Purpose: The purpose of this study was to examine patterns of circadian activity rhythms and their relationship with fatigue, anxiety/depression, and demographic/medical variables in women receiving breast cancer adjuvant therapy treatments (Tx) at three times within a randomized clinical trial (RCT) designed to improve sleep and modify fatigue.
Methods: A RCT enrolled 219 women with stage I-IIIA breast cancer who were randomized 2 days prior to starting chemotherapy to a behavioral therapy sleep intervention or healthy eating control group. All cases with available data (n = 190) were included in a descriptive, correlational, repeated measures analysis. Activity data were collected continuously by wrist actigraphy for 7 days at three times: the start (Tx 1), continuation (Tx 3), and recovery (30 days after last Tx) of chemotherapy. Circadian activity rhythm parameters were generated using Action4 software (Ambulatory Monitoring, Inc.). Measures collected simultaneously included Piper Fatigue Scale, Hospital Anxiety and Depression Scale, and demographic/medical variables.
Results: Circadian activity rhythm parameters at three times in both groups were disrupted compared to healthy adults, but similar to values of cancer patients. Significant changes in mesor, amplitude, peak activity, and 24 h autocorrelation values were found over time in both groups. The intervention group's amplitude and circadian quotient values were significantly more robust. More robust activity rhythms were associated with lower fatigue, depressive symptoms, body mass index, and higher performance status in both groups.
Conclusions: Disrupted patterns of circadian activity rhythms were prevalent and associated with distressing fatigue and depressive symptoms during chemotherapy and at recovery. The intervention resulted in more robust rhythms.