
• Host: Dr. Joshua Wiley